core/ndstrides: refactor numpy indexing

core/ndstrides: pub ScalarOrNDArray::to_basic_value_enum
core/codegen: gen_assign to take in value_ty
2024-07-31 09:53:15 +08:00 · 2024-07-31 09:53:15 +08:00 · 2024-07-31 09:53:15 +08:00 · 2024-07-31 09:53:15 +08:00 · 2024-07-31 09:53:15 +08:00 · 2024-07-31 09:53:15 +08:00
92 changed files with 9093 additions and 5961 deletions
--- a/.clang-format
+++ b/.clang-format
@ -0,0 +1,3 @@
+BasedOnStyle: Google
+IndentWidth: 4
+ReflowComments: false
--- a/Cargo.lock
+++ b/Cargo.lock
@ -26,9 +26,9 @@ dependencies = [

 [[package]]
 name = "anstream"
-version = "0.6.14"
+version = "0.6.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "418c75fa768af9c03be99d17643f93f79bbba589895012a80e3452a19ddda15b"
+checksum = "64e15c1ab1f89faffbf04a634d5e1962e9074f2741eef6d97f3c4e322426d526"
 dependencies = [
 "anstyle",
 "anstyle-parse",
@ -41,33 +41,33 @@ dependencies = [

 [[package]]
 name = "anstyle"
-version = "1.0.7"
+version = "1.0.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "038dfcf04a5feb68e9c60b21c9625a54c2c0616e79b72b0fd87075a056ae1d1b"
+checksum = "1bec1de6f59aedf83baf9ff929c98f2ad654b97c9510f4e70cf6f661d49fd5b1"

 [[package]]
 name = "anstyle-parse"
-version = "0.2.4"
+version = "0.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c03a11a9034d92058ceb6ee011ce58af4a9bf61491aa7e1e59ecd24bd40d22d4"
+checksum = "eb47de1e80c2b463c735db5b217a0ddc39d612e7ac9e2e96a5aed1f57616c1cb"
 dependencies = [
 "utf8parse",
 ]

 [[package]]
 name = "anstyle-query"
-version = "1.1.0"
+version = "1.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ad186efb764318d35165f1758e7dcef3b10628e26d41a44bc5550652e6804391"
+checksum = "6d36fc52c7f6c869915e99412912f22093507da8d9e942ceaf66fe4b7c14422a"
 dependencies = [
 "windows-sys",
 ]

 [[package]]
 name = "anstyle-wincon"
-version = "3.0.3"
+version = "3.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "61a38449feb7068f52bb06c12759005cf459ee52bb4adc1d5a7c4322d716fb19"
+checksum = "5bf74e1b6e971609db8ca7a9ce79fd5768ab6ae46441c572e46cf596f59e57f8"
 dependencies = [
 "anstyle",
 "windows-sys",
@ -117,9 +117,9 @@ checksum = "1fd0f2584146f6f2ef48085050886acf353beff7305ebd1ae69500e27c67f64b"

 [[package]]
 name = "cc"
-version = "1.1.0"
+version = "1.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eaff6f8ce506b9773fa786672d63fc7a191ffea1be33f72bbd4aeacefca9ffc8"
+checksum = "2aba8f4e9906c7ce3c73463f62a7f0c65183ada1a2d47e397cc8810827f9694f"

 [[package]]
 name = "cfg-if"
@ -129,9 +129,9 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"

 [[package]]
 name = "clap"
-version = "4.5.9"
+version = "4.5.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "64acc1846d54c1fe936a78dc189c34e28d3f5afc348403f28ecf53660b9b8462"
+checksum = "35723e6a11662c2afb578bcf0b88bf6ea8e21282a953428f240574fcc3a2b5b3"
 dependencies = [
 "clap_builder",
 "clap_derive",
@ -139,9 +139,9 @@ dependencies = [

 [[package]]
 name = "clap_builder"
-version = "4.5.9"
+version = "4.5.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6fb8393d67ba2e7bfaf28a23458e4e2b543cc73a99595511eb207fdb8aede942"
+checksum = "49eb96cbfa7cfa35017b7cd548c75b14c3118c98b423041d70562665e07fb0fa"
 dependencies = [
 "anstream",
 "anstyle",
@ -151,27 +151,27 @@ dependencies = [

 [[package]]
 name = "clap_derive"
-version = "4.5.8"
+version = "4.5.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2bac35c6dafb060fd4d275d9a4ffae97917c13a6327903a8be2153cd964f7085"
+checksum = "5d029b67f89d30bbb547c89fd5161293c0aec155fc691d7924b64550662db93e"
 dependencies = [
 "heck 0.5.0",
 "proc-macro2",
 "quote",
- "syn 2.0.70",
+ "syn 2.0.72",
 ]

 [[package]]
 name = "clap_lex"
-version = "0.7.1"
+version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4b82cf0babdbd58558212896d1a4272303a57bdb245c2bf1147185fb45640e70"
+checksum = "1462739cb27611015575c0c11df5df7601141071f07518d56fcc1be504cbec97"

 [[package]]
 name = "colorchoice"
-version = "1.0.1"
+version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b6a852b24ab71dffc585bcb46eaf7959d175cb865a7152e35b348d1b2960422"
+checksum = "d3fd119d74b830634cea2a0f58bbd0d54540518a14397557951e79340abc28c0"

 [[package]]
 name = "console"
@ -421,7 +421,7 @@ checksum = "4fa4d8d74483041a882adaa9a29f633253a66dde85055f0495c121620ac484b2"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.70",
+ "syn 2.0.72",
 ]

 [[package]]
@ -440,9 +440,9 @@ dependencies = [

 [[package]]
 name = "is_terminal_polyfill"
-version = "1.70.0"
+version = "1.70.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8478577c03552c21db0e2724ffb8986a5ce7af88107e6be5d2ee6e158c12800"
+checksum = "7943c866cc5cd64cbc25b2e01621d07fa8eb2a1a23160ee81ce38704e97b8ecf"

 [[package]]
 name = "itertools"
@ -513,9 +513,9 @@ checksum = "97b3888a4aecf77e811145cadf6eef5901f4782c53886191b2f693f24761847c"

 [[package]]
 name = "libloading"
-version = "0.8.4"
+version = "0.8.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e310b3a6b5907f99202fcdb4960ff45b93735d7c7d96b760fcff8db2dc0e103d"
+checksum = "4979f22fdb869068da03c9f7528f8297c6fd2606bc3a4affe42e6a823fdb8da4"
 dependencies = [
 "cfg-if",
 "windows-targets",
@ -749,7 +749,7 @@ dependencies = [
 "phf_shared 0.11.2",
 "proc-macro2",
 "quote",
- "syn 2.0.70",
+ "syn 2.0.72",
 ]

 [[package]]
@ -778,9 +778,9 @@ checksum = "5be167a7af36ee22fe3115051bc51f6e6c7054c9348e28deb4f49bd6f705a315"

 [[package]]
 name = "portable-atomic"
-version = "1.6.0"
+version = "1.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7170ef9988bc169ba16dd36a7fa041e5c4cbeb6a35b76d4c03daded371eae7c0"
+checksum = "da544ee218f0d287a911e9c99a39a8c9bc8fcad3cb8db5959940044ecfc67265"

 [[package]]
 name = "ppv-lite86"
@ -850,7 +850,7 @@ dependencies = [
 "proc-macro2",
 "pyo3-macros-backend",
 "quote",
- "syn 2.0.70",
+ "syn 2.0.72",
 ]

 [[package]]
@ -863,7 +863,7 @@ dependencies = [
 "proc-macro2",
 "pyo3-build-config",
 "quote",
- "syn 2.0.70",
+ "syn 2.0.72",
 ]

 [[package]]
@ -927,9 +927,9 @@ dependencies = [

 [[package]]
 name = "redox_syscall"
-version = "0.5.2"
+version = "0.5.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c82cf8cff14456045f55ec4241383baeff27af886adb72ffb2162f99911de0fd"
+checksum = "2a908a6e00f1fdd0dfd9c0eb08ce85126f6d8bbda50017e74bc4a4b7d4a926a4"
 dependencies = [
 "bitflags",
 ]
@ -1044,7 +1044,7 @@ checksum = "e0cd7e117be63d3c3678776753929474f3b04a43a080c744d6b0ae2a8c28e222"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.70",
+ "syn 2.0.72",
 ]

 [[package]]
@ -1072,9 +1072,9 @@ dependencies = [

 [[package]]
 name = "similar"
-version = "2.5.0"
+version = "2.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa42c91313f1d05da9b26f267f931cf178d4aba455b4c4622dd7355eb80c6640"
+checksum = "1de1d4f81173b03af4c0cbed3c898f6bff5b870e4a7f5d6f4057d62a7a4b686e"

 [[package]]
 name = "siphasher"
@ -1134,7 +1134,7 @@ dependencies = [
 "proc-macro2",
 "quote",
 "rustversion",
- "syn 2.0.70",
+ "syn 2.0.72",
 ]

 [[package]]
@ -1150,9 +1150,9 @@ dependencies = [

 [[package]]
 name = "syn"
-version = "2.0.70"
+version = "2.0.72"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2f0209b68b3613b093e0ec905354eccaedcfe83b8cb37cbdeae64026c3064c16"
+checksum = "dc4b9b9bf2add8093d3f2c0204471e951b2285580335de42f9d2534f3ae7a8af"
 dependencies = [
 "proc-macro2",
 "quote",
@ -1203,22 +1203,22 @@ dependencies = [

 [[package]]
 name = "thiserror"
-version = "1.0.61"
+version = "1.0.63"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c546c80d6be4bc6a00c0f01730c08df82eaa7a7a61f11d656526506112cc1709"
+checksum = "c0342370b38b6a11b6cc11d6a805569958d54cfa061a29969c3b5ce2ea405724"
 dependencies = [
 "thiserror-impl",
 ]

 [[package]]
 name = "thiserror-impl"
-version = "1.0.61"
+version = "1.0.63"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46c3384250002a6d5af4d114f2845d37b57521033f30d5c3f46c4d70e1197533"
+checksum = "a4558b58466b9ad7ca0f102865eccc95938dca1a74a856f2b57b6629050da261"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.70",
+ "syn 2.0.72",
 ]

 [[package]]
@ -1336,9 +1336,9 @@ checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"

 [[package]]
 name = "version_check"
-version = "0.9.4"
+version = "0.9.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
+checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"

 [[package]]
 name = "walkdir"
@ -1486,5 +1486,5 @@ checksum = "fa4f8080344d4671fb4e831a13ad1e68092748387dfc4f55e356242fae12ce3e"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.70",
+ "syn 2.0.72",
 ]
--- a/flake.lock
+++ b/flake.lock
@ -2,11 +2,11 @@
  "nodes": {
    "nixpkgs": {
      "locked": {
-        "lastModified": 1720418205,
-        "narHash": "sha256-cPJoFPXU44GlhWg4pUk9oUPqurPlCFZ11ZQPk21GTPU=",
+        "lastModified": 1721924956,
+        "narHash": "sha256-Sb1jlyRO+N8jBXEX9Pg9Z1Qb8Bw9QyOgLDNMEpmjZ2M=",
        "owner": "NixOS",
        "repo": "nixpkgs",
-        "rev": "655a58a72a6601292512670343087c2d75d859c1",
+        "rev": "5ad6a14c6bf098e98800b091668718c336effc95",
        "type": "github"
      },
      "original": {
--- a/flake.nix
+++ b/flake.nix
@ -26,7 +26,7 @@
            };
            cargoTestFlags = [ "--features" "test" ];
            passthru.cargoLock = cargoLock;
-            nativeBuildInputs = [ pkgs.python3 pkgs.llvmPackages_14.clang llvm-tools-irrt pkgs.llvmPackages_14.llvm.out llvm-nac3 ];
+            nativeBuildInputs = [ pkgs.python3 (pkgs.wrapClangMulti pkgs.llvmPackages_14.clang) llvm-tools-irrt pkgs.llvmPackages_14.llvm.out llvm-nac3 ];
            buildInputs = [ pkgs.python3 llvm-nac3 ];
            checkInputs = [ (pkgs.python3.withPackages(ps: [ ps.numpy ps.scipy ])) ];
            checkPhase =
@ -151,7 +151,7 @@
        buildInputs = with pkgs; [
          # build dependencies
          packages.x86_64-linux.llvm-nac3
-          llvmPackages_14.clang llvmPackages_14.llvm.out  # for running nac3standalone demos
+          (pkgs.wrapClangMulti llvmPackages_14.clang) llvmPackages_14.llvm.out  # for running nac3standalone demos
          packages.x86_64-linux.llvm-tools-irrt
          cargo
          rustc
@ -163,10 +163,7 @@
          clippy
          pre-commit
          rustfmt
-          rust-analyzer
        ];
-        # https://nixos.wiki/wiki/Rust#Shell.nix_example
-        RUST_SRC_PATH = "${pkgs.rust.packages.stable.rustPlatform.rustLibSrc}";
      };
      devShells.x86_64-linux.msys2 = pkgs.mkShell {
        name = "nac3-dev-shell-msys2";
--- a/nac3artiq/demo/list_cmp.py
+++ b/nac3artiq/demo/list_cmp.py
@ -0,0 +1,24 @@
+from min_artiq import *
+from numpy import int32
+
+
+@nac3
+class EmptyList:
+    core: KernelInvariant[Core]
+
+    def __init__(self):
+        self.core = Core()
+
+    @rpc
+    def get_empty(self) -> list[int32]:
+        return []
+
+    @kernel
+    def run(self):
+        a: list[int32] = self.get_empty()
+        if a != []:
+            raise ValueError
+
+
+if __name__ == "__main__":
+    EmptyList().run()
--- a/nac3artiq/src/lib.rs
+++ b/nac3artiq/src/lib.rs
@ -24,6 +24,7 @@ use std::rc::Rc;
 use std::sync::Arc;

 use inkwell::{
+    context::Context,
    memory_buffer::MemoryBuffer,
    module::{Linkage, Module},
    passes::PassBuilderOptions,
@ -625,7 +626,9 @@ impl Nac3 {
            let buffer = buffer.as_slice().into();
            membuffer.lock().push(buffer);
        })));
-        let size_t = if self.isa == Isa::Host { 64 } else { 32 };
+        let size_t = Context::create()
+            .ptr_sized_int_type(&self.get_llvm_target_machine().get_target_data(), None)
+            .get_bit_width();
        let num_threads = if is_multithreaded() { 4 } else { 1 };
        let thread_names: Vec<String> = (0..num_threads).map(|_| "main".to_string()).collect();
        let threads: Vec<_> = thread_names
@ -644,6 +647,9 @@ impl Nac3 {
                ArtiqCodeGenerator::new("attributes_writeback".to_string(), size_t, self.time_fns);
            let context = inkwell::context::Context::create();
            let module = context.create_module("attributes_writeback");
+            let target_machine = self.llvm_options.create_target_machine().unwrap();
+            module.set_data_layout(&target_machine.get_target_data().get_data_layout());
+            module.set_triple(&target_machine.get_triple());
            let builder = context.create_builder();
            let (_, module, _) = gen_func_impl(
                &context,
--- a/nac3artiq/src/symbol_resolver.rs
+++ b/nac3artiq/src/symbol_resolver.rs
@ -991,8 +991,15 @@ impl InnerResolver {
                }
                _ => unreachable!("must be list"),
            };
-            let ty = ctx.get_llvm_type(generator, elem_ty);
            let size_t = generator.get_size_type(ctx.ctx);
+            let ty = if len == 0
+                && matches!(&*ctx.unifier.get_ty_immutable(elem_ty), TypeEnum::TVar { .. })
+            {
+                // The default type for zero-length lists of unknown element type is size_t
+                size_t.into()
+            } else {
+                ctx.get_llvm_type(generator, elem_ty)
+            };
            let arr_ty = ctx
                .ctx
                .struct_type(&[ty.ptr_type(AddressSpace::default()).into(), size_t.into()], false);
--- a/nac3core/build.rs
+++ b/nac3core/build.rs
@ -3,20 +3,34 @@ use std::{
    env,
    fs::File,
    io::Write,
-    path::Path,
+    path::{Path, PathBuf},
    process::{Command, Stdio},
 };

-fn compile_irrt(irrt_dir: &Path, out_dir: &Path) {
-    let irrt_cpp_path = irrt_dir.join("irrt.cpp");
+const CMD_IRRT_CLANG: &str = "clang-irrt";
+const CMD_IRRT_CLANG_TEST: &str = "clang-irrt-test";
+const CMD_IRRT_LLVM_AS: &str = "llvm-as-irrt";
+
+fn get_out_dir() -> PathBuf {
+    PathBuf::from(env::var("OUT_DIR").unwrap())
+}
+
+fn get_irrt_dir() -> &'static Path {
+    Path::new("irrt")
+}
+
+/// Compile `irrt.cpp` for use in `src/codegen`
+fn compile_irrt_cpp() {
+    let out_dir = get_out_dir();
+    let irrt_dir = get_irrt_dir();

    /*
     * HACK: Sadly, clang doesn't let us emit generic LLVM bitcode.
     * Compiling for WASM32 and filtering the output with regex is the closest we can get.
     */
+    let irrt_cpp_path = irrt_dir.join("irrt.cpp");
    let flags: &[&str] = &[
        "--target=wasm32",
-        irrt_cpp_path.to_str().unwrap(),
        "-x",
        "c++",
        "-fno-discard-value-names",
@ -31,16 +45,18 @@ fn compile_irrt(irrt_dir: &Path, out_dir: &Path) {
        "-S",
        "-Wall",
        "-Wextra",
-        "-Werror=return-type",
-        "-I",
-        irrt_dir.to_str().unwrap(),
        "-o",
        "-",
+        "-I",
+        irrt_dir.to_str().unwrap(),
+        irrt_cpp_path.to_str().unwrap(),
    ];

-    println!("cargo:rerun-if-changed={}", out_dir.to_str().unwrap());
+    // Tell Cargo to rerun if any file under `irrt_dir` (recursive) changes
+    println!("cargo:rerun-if-changed={}", irrt_dir.to_str().unwrap());

-    let output = Command::new("clang-irrt")
+    // Compile IRRT and capture the LLVM IR output
+    let output = Command::new(CMD_IRRT_CLANG)
        .args(flags)
        .output()
        .map(|o| {
@ -53,11 +69,17 @@ fn compile_irrt(irrt_dir: &Path, out_dir: &Path) {
    let output = std::str::from_utf8(&output.stdout).unwrap().replace("\r\n", "\n");
    let mut filtered_output = String::with_capacity(output.len());

-    // (?ms:^define.*?\}$) to capture `define` blocks
-    // (?m:^declare.*?$) to capture `declare` blocks
-    // (?m:^%.+?=\s*type\s*\{.+?\}$) to capture `type` declarations
-    let regex_filter =
-        Regex::new(r"(?ms:^define.*?\}$)|(?m:^declare.*?$)|(?m:^%.+?=\s*type\s*\{.+?\}$)").unwrap();
+    // Filter out irrelevant IR
+    //
+    // Regex:
+    // - `(?ms:^define.*?\}$)` captures LLVM `define` blocks
+    // - `(?m:^declare.*?$)` captures LLVM `declare` lines
+    // - `(?m:^%.+?=\s*type\s*\{.+?\}$)` captures LLVM `type` declarations
+    // - `(?m:^@.+?=.+$)` captures global constants
+    let regex_filter = Regex::new(
+        r"(?ms:^define.*?\}$)|(?m:^declare.*?$)|(?m:^%.+?=\s*type\s*\{.+?\}$)|(?m:^@.+?=.+$)",
+    )
+    .unwrap();
    for f in regex_filter.captures_iter(&output) {
        assert_eq!(f.len(), 1);
        filtered_output.push_str(&f[0]);
@ -68,15 +90,21 @@ fn compile_irrt(irrt_dir: &Path, out_dir: &Path) {
        .unwrap()
        .replace_all(&filtered_output, "");

-    println!("cargo:rerun-if-env-changed=DEBUG_DUMP_IRRT");
-    if env::var("DEBUG_DUMP_IRRT").is_ok() {
+    // For debugging
+    // Doing `DEBUG_DUMP_IRRT=1 cargo build -p nac3core` dumps the LLVM IR generated
+    const DEBUG_DUMP_IRRT: &str = "DEBUG_DUMP_IRRT";
+    println!("cargo:rerun-if-env-changed={DEBUG_DUMP_IRRT}");
+    if env::var(DEBUG_DUMP_IRRT).is_ok() {
        let mut file = File::create(out_dir.join("irrt.ll")).unwrap();
        file.write_all(output.as_bytes()).unwrap();
+
        let mut file = File::create(out_dir.join("irrt-filtered.ll")).unwrap();
        file.write_all(filtered_output.as_bytes()).unwrap();
    }

-    let mut llvm_as = Command::new("llvm-as-irrt")
+    // Assemble the emitted and filtered IR to .bc
+    // That .bc will be integrated into nac3core's codegen
+    let mut llvm_as = Command::new(CMD_IRRT_LLVM_AS)
        .stdin(Stdio::piped())
        .arg("-o")
        .arg(out_dir.join("irrt.bc"))
@ -86,10 +114,13 @@ fn compile_irrt(irrt_dir: &Path, out_dir: &Path) {
    assert!(llvm_as.wait().unwrap().success());
 }

-fn compile_irrt_test(irrt_dir: &Path, out_dir: &Path) {
-    let irrt_test_cpp_path = irrt_dir.join("irrt_test.cpp");
-    let exe_path = out_dir.join("irrt_test.out");
+/// Compile `irrt_test.cpp` for testing
+fn compile_irrt_test_cpp() {
+    let out_dir = get_out_dir();
+    let irrt_dir = get_irrt_dir();

+    let exe_path = out_dir.join("irrt_test.out"); // Output path of the compiled test executable
+    let irrt_test_cpp_path = irrt_dir.join("irrt_test.cpp");
    let flags: &[&str] = &[
        irrt_test_cpp_path.to_str().unwrap(),
        "-x",
@ -107,7 +138,7 @@ fn compile_irrt_test(irrt_dir: &Path, out_dir: &Path) {
        exe_path.to_str().unwrap(),
    ];

-    Command::new("clang-irrt-test")
+    Command::new(CMD_IRRT_CLANG_TEST)
        .args(flags)
        .output()
        .map(|o| {
@ -115,20 +146,15 @@ fn compile_irrt_test(irrt_dir: &Path, out_dir: &Path) {
            o
        })
        .unwrap();
-    println!("cargo:rerun-if-changed={}", out_dir.to_str().unwrap());
+    println!("cargo:rerun-if-changed={}", irrt_dir.to_str().unwrap());
 }

 fn main() {
-    let out_dir = env::var("OUT_DIR").unwrap();
-    let out_dir = Path::new(&out_dir);
-
-    let irrt_dir = Path::new("./irrt");
-
-    compile_irrt(irrt_dir, out_dir);
+    compile_irrt_cpp();

    // https://github.com/rust-lang/cargo/issues/2549
    // `cargo test -F test` to also build `irrt_test.cpp
    if cfg!(feature = "test") {
-        compile_irrt_test(irrt_dir, out_dir);
+        compile_irrt_test_cpp();
    }
 }
--- a/nac3core/irrt/irrt.cpp
+++ b/nac3core/irrt/irrt.cpp
@ -1,5 +1,10 @@
-#include "irrt_everything.hpp"
+#define IRRT_DEFINE_TYPEDEF_INTS
+#include <irrt_everything.hpp>

 /*
-    This file will be read by `clang-irrt` to conveniently produce LLVM IR for `nac3core/codegen`.
-*/
+ * All IRRT implementations.
+ *
+ * We don't have pre-compiled objects, so we are writing all implementations in
+ * headers and concatenate them with `#include` into one massive source file that
+ * contains all the IRRT stuff.
+ */
--- a/nac3core/irrt/irrt.hpp
+++ b/nac3core/irrt/irrt.hpp
@ -1,437 +0,0 @@
-#ifndef IRRT_DONT_TYPEDEF_INTS
-typedef _BitInt(8) int8_t;
-typedef unsigned _BitInt(8) uint8_t;
-typedef _BitInt(32) int32_t;
-typedef unsigned _BitInt(32) uint32_t;
-typedef _BitInt(64) int64_t;
-typedef unsigned _BitInt(64) uint64_t;
-#endif
-
-// NDArray indices are always `uint32_t`.
-typedef uint32_t NDIndex;
-// The type of an index or a value describing the length of a range/slice is
-// always `int32_t`.
-typedef int32_t SliceIndex;
-
-template <typename T>
-static T max(T a, T b) {
-    return a > b ? a : b;
-}
-
-template <typename T>
-static T min(T a, T b) {
-    return a > b ? b : a;
-}
-
-// adapted from GNU Scientific Library: https://git.savannah.gnu.org/cgit/gsl.git/tree/sys/pow_int.c
-// need to make sure `exp >= 0` before calling this function
-template <typename T>
-static T __nac3_int_exp_impl(T base, T exp) {
-    T res = 1;
-    /* repeated squaring method */
-    do {
-        if (exp & 1) {
-            res *= base; /* for n odd */
-        }
-        exp >>= 1;
-        base *= base;
-    } while (exp);
-    return res;
-}
-
-template <typename SizeT>
-static SizeT __nac3_ndarray_calc_size_impl(
-    const SizeT *list_data,
-    SizeT list_len,
-    SizeT begin_idx,
-    SizeT end_idx
-) {
-    __builtin_assume(end_idx <= list_len);
-
-    SizeT num_elems = 1;
-    for (SizeT i = begin_idx; i < end_idx; ++i) {
-        SizeT val = list_data[i];
-        __builtin_assume(val > 0);
-        num_elems *= val;
-    }
-    return num_elems;
-}
-
-template <typename SizeT>
-static void __nac3_ndarray_calc_nd_indices_impl(
-    SizeT index,
-    const SizeT *dims,
-    SizeT num_dims,
-    NDIndex *idxs
-) {
-    SizeT stride = 1;
-    for (SizeT dim = 0; dim < num_dims; dim++) {
-        SizeT i = num_dims - dim - 1;
-        __builtin_assume(dims[i] > 0);
-        idxs[i] = (index / stride) % dims[i];
-        stride *= dims[i];
-    }
-}
-
-template <typename SizeT>
-static SizeT __nac3_ndarray_flatten_index_impl(
-    const SizeT *dims,
-    SizeT num_dims,
-    const NDIndex *indices,
-    SizeT num_indices
-) {
-    SizeT idx = 0;
-    SizeT stride = 1;
-    for (SizeT i = 0; i < num_dims; ++i) {
-        SizeT ri = num_dims - i - 1;
-        if (ri < num_indices) {
-            idx += stride * indices[ri];
-        }
-
-        __builtin_assume(dims[i] > 0);
-        stride *= dims[ri];
-    }
-    return idx;
-}
-
-template <typename SizeT>
-static void __nac3_ndarray_calc_broadcast_impl(
-    const SizeT *lhs_dims,
-    SizeT lhs_ndims,
-    const SizeT *rhs_dims,
-    SizeT rhs_ndims,
-    SizeT *out_dims
-) {
-    SizeT max_ndims = lhs_ndims > rhs_ndims ? lhs_ndims : rhs_ndims;
-
-    for (SizeT i = 0; i < max_ndims; ++i) {
-        const SizeT *lhs_dim_sz = i < lhs_ndims ? &lhs_dims[lhs_ndims - i - 1] : nullptr;
-        const SizeT *rhs_dim_sz = i < rhs_ndims ? &rhs_dims[rhs_ndims - i - 1] : nullptr;
-        SizeT *out_dim = &out_dims[max_ndims - i - 1];
-
-        if (lhs_dim_sz == nullptr) {
-            *out_dim = *rhs_dim_sz;
-        } else if (rhs_dim_sz == nullptr) {
-            *out_dim = *lhs_dim_sz;
-        } else if (*lhs_dim_sz == 1) {
-            *out_dim = *rhs_dim_sz;
-        } else if (*rhs_dim_sz == 1) {
-            *out_dim = *lhs_dim_sz;
-        } else if (*lhs_dim_sz == *rhs_dim_sz) {
-            *out_dim = *lhs_dim_sz;
-        } else {
-            __builtin_unreachable();
-        }
-    }
-}
-
-template <typename SizeT>
-static void __nac3_ndarray_calc_broadcast_idx_impl(
-    const SizeT *src_dims,
-    SizeT src_ndims,
-    const NDIndex *in_idx,
-    NDIndex *out_idx
-) {
-    for (SizeT i = 0; i < src_ndims; ++i) {
-        SizeT src_i = src_ndims - i - 1;
-        out_idx[src_i] = src_dims[src_i] == 1 ? 0 : in_idx[src_i];
-    }
-}
-
-template<typename SizeT>
-static void __nac3_ndarray_strides_from_shape_impl(
-    SizeT ndims,
-    SizeT *shape,
-    SizeT *dst_strides
-) {
-    SizeT stride_product = 1;
-    for (SizeT i = 0; i < ndims; i++) {
-        int dim_i = ndims - i - 1;
-        dst_strides[dim_i] = stride_product;
-        stride_product *= shape[dim_i];
-    }
-}
-
-extern "C" {
-    #define DEF_nac3_int_exp_(T) \
-        T __nac3_int_exp_##T(T base, T exp) {\
-            return __nac3_int_exp_impl(base, exp);\
-        }
-
-    DEF_nac3_int_exp_(int32_t)
-    DEF_nac3_int_exp_(int64_t)
-    DEF_nac3_int_exp_(uint32_t)
-    DEF_nac3_int_exp_(uint64_t)
-
-    SliceIndex __nac3_slice_index_bound(SliceIndex i, const SliceIndex len) {
-        if (i < 0) {
-            i = len + i;
-        }
-        if (i < 0) {
-            return 0;
-        } else if (i > len) {
-            return len;
-        }
-        return i;
-    }
-
-    SliceIndex __nac3_range_slice_len(
-        const SliceIndex start,
-        const SliceIndex end,
-        const SliceIndex step
-    ) {
-        SliceIndex diff = end - start;
-        if (diff > 0 && step > 0) {
-            return ((diff - 1) / step) + 1;
-        } else if (diff < 0 && step < 0) {
-            return ((diff + 1) / step) + 1;
-        } else {
-            return 0;
-        }
-    }
-
-    // Handle list assignment and dropping part of the list when
-    // both dest_step and src_step are +1.
-    // - All the index must *not* be out-of-bound or negative,
-    // - The end index is *inclusive*,
-    // - The length of src and dest slice size should already
-    // be checked: if dest.step == 1 then len(src) <= len(dest) else len(src) == len(dest)
-    SliceIndex __nac3_list_slice_assign_var_size(
-        SliceIndex dest_start,
-        SliceIndex dest_end,
-        SliceIndex dest_step,
-        uint8_t *dest_arr,
-        SliceIndex dest_arr_len,
-        SliceIndex src_start,
-        SliceIndex src_end,
-        SliceIndex src_step,
-        uint8_t *src_arr,
-        SliceIndex src_arr_len,
-        const SliceIndex size
-    ) {
-        /* if dest_arr_len == 0, do nothing since we do not support extending list */
-        if (dest_arr_len == 0) return dest_arr_len;
-        /* if both step is 1, memmove directly, handle the dropping of the list, and shrink size */
-        if (src_step == dest_step && dest_step == 1) {
-            const SliceIndex src_len = (src_end >= src_start) ? (src_end - src_start + 1) : 0;
-            const SliceIndex dest_len = (dest_end >= dest_start) ? (dest_end - dest_start + 1) : 0;
-            if (src_len > 0) {
-                __builtin_memmove(
-                    dest_arr + dest_start * size,
-                    src_arr + src_start * size,
-                    src_len * size
-                );
-            }
-            if (dest_len > 0) {
-                /* dropping */
-                __builtin_memmove(
-                    dest_arr + (dest_start + src_len) * size,
-                    dest_arr + (dest_end + 1) * size,
-                    (dest_arr_len - dest_end - 1) * size
-                );
-            }
-            /* shrink size */
-            return dest_arr_len - (dest_len - src_len);
-        }
-        /* if two range overlaps, need alloca */
-        uint8_t need_alloca =
-            (dest_arr == src_arr)
-            && !(
-                max(dest_start, dest_end) < min(src_start, src_end)
-                || max(src_start, src_end) < min(dest_start, dest_end)
-            );
-        if (need_alloca) {
-            uint8_t *tmp = reinterpret_cast<uint8_t *>(__builtin_alloca(src_arr_len * size));
-            __builtin_memcpy(tmp, src_arr, src_arr_len * size);
-            src_arr = tmp;
-        }
-        SliceIndex src_ind = src_start;
-        SliceIndex dest_ind = dest_start;
-        for (;
-            (src_step > 0) ? (src_ind <= src_end) : (src_ind >= src_end);
-            src_ind += src_step, dest_ind += dest_step
-        ) {
-            /* for constant optimization */
-            if (size == 1) {
-                __builtin_memcpy(dest_arr + dest_ind, src_arr + src_ind, 1);
-            } else if (size == 4) {
-                __builtin_memcpy(dest_arr + dest_ind * 4, src_arr + src_ind * 4, 4);
-            } else if (size == 8) {
-                __builtin_memcpy(dest_arr + dest_ind * 8, src_arr + src_ind * 8, 8);
-            } else {
-                /* memcpy for var size, cannot overlap after previous alloca */
-                __builtin_memcpy(dest_arr + dest_ind * size, src_arr + src_ind * size, size);
-            }
-        }
-        /* only dest_step == 1 can we shrink the dest list. */
-        /* size should be ensured prior to calling this function */
-        if (dest_step == 1 && dest_end >= dest_start) {
-            __builtin_memmove(
-                dest_arr + dest_ind * size,
-                dest_arr + (dest_end + 1) * size,
-                (dest_arr_len - dest_end - 1) * size
-            );
-            return dest_arr_len - (dest_end - dest_ind) - 1;
-        }
-        return dest_arr_len;
-    }
-
-    int32_t __nac3_isinf(double x) {
-        return __builtin_isinf(x);
-    }
-
-    int32_t __nac3_isnan(double x) {
-        return __builtin_isnan(x);
-    }
-
-    double tgamma(double arg);
-
-    double __nac3_gamma(double z) {
-        // Handling for denormals
-        //     | x                 | Python gamma(x) | C tgamma(x) |
-        // --- | ----------------- | --------------- | ----------- |
-        // (1) | nan               | nan             | nan         |
-        // (2) | -inf              | -inf            | inf         |
-        // (3) | inf               | inf             | inf         |
-        // (4) | 0.0               | inf             | inf         |
-        // (5) | {-1.0, -2.0, ...} | inf             | nan         |
-
-        // (1)-(3)
-        if (__builtin_isinf(z) || __builtin_isnan(z)) {
-            return z;
-        }
-
-        double v = tgamma(z);
-
-        // (4)-(5)
-        return __builtin_isinf(v) || __builtin_isnan(v) ? __builtin_inf() : v;
-    }
-
-    double lgamma(double arg);
-
-    double __nac3_gammaln(double x) {
-        // libm's handling of value overflows differs from scipy:
-        // - scipy: gammaln(-inf) -> -inf
-        // - libm : lgamma(-inf) -> inf
-
-        if (__builtin_isinf(x)) {
-            return x;
-        }
-
-        return lgamma(x);
-    }
-
-    double j0(double x);
-
-    double __nac3_j0(double x) {
-        // libm's handling of value overflows differs from scipy:
-        // - scipy: j0(inf) -> nan
-        // - libm : j0(inf) -> 0.0
-
-        if (__builtin_isinf(x)) {
-            return __builtin_nan("");
-        }
-
-        return j0(x);
-    }
-
-    uint32_t __nac3_ndarray_calc_size(
-        const uint32_t *list_data,
-        uint32_t list_len,
-        uint32_t begin_idx,
-        uint32_t end_idx
-    ) {
-        return __nac3_ndarray_calc_size_impl(list_data, list_len, begin_idx, end_idx);
-    }
-
-    uint64_t __nac3_ndarray_calc_size64(
-        const uint64_t *list_data,
-        uint64_t list_len,
-        uint64_t begin_idx,
-        uint64_t end_idx
-    ) {
-        return __nac3_ndarray_calc_size_impl(list_data, list_len, begin_idx, end_idx);
-    }
-
-    void __nac3_ndarray_calc_nd_indices(
-        uint32_t index,
-        const uint32_t* dims,
-        uint32_t num_dims,
-        NDIndex* idxs
-    ) {
-        __nac3_ndarray_calc_nd_indices_impl(index, dims, num_dims, idxs);
-    }
-
-    void __nac3_ndarray_calc_nd_indices64(
-        uint64_t index,
-        const uint64_t* dims,
-        uint64_t num_dims,
-        NDIndex* idxs
-    ) {
-        __nac3_ndarray_calc_nd_indices_impl(index, dims, num_dims, idxs);
-    }
-
-    uint32_t __nac3_ndarray_flatten_index(
-        const uint32_t* dims,
-        uint32_t num_dims,
-        const NDIndex* indices,
-        uint32_t num_indices
-    ) {
-        return __nac3_ndarray_flatten_index_impl(dims, num_dims, indices, num_indices);
-    }
-
-    uint64_t __nac3_ndarray_flatten_index64(
-        const uint64_t* dims,
-        uint64_t num_dims,
-        const NDIndex* indices,
-        uint64_t num_indices
-    ) {
-        return __nac3_ndarray_flatten_index_impl(dims, num_dims, indices, num_indices);
-    }
-
-    void __nac3_ndarray_calc_broadcast(
-        const uint32_t *lhs_dims,
-        uint32_t lhs_ndims,
-        const uint32_t *rhs_dims,
-        uint32_t rhs_ndims,
-        uint32_t *out_dims
-    ) {
-        return __nac3_ndarray_calc_broadcast_impl(lhs_dims, lhs_ndims, rhs_dims, rhs_ndims, out_dims);
-    }
-
-    void __nac3_ndarray_calc_broadcast64(
-        const uint64_t *lhs_dims,
-        uint64_t lhs_ndims,
-        const uint64_t *rhs_dims,
-        uint64_t rhs_ndims,
-        uint64_t *out_dims
-    ) {
-        return __nac3_ndarray_calc_broadcast_impl(lhs_dims, lhs_ndims, rhs_dims, rhs_ndims, out_dims);
-    }
-
-    void __nac3_ndarray_calc_broadcast_idx(
-        const uint32_t *src_dims,
-        uint32_t src_ndims,
-        const NDIndex *in_idx,
-        NDIndex *out_idx
-    ) {
-        __nac3_ndarray_calc_broadcast_idx_impl(src_dims, src_ndims, in_idx, out_idx);
-    }
-
-    void __nac3_ndarray_calc_broadcast_idx64(
-        const uint64_t *src_dims,
-        uint64_t src_ndims,
-        const NDIndex *in_idx,
-        NDIndex *out_idx
-    ) {
-        __nac3_ndarray_calc_broadcast_idx_impl(src_dims, src_ndims, in_idx, out_idx);
-    }
-
-    void __nac3_ndarray_strides_from_shape(uint32_t ndims, uint32_t* shape, uint32_t* dst_strides) {
-        __nac3_ndarray_strides_from_shape_impl(ndims, shape, dst_strides);
-    }
-
-    void __nac3_ndarray_strides_from_shape64(uint64_t ndims, uint64_t* shape, uint64_t* dst_strides) {
-        __nac3_ndarray_strides_from_shape_impl(ndims, shape, dst_strides);
-    }
-}
--- a/nac3core/irrt/irrt/artiq_defs.hpp
+++ b/nac3core/irrt/irrt/artiq_defs.hpp
@ -0,0 +1,39 @@
+#pragma once
+
+#include <irrt/int_defs.hpp>
+
+/*
+This file defines all ARTIQ-specific structures
+*/
+
+/**
+ * @brief ARTIQ's `cslice` object
+ *
+ * See https://docs.rs/cslice/0.3.0/src/cslice/lib.rs.html#33-37
+ */
+template <typename SizeT>
+struct CSlice {
+    const char *base;
+    SizeT len;
+};
+
+/**
+ * @brief Int type of ARTIQ's `Exception` IDs.
+ */
+typedef uint32_t ExceptionId;
+
+/**
+ * @brief ARTIQ's `Exception` object
+ *
+ * See https://github.com/m-labs/artiq/blob/b0d2705c385f64b6e6711c1726cd9178f40b598e/artiq/firmware/libeh/eh_artiq.rs#L1C1-L17C1
+ */
+template <typename SizeT>
+struct Exception {
+    ExceptionId id;
+    CSlice<SizeT> file;
+    uint32_t line;
+    uint32_t column;
+    CSlice<SizeT> function;
+    CSlice<SizeT> message;
+    uint32_t param;
+};
--- a/nac3core/irrt/irrt/core.hpp
+++ b/nac3core/irrt/irrt/core.hpp
@ -0,0 +1,347 @@
+#pragma once
+
+#include <irrt/int_defs.hpp>
+#include <irrt/slice.hpp>
+#include <irrt/utils.hpp>
+
+// NDArray indices are always `uint32_t`.
+using NDIndexInt = uint32_t;
+
+namespace {
+// adapted from GNU Scientific Library:
+// https://git.savannah.gnu.org/cgit/gsl.git/tree/sys/pow_int.c
+// need to make sure `exp >= 0` before calling this function
+template <typename T>
+T __nac3_int_exp_impl(T base, T exp) {
+    T res = 1;
+    /* repeated squaring method */
+    do {
+        if (exp & 1) {
+            res *= base; /* for n odd */
+        }
+        exp >>= 1;
+        base *= base;
+    } while (exp);
+    return res;
+}
+
+template <typename SizeT>
+SizeT __nac3_ndarray_calc_size_impl(const SizeT* list_data, SizeT list_len,
+                                    SizeT begin_idx, SizeT end_idx) {
+    __builtin_assume(end_idx <= list_len);
+
+    SizeT num_elems = 1;
+    for (SizeT i = begin_idx; i < end_idx; ++i) {
+        SizeT val = list_data[i];
+        __builtin_assume(val > 0);
+        num_elems *= val;
+    }
+    return num_elems;
+}
+
+template <typename SizeT>
+void __nac3_ndarray_calc_nd_indices_impl(SizeT index, const SizeT* dims,
+                                         SizeT num_dims, NDIndexInt* idxs) {
+    SizeT stride = 1;
+    for (SizeT dim = 0; dim < num_dims; dim++) {
+        SizeT i = num_dims - dim - 1;
+        __builtin_assume(dims[i] > 0);
+        idxs[i] = (index / stride) % dims[i];
+        stride *= dims[i];
+    }
+}
+
+template <typename SizeT>
+SizeT __nac3_ndarray_flatten_index_impl(const SizeT* dims, SizeT num_dims,
+                                        const NDIndexInt* indices,
+                                        SizeT num_indices) {
+    SizeT idx = 0;
+    SizeT stride = 1;
+    for (SizeT i = 0; i < num_dims; ++i) {
+        SizeT ri = num_dims - i - 1;
+        if (ri < num_indices) {
+            idx += stride * indices[ri];
+        }
+
+        __builtin_assume(dims[i] > 0);
+        stride *= dims[ri];
+    }
+    return idx;
+}
+
+template <typename SizeT>
+void __nac3_ndarray_calc_broadcast_impl(const SizeT* lhs_dims, SizeT lhs_ndims,
+                                        const SizeT* rhs_dims, SizeT rhs_ndims,
+                                        SizeT* out_dims) {
+    SizeT max_ndims = lhs_ndims > rhs_ndims ? lhs_ndims : rhs_ndims;
+
+    for (SizeT i = 0; i < max_ndims; ++i) {
+        const SizeT* lhs_dim_sz =
+            i < lhs_ndims ? &lhs_dims[lhs_ndims - i - 1] : nullptr;
+        const SizeT* rhs_dim_sz =
+            i < rhs_ndims ? &rhs_dims[rhs_ndims - i - 1] : nullptr;
+
+        SizeT* out_dim = &out_dims[max_ndims - i - 1];
+
+        if (lhs_dim_sz == nullptr) {
+            *out_dim = *rhs_dim_sz;
+        } else if (rhs_dim_sz == nullptr) {
+            *out_dim = *lhs_dim_sz;
+        } else if (*lhs_dim_sz == 1) {
+            *out_dim = *rhs_dim_sz;
+        } else if (*rhs_dim_sz == 1) {
+            *out_dim = *lhs_dim_sz;
+        } else if (*lhs_dim_sz == *rhs_dim_sz) {
+            *out_dim = *lhs_dim_sz;
+        } else {
+            __builtin_unreachable();
+        }
+    }
+}
+
+template <typename SizeT>
+void __nac3_ndarray_calc_broadcast_idx_impl(const SizeT* src_dims,
+                                            SizeT src_ndims,
+                                            const NDIndexInt* in_idx,
+                                            NDIndexInt* out_idx) {
+    for (SizeT i = 0; i < src_ndims; ++i) {
+        SizeT src_i = src_ndims - i - 1;
+        out_idx[src_i] = src_dims[src_i] == 1 ? 0 : in_idx[src_i];
+    }
+}
+}  // namespace
+
+extern "C" {
+#define DEF_nac3_int_exp_(T)                   \
+    T __nac3_int_exp_##T(T base, T exp) {      \
+        return __nac3_int_exp_impl(base, exp); \
+    }
+
+DEF_nac3_int_exp_(int32_t);
+DEF_nac3_int_exp_(int64_t);
+DEF_nac3_int_exp_(uint32_t);
+DEF_nac3_int_exp_(uint64_t);
+
+SliceIndex __nac3_slice_index_bound(SliceIndex i, const SliceIndex len) {
+    if (i < 0) {
+        i = len + i;
+    }
+    if (i < 0) {
+        return 0;
+    } else if (i > len) {
+        return len;
+    }
+    return i;
+}
+
+SliceIndex __nac3_range_slice_len(const SliceIndex start, const SliceIndex end,
+                                  const SliceIndex step) {
+    SliceIndex diff = end - start;
+    if (diff > 0 && step > 0) {
+        return ((diff - 1) / step) + 1;
+    } else if (diff < 0 && step < 0) {
+        return ((diff + 1) / step) + 1;
+    } else {
+        return 0;
+    }
+}
+
+// Handle list assignment and dropping part of the list when
+// both dest_step and src_step are +1.
+// - All the index must *not* be out-of-bound or negative,
+// - The end index is *inclusive*,
+// - The length of src and dest slice size should already
+// be checked: if dest.step == 1 then len(src) <= len(dest) else
+// len(src) == len(dest)
+SliceIndex __nac3_list_slice_assign_var_size(
+    SliceIndex dest_start, SliceIndex dest_end, SliceIndex dest_step,
+    uint8_t* dest_arr, SliceIndex dest_arr_len, SliceIndex src_start,
+    SliceIndex src_end, SliceIndex src_step, uint8_t* src_arr,
+    SliceIndex src_arr_len, const SliceIndex size) {
+    /* if dest_arr_len == 0, do nothing since we do not support
+     * extending list
+     */
+    if (dest_arr_len == 0) return dest_arr_len;
+    /* if both step is 1, memmove directly, handle the dropping of
+     * the list, and shrink size */
+    if (src_step == dest_step && dest_step == 1) {
+        const SliceIndex src_len =
+            (src_end >= src_start) ? (src_end - src_start + 1) : 0;
+        const SliceIndex dest_len =
+            (dest_end >= dest_start) ? (dest_end - dest_start + 1) : 0;
+        if (src_len > 0) {
+            __builtin_memmove(dest_arr + dest_start * size,
+                              src_arr + src_start * size, src_len * size);
+        }
+        if (dest_len > 0) {
+            /* dropping */
+            __builtin_memmove(dest_arr + (dest_start + src_len) * size,
+                              dest_arr + (dest_end + 1) * size,
+                              (dest_arr_len - dest_end - 1) * size);
+        }
+        /* shrink size */
+        return dest_arr_len - (dest_len - src_len);
+    }
+    /* if two range overlaps, need alloca */
+    uint8_t need_alloca =
+        (dest_arr == src_arr) &&
+        !(max(dest_start, dest_end) < min(src_start, src_end) ||
+          max(src_start, src_end) < min(dest_start, dest_end));
+    if (need_alloca) {
+        uint8_t* tmp =
+            reinterpret_cast<uint8_t*>(__builtin_alloca(src_arr_len * size));
+        __builtin_memcpy(tmp, src_arr, src_arr_len * size);
+        src_arr = tmp;
+    }
+    SliceIndex src_ind = src_start;
+    SliceIndex dest_ind = dest_start;
+    for (; (src_step > 0) ? (src_ind <= src_end) : (src_ind >= src_end);
+         src_ind += src_step, dest_ind += dest_step) {
+        /* for constant optimization */
+        if (size == 1) {
+            __builtin_memcpy(dest_arr + dest_ind, src_arr + src_ind, 1);
+        } else if (size == 4) {
+            __builtin_memcpy(dest_arr + dest_ind * 4, src_arr + src_ind * 4, 4);
+        } else if (size == 8) {
+            __builtin_memcpy(dest_arr + dest_ind * 8, src_arr + src_ind * 8, 8);
+        } else {
+            /* memcpy for var size, cannot overlap after previous
+             * alloca */
+            __builtin_memcpy(dest_arr + dest_ind * size,
+                             src_arr + src_ind * size, size);
+        }
+    }
+    /* only dest_step == 1 can we shrink the dest list. */
+    /* size should be ensured prior to calling this function */
+    if (dest_step == 1 && dest_end >= dest_start) {
+        __builtin_memmove(
+            dest_arr + dest_ind * size, dest_arr + (dest_end + 1) * size,
+            (dest_arr_len - dest_end - 1) * size + size + size + size);
+        return dest_arr_len - (dest_end - dest_ind) - 1;
+    }
+    return dest_arr_len;
+}
+
+int32_t __nac3_isinf(double x) { return __builtin_isinf(x); }
+
+int32_t __nac3_isnan(double x) { return __builtin_isnan(x); }
+
+double tgamma(double arg);
+
+double __nac3_gamma(double z) {
+    // Handling for denormals
+    //     | x                 | Python gamma(x) | C tgamma(x) |
+    // --- | ----------------- | --------------- | ----------- |
+    // (1) | nan               | nan             | nan         |
+    // (2) | -inf              | -inf            | inf         |
+    // (3) | inf               | inf             | inf         |
+    // (4) | 0.0               | inf             | inf         |
+    // (5) | {-1.0, -2.0, ...} | inf             | nan         |
+
+    // (1)-(3)
+    if (__builtin_isinf(z) || __builtin_isnan(z)) {
+        return z;
+    }
+
+    double v = tgamma(z);
+
+    // (4)-(5)
+    return __builtin_isinf(v) || __builtin_isnan(v) ? __builtin_inf() : v;
+}
+
+double lgamma(double arg);
+
+double __nac3_gammaln(double x) {
+    // libm's handling of value overflows differs from scipy:
+    // - scipy: gammaln(-inf) -> -inf
+    // - libm : lgamma(-inf) -> inf
+
+    if (__builtin_isinf(x)) {
+        return x;
+    }
+
+    return lgamma(x);
+}
+
+double j0(double x);
+
+double __nac3_j0(double x) {
+    // libm's handling of value overflows differs from scipy:
+    // - scipy: j0(inf) -> nan
+    // - libm : j0(inf) -> 0.0
+
+    if (__builtin_isinf(x)) {
+        return __builtin_nan("");
+    }
+
+    return j0(x);
+}
+
+uint32_t __nac3_ndarray_calc_size(const uint32_t* list_data, uint32_t list_len,
+                                  uint32_t begin_idx, uint32_t end_idx) {
+    return __nac3_ndarray_calc_size_impl(list_data, list_len, begin_idx,
+                                         end_idx);
+}
+
+uint64_t __nac3_ndarray_calc_size64(const uint64_t* list_data,
+                                    uint64_t list_len, uint64_t begin_idx,
+                                    uint64_t end_idx) {
+    return __nac3_ndarray_calc_size_impl(list_data, list_len, begin_idx,
+                                         end_idx);
+}
+
+void __nac3_ndarray_calc_nd_indices(uint32_t index, const uint32_t* dims,
+                                    uint32_t num_dims, NDIndexInt* idxs) {
+    __nac3_ndarray_calc_nd_indices_impl(index, dims, num_dims, idxs);
+}
+
+void __nac3_ndarray_calc_nd_indices64(uint64_t index, const uint64_t* dims,
+                                      uint64_t num_dims, NDIndexInt* idxs) {
+    __nac3_ndarray_calc_nd_indices_impl(index, dims, num_dims, idxs);
+}
+
+uint32_t __nac3_ndarray_flatten_index(const uint32_t* dims, uint32_t num_dims,
+                                      const NDIndexInt* indices,
+                                      uint32_t num_indices) {
+    return __nac3_ndarray_flatten_index_impl(dims, num_dims, indices,
+                                             num_indices);
+}
+
+uint64_t __nac3_ndarray_flatten_index64(const uint64_t* dims, uint64_t num_dims,
+                                        const NDIndexInt* indices,
+                                        uint64_t num_indices) {
+    return __nac3_ndarray_flatten_index_impl(dims, num_dims, indices,
+                                             num_indices);
+}
+
+void __nac3_ndarray_calc_broadcast(const uint32_t* lhs_dims, uint32_t lhs_ndims,
+                                   const uint32_t* rhs_dims, uint32_t rhs_ndims,
+                                   uint32_t* out_dims) {
+    return __nac3_ndarray_calc_broadcast_impl(lhs_dims, lhs_ndims, rhs_dims,
+                                              rhs_ndims, out_dims);
+}
+
+void __nac3_ndarray_calc_broadcast64(const uint64_t* lhs_dims,
+                                     uint64_t lhs_ndims,
+                                     const uint64_t* rhs_dims,
+                                     uint64_t rhs_ndims, uint64_t* out_dims) {
+    return __nac3_ndarray_calc_broadcast_impl(lhs_dims, lhs_ndims, rhs_dims,
+                                              rhs_ndims, out_dims);
+}
+
+void __nac3_ndarray_calc_broadcast_idx(const uint32_t* src_dims,
+                                       uint32_t src_ndims,
+                                       const NDIndexInt* in_idx,
+                                       NDIndexInt* out_idx) {
+    __nac3_ndarray_calc_broadcast_idx_impl(src_dims, src_ndims, in_idx,
+                                           out_idx);
+}
+
+void __nac3_ndarray_calc_broadcast_idx64(const uint64_t* src_dims,
+                                         uint64_t src_ndims,
+                                         const NDIndexInt* in_idx,
+                                         NDIndexInt* out_idx) {
+    __nac3_ndarray_calc_broadcast_idx_impl(src_dims, src_ndims, in_idx,
+                                           out_idx);
+}
+}  // extern "C"
--- a/nac3core/irrt/irrt/error_context.hpp
+++ b/nac3core/irrt/irrt/error_context.hpp
@ -0,0 +1,92 @@
+#pragma once
+
+#include <irrt/artiq_defs.hpp>
+#include <irrt/int_defs.hpp>
+#include <irrt/utils.hpp>
+
+namespace {
+/**
+ * @brief A (limited) set of known Exception IDs usable in IRRT
+ */
+struct ErrorContextExceptions {
+    ExceptionId index_error;
+    ExceptionId value_error;
+    ExceptionId assertion_error;
+    ExceptionId runtime_error;
+    ExceptionId type_error;
+};
+
+/**
+ * @brief The IRRT error context object
+ *
+ * This object contains all the details needed to propagate Python-like Exceptions in
+ * IRRT - within IRRT itself or propagate out of extern calls from nac3core.
+ */
+struct ErrorContext {
+    const ErrorContextExceptions *exceptions;
+
+    // Exception thrown by IRRT
+    ExceptionId exception_id;
+    // Points to empty c-string if there is no thrown Exception
+    const char *msg;
+    uint64_t param1;
+    uint64_t param2;
+    uint64_t param3;
+
+    void initialize(const ErrorContextExceptions *exceptions) {
+        this->exceptions = exceptions;
+        clear_error();
+    }
+
+    void clear_error() {
+        // NOTE: Point the msg to an empty str.
+        // Don't set it to nullptr - to implement `has_exception`
+        this->msg = "";
+    }
+
+    void set_exception(ExceptionId exception_id, const char *msg,
+                       uint64_t param1 = 0, uint64_t param2 = 0,
+                       uint64_t param3 = 0) {
+        this->exception_id = exception_id;
+        this->msg = msg;
+        this->param1 = param1;
+        this->param2 = param2;
+        this->param3 = param3;
+    }
+
+    bool has_exception() { return !cstr_utils::is_empty(msg); }
+
+    template <typename SizeT>
+    void get_exception_str(CSlice<SizeT> *dst_str) {
+        dst_str->base = msg;
+        dst_str->len = (SizeT)cstr_utils::length(msg);
+    }
+};
+}  // namespace
+
+extern "C" {
+void __nac3_error_context_initialize(ErrorContext *errctx,
+                                     ErrorContextExceptions *exceptions) {
+    errctx->initialize(exceptions);
+}
+
+bool __nac3_error_context_has_exception(ErrorContext *errctx) {
+    return errctx->has_exception();
+}
+
+void __nac3_error_context_get_exception_str(ErrorContext *errctx,
+                                            CSlice<int32_t> *dst_str) {
+    errctx->get_exception_str<int32_t>(dst_str);
+}
+
+void __nac3_error_context_get_exception_str64(ErrorContext *errctx,
+                                              CSlice<int64_t> *dst_str) {
+    errctx->get_exception_str<int64_t>(dst_str);
+}
+
+// Used for testing
+void __nac3_error_dummy_raise(ErrorContext *errctx) {
+    errctx->set_exception(errctx->exceptions->runtime_error,
+                          "Error thrown from __nac3_error_dummy_raise");
+}
+}
--- a/nac3core/irrt/irrt/int_defs.hpp
+++ b/nac3core/irrt/irrt/int_defs.hpp
@ -0,0 +1,12 @@
+#pragma once
+
+// This is made toggleable since `irrt_test.cpp` itself would include
+// headers that define these typedefs
+#ifdef IRRT_DEFINE_TYPEDEF_INTS
+using int8_t = _BitInt(8);
+using uint8_t = unsigned _BitInt(8);
+using int32_t = _BitInt(32);
+using uint32_t = unsigned _BitInt(32);
+using int64_t = _BitInt(64);
+using uint64_t = unsigned _BitInt(64);
+#endif
--- a/nac3core/irrt/irrt/ndarray/basic.hpp
+++ b/nac3core/irrt/irrt/ndarray/basic.hpp
@ -0,0 +1,315 @@
+#pragma once
+
+#include <irrt/error_context.hpp>
+#include <irrt/int_defs.hpp>
+#include <irrt/ndarray/def.hpp>
+
+namespace {
+namespace ndarray {
+namespace basic {
+namespace util {
+/**
+ * @brief Asserts that `shape` does not contain negative dimensions.
+ *
+ * @param ndims Number of dimensions in `shape`
+ * @param shape The shape to check on
+ */
+template <typename SizeT>
+void assert_shape_no_negative(ErrorContext* errctx, SizeT ndims,
+                              const SizeT* shape) {
+    for (SizeT axis = 0; axis < ndims; axis++) {
+        if (shape[axis] < 0) {
+            errctx->set_exception(
+                errctx->exceptions->value_error,
+                "negative dimensions are not allowed; axis {0} "
+                "has dimension {1}",
+                axis, shape[axis]);
+            return;
+        }
+    }
+}
+
+/**
+ * @brief Returns the number of elements of an ndarray given its shape.
+ *
+ * @param ndims Number of dimensions in `shape`
+ * @param shape The shape of the ndarray
+ */
+template <typename SizeT>
+SizeT calc_size_from_shape(SizeT ndims, const SizeT* shape) {
+    SizeT size = 1;
+    for (SizeT axis = 0; axis < ndims; axis++) size *= shape[axis];
+    return size;
+}
+
+/**
+ * @brief Compute the array indices of the `nth` (0-based) element of an ndarray given only its shape.
+ *
+ * @param ndims Number of elements in `shape` and `indices`
+ * @param shape The shape of the ndarray
+ * @param indices The returned indices indexing the ndarray with shape `shape`.
+ * @param nth The index of the element of interest.
+ */
+template <typename SizeT>
+void set_indices_by_nth(SizeT ndims, const SizeT* shape, SizeT* indices,
+                        SizeT nth) {
+    for (int32_t i = 0; i < ndims; i++) {
+        int32_t axis = ndims - i - 1;
+        int32_t dim = shape[axis];
+
+        indices[axis] = nth % dim;
+        nth /= dim;
+    }
+}
+}  // namespace util
+
+/**
+ * @brief Return the number of elements of an `ndarray`
+ *
+ * This function corresponds to `<an_ndarray>.size`
+ */
+template <typename SizeT>
+SizeT size(const NDArray<SizeT>* ndarray) {
+    return util::calc_size_from_shape(ndarray->ndims, ndarray->shape);
+}
+
+/**
+ * @brief Return of the number of its content of an `ndarray`.
+ *
+ * This function corresponds to `<an_ndarray>.nbytes`.
+ */
+template <typename SizeT>
+SizeT nbytes(const NDArray<SizeT>* ndarray) {
+    return size(ndarray) * ndarray->itemsize;
+}
+
+/**
+ * @brief Update the strides of an ndarray given an ndarray `shape`
+ * and assuming that the ndarray is fully c-contagious.
+ *
+ * You might want to read https://ajcr.net/stride-guide-part-1/.
+ */
+template <typename SizeT>
+void set_strides_by_shape(NDArray<SizeT>* ndarray) {
+    SizeT stride_product = 1;
+    for (SizeT i = 0; i < ndarray->ndims; i++) {
+        int axis = ndarray->ndims - i - 1;
+        ndarray->strides[axis] = stride_product * ndarray->itemsize;
+        stride_product *= ndarray->shape[axis];
+    }
+}
+
+/**
+ * @brief Return the pointer to the element indexed by `indices`.
+ */
+template <typename SizeT>
+uint8_t* get_pelement_by_indices(const NDArray<SizeT>* ndarray,
+                                 const SizeT* indices) {
+    uint8_t* element = ndarray->data;
+    for (SizeT dim_i = 0; dim_i < ndarray->ndims; dim_i++)
+        element += indices[dim_i] * ndarray->strides[dim_i];
+    return element;
+}
+
+/**
+ * @brief Return the pointer to the nth (0-based) element in a flattened view of `ndarray`.
+ */
+template <typename SizeT>
+uint8_t* get_nth_pelement(const NDArray<SizeT>* ndarray, SizeT nth) {
+    SizeT* indices = (SizeT*)__builtin_alloca(sizeof(SizeT) * ndarray->ndims);
+    util::set_indices_by_nth(ndarray->ndims, ndarray->shape, indices, nth);
+    return get_pelement_by_indices(ndarray, indices);
+}
+
+/**
+ * @brief Like `get_nth_pelement` but asserts that `nth` is in bounds.
+ */
+template <typename SizeT>
+uint8_t* checked_get_nth_pelement(ErrorContext* errctx,
+                                  const NDArray<SizeT>* ndarray, SizeT nth) {
+    SizeT arr_size = ndarray->size();
+    if (!(0 <= nth && nth < arr_size)) {
+        errctx->set_exception(
+            errctx->exceptions->index_error,
+            "index {0} is out of bounds, valid range is {1} <= index < {2}",
+            nth, 0, arr_size);
+        return 0;
+    }
+    return get_nth_pelement(ndarray, nth);
+}
+
+/**
+ * @brief Set an element in `ndarray`.
+ *
+ * @param pelement Pointer to the element in `ndarray` to be set.
+ * @param pvalue Pointer to the value `pelement` will be set to.
+ */
+template <typename SizeT>
+void set_pelement_value(NDArray<SizeT>* ndarray, uint8_t* pelement,
+                        const uint8_t* pvalue) {
+    __builtin_memcpy(pelement, pvalue, ndarray->itemsize);
+}
+
+/**
+ * @brief Get the `len()` of an ndarray, and asserts that `ndarray` is a sized object.
+ *
+ * This function corresponds to `<an_ndarray>.__len__`.
+ *
+ * @param dst_length The returned result
+ */
+template <typename SizeT>
+void len(ErrorContext* errctx, const NDArray<SizeT>* ndarray,
+         SliceIndex* dst_length) {
+    // numpy prohibits `__len__` on unsized objects
+    if (ndarray->ndims == 0) {
+        errctx->set_exception(errctx->exceptions->type_error,
+                              "len() of unsized object");
+        return;
+    }
+
+    *dst_length = (SliceIndex)ndarray->shape[0];
+}
+
+/**
+ * @brief Copy data from one ndarray to another of the exact same size and itemsize.
+ *
+ * Both ndarrays will be viewed in their flatten views when copying the elements.
+ */
+template <typename SizeT>
+void copy_data(const NDArray<SizeT>* src_ndarray, NDArray<SizeT>* dst_ndarray) {
+    __builtin_assume(src_ndarray->itemsize == dst_ndarray->itemsize);
+
+    for (SizeT i = 0; i < size(src_ndarray); i++) {
+        auto src_element = ndarray::basic::get_nth_pelement(src_ndarray, i);
+        auto dst_element = ndarray::basic::get_nth_pelement(dst_ndarray, i);
+        ndarray::basic::set_pelement_value(dst_ndarray, dst_element,
+                                           src_element);
+    }
+}
+
+/**
+ * @brief Return a boolean indicating if `ndarray` is (C-)contiguous.
+ *
+ * You may want to see: ndarray's rules for C-contiguity: https://github.com/numpy/numpy/blob/df256d0d2f3bc6833699529824781c58f9c6e697/numpy/core/src/multiarray/flagsobject.c#L95C1-L99C45
+ */
+template <typename SizeT>
+bool is_c_contiguous(const NDArray<SizeT>* ndarray) {
+    // Other references:
+    // - tinynumpy's implementation: https://github.com/wadetb/tinynumpy/blob/0d23d22e07062ffab2afa287374c7b366eebdda1/tinynumpy/tinynumpy.py#L102
+    // - ndarray's flags["C_CONTIGUOUS"]: https://numpy.org/doc/stable/reference/generated/numpy.ndarray.flags.html#numpy.ndarray.flags
+    // - ndarray's rules for C-contiguity: https://github.com/numpy/numpy/blob/df256d0d2f3bc6833699529824781c58f9c6e697/numpy/core/src/multiarray/flagsobject.c#L95C1-L99C45
+
+    // From https://github.com/numpy/numpy/blob/df256d0d2f3bc6833699529824781c58f9c6e697/numpy/core/src/multiarray/flagsobject.c#L95C1-L99C45:
+    //
+    // The traditional rule is that for an array to be flagged as C contiguous,
+    // the following must hold:
+    //
+    // strides[-1] == itemsize
+    // strides[i] == shape[i+1] * strides[i + 1]
+    // [...]
+    // According to these rules, a 0- or 1-dimensional array is either both
+    // C- and F-contiguous, or neither; and an array with 2+ dimensions
+    // can be C- or F- contiguous, or neither, but not both. Though there
+    // there are exceptions for arrays with zero or one item, in the first
+    // case the check is relaxed up to and including the first dimension
+    // with shape[i] == 0. In the second case `strides == itemsize` will
+    // can be true for all dimensions and both flags are set.
+
+    if (ndarray->ndims == 0) {
+        return true;
+    }
+
+    if (ndarray->strides[ndarray->ndims - 1] != ndarray->itemsize) {
+        return false;
+    }
+
+    for (SizeT i = 0; i < ndarray->ndims - 1; i++) {
+        if (ndarray->strides[i] !=
+            ndarray->shape[i + 1] + ndarray->strides[i + 1]) {
+            return false;
+        }
+    }
+
+    return true;
+}
+}  // namespace basic
+}  // namespace ndarray
+}  // namespace
+
+extern "C" {
+using namespace ndarray::basic;
+
+uint32_t __nac3_ndarray_size(NDArray<int32_t>* ndarray) {
+    return size(ndarray);
+}
+
+uint64_t __nac3_ndarray_size64(NDArray<int64_t>* ndarray) {
+    return size(ndarray);
+}
+
+uint32_t __nac3_ndarray_nbytes(NDArray<int32_t>* ndarray) {
+    return nbytes(ndarray);
+}
+
+uint64_t __nac3_ndarray_nbytes64(NDArray<int64_t>* ndarray) {
+    return nbytes(ndarray);
+}
+
+void __nac3_ndarray_len(ErrorContext* errctx, NDArray<int32_t>* ndarray,
+                        SliceIndex* dst_len) {
+    return len(errctx, ndarray, dst_len);
+}
+
+void __nac3_ndarray_len64(ErrorContext* errctx, NDArray<int64_t>* ndarray,
+                          SliceIndex* dst_len) {
+    return len(errctx, ndarray, dst_len);
+}
+
+void __nac3_ndarray_util_assert_shape_no_negative(ErrorContext* errctx,
+                                                  int32_t ndims,
+                                                  int32_t* shape) {
+    util::assert_shape_no_negative(errctx, ndims, shape);
+}
+
+void __nac3_ndarray_util_assert_shape_no_negative64(ErrorContext* errctx,
+                                                    int64_t ndims,
+                                                    int64_t* shape) {
+    util::assert_shape_no_negative(errctx, ndims, shape);
+}
+
+void __nac3_ndarray_set_strides_by_shape(NDArray<int32_t>* ndarray) {
+    set_strides_by_shape(ndarray);
+}
+
+void __nac3_ndarray_set_strides_by_shape64(NDArray<int64_t>* ndarray) {
+    set_strides_by_shape(ndarray);
+}
+
+bool __nac3_ndarray_is_c_contiguous(NDArray<int32_t>* ndarray) {
+    return is_c_contiguous(ndarray);
+}
+
+bool __nac3_ndarray_is_c_contiguous64(NDArray<int64_t>* ndarray) {
+    return is_c_contiguous(ndarray);
+}
+
+void __nac3_ndarray_copy_data(NDArray<int32_t>* src_ndarray,
+                              NDArray<int32_t>* dst_ndarray) {
+    copy_data(src_ndarray, dst_ndarray);
+}
+
+void __nac3_ndarray_copy_data64(NDArray<int64_t>* src_ndarray,
+                                NDArray<int64_t>* dst_ndarray) {
+    copy_data(src_ndarray, dst_ndarray);
+}
+
+uint8_t* __nac3_ndarray_get_nth_pelement(NDArray<int32_t>* ndarray,
+                                         int32_t index) {
+    return get_nth_pelement(ndarray, index);
+}
+
+uint8_t* __nac3_ndarray_get_nth_pelement64(NDArray<int64_t>* ndarray,
+                                           int64_t index) {
+    return get_nth_pelement(ndarray, index);
+}
+}
--- a/nac3core/irrt/irrt/ndarray/broadcast.hpp
+++ b/nac3core/irrt/irrt/ndarray/broadcast.hpp
@ -0,0 +1,221 @@
+#pragma once
+
+#include <irrt/error_context.hpp>
+#include <irrt/int_defs.hpp>
+#include <irrt/ndarray/def.hpp>
+#include <irrt/slice.hpp>
+
+namespace {
+template <typename SizeT>
+struct ShapeEntry {
+    SizeT ndims;
+    SizeT* shape;
+};
+}  // namespace
+
+namespace {
+namespace ndarray {
+namespace broadcast {
+namespace util {
+/**
+ * @brief Return true if `src_shape` can broadcast to `dst_shape`.
+ */
+template <typename SizeT>
+bool can_broadcast_shape_to(SizeT target_ndims, const SizeT* target_shape,
+                            SizeT src_ndims, const SizeT* src_shape) {
+    /*
+     *  // See https://numpy.org/doc/stable/user/basics.broadcasting.html
+
+     *  This function handles this example:
+     *  ```
+     *  Image  (3d array): 256 x 256 x 3
+     *  Scale  (1d array):             3
+     *  Result (3d array): 256 x 256 x 3
+     *  ```
+
+     *  Other interesting examples to consider:
+     *  - `can_broadcast_shape_to([3], [1, 1, 1, 1, 3]) == true`
+     *  - `can_broadcast_shape_to([3], [3, 1]) == false`
+     *  - `can_broadcast_shape_to([256, 256, 3], [256, 1, 3]) == true`
+
+     *  In cases when the shapes contain zero(es):
+     *  - `can_broadcast_shape_to([0], [1]) == true`
+     *  - `can_broadcast_shape_to([0], [2]) == false`
+     *  - `can_broadcast_shape_to([0, 4, 0, 0], [1]) == true`
+     *  - `can_broadcast_shape_to([0, 4, 0, 0], [1, 1, 1, 1]) == true`
+     *  - `can_broadcast_shape_to([0, 4, 0, 0], [1, 4, 1, 1]) == true`
+     *  - `can_broadcast_shape_to([4, 3], [0, 3]) == false`
+     *  - `can_broadcast_shape_to([4, 3], [0, 0]) == false`
+     */
+
+    // This is essentially doing the following in Python:
+    // `for target_dim, src_dim in itertools.zip_longest(target_shape[::-1], src_shape[::-1], fillvalue=1)`
+    for (SizeT i = 0; i < max(target_ndims, src_ndims); i++) {
+        SizeT target_dim_i = target_ndims - i - 1;
+        SizeT src_dim_i = src_ndims - i - 1;
+
+        bool target_dim_exists = target_dim_i >= 0;
+        bool src_dim_exists = src_dim_i >= 0;
+
+        SizeT target_dim = target_dim_exists ? target_shape[target_dim_i] : 1;
+        SizeT src_dim = src_dim_exists ? src_shape[src_dim_i] : 1;
+
+        bool ok = src_dim == 1 || target_dim == src_dim;
+        if (!ok) return false;
+    }
+
+    return true;
+}
+
+/**
+ * @brief Performs `np.broadcast_shapes`
+ */
+template <typename SizeT>
+void broadcast_shapes(ErrorContext* errctx, SizeT num_shapes,
+                      const ShapeEntry<SizeT>* shapes, SizeT dst_ndims,
+                      SizeT* dst_shape) {
+    // `dst_ndims` must be `max([shape.ndims for shape in shapes])`, but the caller has to calculate it/provide it
+    //   for this function since it should already know in order to allocate `dst_shape` in the first place.
+    // `dst_shape` must be pre-allocated.
+    // `dst_shape` does not have to be initialized
+
+    // TODO: Implementation is not obvious
+
+    // This is essentially a `mconcat` where the neutral element is `[1, 1, 1, 1, ...]`, and the operation is commutative.
+
+    // Set `dst_shape` to all `1`s.
+    for (SizeT dst_axis = 0; dst_axis < dst_ndims; dst_axis++) {
+        dst_shape[dst_axis] = 0;
+    }
+
+    for (SizeT i = 0; i < num_shapes; i++) {
+        ShapeEntry<SizeT> entry = shapes[i];
+        SizeT entry_axis = entry.ndims - i;
+        SizeT dst_axis = dst_ndims - i;
+
+        SizeT entry_dim = entry.shape[entry_axis];
+        SizeT dst_dim = dst_shape[dst_axis];
+
+        if (dst_dim == 1) {
+            dst_shape[dst_axis] = entry_dim;
+        } else if (entry_dim == 1) {
+            // Do nothing
+        } else if (entry_dim == dst_dim) {
+            // Do nothing
+        } else {
+            errctx->set_exception(errctx->exceptions->value_error,
+                                  "shape mismatch: objects cannot be broadcast "
+                                  "to a single shape.");
+            return;
+        }
+    }
+}
+}  // namespace util
+
+/**
+ * @brief Perform `np.broadcast_to(<ndarray>, <target_shape>)` and appropriate assertions.
+ *
+ * Cautious note on https://github.com/numpy/numpy/issues/21744..
+ *
+ * This function attempts to broadcast `src_ndarray` to a new shape defined by `dst_ndarray.shape`,
+ * and return the result by modifying `dst_ndarray`.
+ *
+ * # Notes on `dst_ndarray`
+ * The caller is responsible for allocating space for the resulting ndarray.
+ * Here is what this function expects from `dst_ndarray` when called:
+ *   - `dst_ndarray->data` does not have to be initialized.
+ *   - `dst_ndarray->itemsize` does not have to be initialized.
+ *   - `dst_ndarray->ndims` must be initialized, determining the length of `dst_ndarray->shape`
+ *   - `dst_ndarray->shape` must be allocated, and must contain the desired target broadcast shape.
+ *   - `dst_ndarray->strides` must be allocated, through it can contain uninitialized values.
+ * When this function call ends:
+ *   - `dst_ndarray->data` is set to `src_ndarray->data` (`dst_ndarray` is just a view to `src_ndarray`)
+ *   - `dst_ndarray->itemsize` is set to `src_ndarray->itemsize`
+ *   - `dst_ndarray->ndims` is unchanged.
+ *   - `dst_ndarray->shape` is unchanged.
+ *   - `dst_ndarray->strides` is updated accordingly by how ndarray broadcast_to works.
+ */
+template <typename SizeT>
+void broadcast_to(ErrorContext* errctx, const NDArray<SizeT>* src_ndarray,
+                  NDArray<SizeT>* dst_ndarray) {
+    /*
+     * Cautions:
+     *   ```
+     *   xs = np.zeros((4,))
+     *   ys = np.zero((4, 1))
+     *   ys[:] = xs # ok
+     *
+     *   xs = np.zeros((1, 4))
+     *   ys = np.zero((4,))
+     *   ys[:] = xs # allowed
+     *   # However `np.broadcast_to(xs, (4,))` would fails, as per numpy's broadcasting rule.
+     *   # and apparently numpy will "deprecate" this? SEE https://github.com/numpy/numpy/issues/21744
+     *   # This implementation will NOT support this assignment.
+     *   ```
+    */
+
+    if (!ndarray::broadcast::util::can_broadcast_shape_to(
+            dst_ndarray->ndims, dst_ndarray->shape, src_ndarray->ndims,
+            src_ndarray->shape)) {
+        errctx->set_exception(errctx->exceptions->value_error,
+                              "operands could not be broadcast together");
+        return;
+    }
+
+    dst_ndarray->data = src_ndarray->data;
+    dst_ndarray->itemsize = src_ndarray->itemsize;
+
+    // TODO: Implementation is not obvious
+    SizeT stride_product = 1;
+    for (SizeT i = 0; i < max(src_ndarray->ndims, dst_ndarray->ndims); i++) {
+        SizeT src_ndarray_dim_i = src_ndarray->ndims - i - 1;
+        SizeT dst_dim_i = dst_ndarray->ndims - i - 1;
+
+        bool src_ndarray_dim_exists = src_ndarray_dim_i >= 0;
+        bool dst_dim_exists = dst_dim_i >= 0;
+
+        bool c1 = src_ndarray_dim_exists &&
+                  src_ndarray->shape[src_ndarray_dim_i] == 1;
+        bool c2 = dst_dim_exists && dst_ndarray->shape[dst_dim_i] != 1;
+        if (!src_ndarray_dim_exists || (c1 && c2)) {
+            dst_ndarray->strides[dst_dim_i] = 0;  // Freeze it in-place
+        } else {
+            dst_ndarray->strides[dst_dim_i] =
+                stride_product * src_ndarray->itemsize;
+            stride_product *= src_ndarray->shape[src_ndarray_dim_i];
+        }
+    }
+}
+}  // namespace broadcast
+}  // namespace ndarray
+}  // namespace
+
+extern "C" {
+using namespace ndarray::broadcast;
+
+void __nac3_ndarray_broadcast_to(ErrorContext* errctx,
+                                 NDArray<int32_t>* src_ndarray,
+                                 NDArray<int32_t>* dst_ndarray) {
+    broadcast_to(errctx, src_ndarray, dst_ndarray);
+}
+
+void __nac3_ndarray_broadcast_to64(ErrorContext* errctx,
+                                   NDArray<int64_t>* src_ndarray,
+                                   NDArray<int64_t>* dst_ndarray) {
+    broadcast_to(errctx, src_ndarray, dst_ndarray);
+}
+
+void __nac3_ndarray_broadcast_shapes(ErrorContext* errctx, int32_t num_shapes,
+                                     const ShapeEntry<int32_t>* shapes,
+                                     int32_t dst_ndims, int32_t* dst_shape) {
+    ndarray::broadcast::util::broadcast_shapes(errctx, num_shapes, shapes,
+                                               dst_ndims, dst_shape);
+}
+
+void __nac3_ndarray_broadcast_shapes64(ErrorContext* errctx, int64_t num_shapes,
+                                       const ShapeEntry<int64_t>* shapes,
+                                       int64_t dst_ndims, int64_t* dst_shape) {
+    ndarray::broadcast::util::broadcast_shapes(errctx, num_shapes, shapes,
+                                               dst_ndims, dst_shape);
+}
+}
--- a/nac3core/irrt/irrt/ndarray/def.hpp
+++ b/nac3core/irrt/irrt/ndarray/def.hpp
@ -0,0 +1,44 @@
+#pragma once
+
+namespace {
+/**
+ * @brief The NDArray object
+ *
+ * The official numpy implementations: https://github.com/numpy/numpy/blob/735a477f0bc2b5b84d0e72d92f224bde78d4e069/doc/source/reference/c-api/types-and-structures.rst
+ */
+template <typename SizeT>
+struct NDArray {
+    /**
+     * @brief The underlying data this `ndarray` is pointing to.
+     *
+     * Must be set to `nullptr` to indicate that this NDArray's `data` is uninitialized.
+     */
+    uint8_t* data;
+
+    /**
+     * @brief The number of bytes of a single element in `data`.
+     */
+    SizeT itemsize;
+
+    /**
+     * @brief The number of dimensions of this shape.
+     */
+    SizeT ndims;
+
+    /**
+     * @brief The NDArray shape, with length equal to `ndims`.
+     *
+     * Note that it may contain 0.
+     */
+    SizeT* shape;
+
+    /**
+     * @brief Array strides, with length equal to `ndims`
+     *
+     * The stride values are in units of bytes, not number of elements.
+     *
+     * Note that `strides` can have negative values.
+     */
+    SizeT* strides;
+};
+}  // namespace
--- a/nac3core/irrt/irrt/ndarray/indexing.hpp
+++ b/nac3core/irrt/irrt/ndarray/indexing.hpp
@ -0,0 +1,200 @@
+#pragma once
+
+#include <irrt/error_context.hpp>
+#include <irrt/ndarray/basic.hpp>
+#include <irrt/ndarray/def.hpp>
+#include <irrt/slice.hpp>
+
+namespace {
+typedef uint8_t NDIndexType;
+
+/**
+ * @brief A single element index
+ *
+ * See https://numpy.org/doc/stable/user/basics.indexing.html#single-element-indexing
+ *
+ * `data` points to a `SliceIndex`.
+ */
+const NDIndexType ND_INDEX_TYPE_SINGLE_ELEMENT = 0;
+/**
+ * @brief A slice index
+ *
+ * See https://numpy.org/doc/stable/user/basics.indexing.html#slicing-and-striding
+ *
+ * `data` points to a `UserRange`.
+ */
+const NDIndexType ND_INDEX_TYPE_SLICE = 1;
+
+/**
+ * @brief An index used in ndarray indexing
+ */
+struct NDIndex {
+    /**
+     * @brief Enum tag to specify the type of index.
+     *
+     * Please see comments of each enum constant.
+     */
+    NDIndexType type;
+
+    /**
+     * @brief The accompanying data associated with `type`.
+     *
+     * Please see comments of each enum constant.
+     */
+    uint8_t* data;
+};
+}  // namespace
+
+namespace {
+namespace ndarray {
+namespace indexing {
+namespace util {
+
+/**
+ * @brief Return the expected rank of the resulting ndarray
+ * created by indexing an ndarray of rank `ndims` using `indexes`.
+ */
+template <typename SizeT>
+void deduce_ndims_after_indexing(ErrorContext* errctx, SizeT* final_ndims,
+                                 SizeT ndims, SizeT num_indexes,
+                                 const NDIndex* indexes) {
+    if (num_indexes > ndims) {
+        errctx->set_exception(errctx->exceptions->index_error,
+                              "too many indices for array: array is "
+                              "{0}-dimensional, but {1} were indexed",
+                              ndims, num_indexes);
+        return;
+    }
+
+    *final_ndims = ndims;
+    for (SizeT i = 0; i < num_indexes; i++) {
+        if (indexes[i].type == ND_INDEX_TYPE_SINGLE_ELEMENT) {
+            // An index demotes the rank by 1
+            (*final_ndims)--;
+        }
+    }
+}
+}  // namespace util
+
+/**
+ * @brief Perform ndarray "basic indexing" (https://numpy.org/doc/stable/user/basics.indexing.html#basic-indexing)
+ *
+ * This is function very similar to performing `dst_ndarray = src_ndarray[indexes]` in Python (where the variables
+ * can all be found in the parameter of this function).
+ *
+ * In other words, this function takes in an ndarray (`src_ndarray`), index it with `indexes`, and return the
+ * indexed array (by writing the result to `dst_ndarray`).
+ *
+ * This function also does proper assertions on `indexes`.
+ *
+ * # Notes on `dst_ndarray`
+ * The caller is responsible for allocating space for the resulting ndarray.
+ * Here is what this function expects from `dst_ndarray` when called:
+ *   - `dst_ndarray->data` does not have to be initialized.
+ *   - `dst_ndarray->itemsize` does not have to be initialized.
+ *   - `dst_ndarray->ndims` must be initialized, and it must be equal to the expected `ndims` of the `dst_ndarray` after
+ *       indexing `src_ndarray` with `indexes`.
+ *   - `dst_ndarray->shape` must be allocated, through it can contain uninitialized values.
+ *   - `dst_ndarray->strides` must be allocated, through it can contain uninitialized values.
+ * When this function call ends:
+ *   - `dst_ndarray->data` is set to `src_ndarray->data` (`dst_ndarray` is just a view to `src_ndarray`)
+ *   - `dst_ndarray->itemsize` is set to `src_ndarray->itemsize`
+ *   - `dst_ndarray->ndims` is unchanged.
+ *   - `dst_ndarray->shape` is updated according to how `src_ndarray` is indexed.
+ *   - `dst_ndarray->strides` is updated accordingly by how ndarray indexing works.
+ *
+ * @param indexes Indexes to index `src_ndarray`, ordered in the same way you would write them in Python.
+ * @param src_ndarray The NDArray to be indexed.
+ * @param dst_ndarray The resulting NDArray after indexing. Further details in the comments above,
+ */
+template <typename SizeT>
+void index(ErrorContext* errctx, SizeT num_indexes, const NDIndex* indexes,
+           const NDArray<SizeT>* src_ndarray, NDArray<SizeT>* dst_ndarray) {
+    // Reference code: https://github.com/wadetb/tinynumpy/blob/0d23d22e07062ffab2afa287374c7b366eebdda1/tinynumpy/tinynumpy.py#L652
+
+    dst_ndarray->data = src_ndarray->data;
+    dst_ndarray->itemsize = src_ndarray->itemsize;
+
+    SizeT src_axis = 0;
+    SizeT dst_axis = 0;
+
+    for (SliceIndex i = 0; i < num_indexes; i++) {
+        const NDIndex* index = &indexes[i];
+        if (index->type == ND_INDEX_TYPE_SINGLE_ELEMENT) {
+            SliceIndex input = *((SliceIndex*)index->data);
+            SliceIndex k = slice::resolve_index_in_length(
+                src_ndarray->shape[src_axis], input);
+
+            if (k == slice::OUT_OF_BOUNDS) {
+                errctx->set_exception(errctx->exceptions->index_error,
+                                      "index {0} is out of bounds for axis {1} "
+                                      "with size {2}",
+                                      input, src_axis,
+                                      src_ndarray->shape[src_axis]);
+                return;
+            }
+
+            dst_ndarray->data += k * src_ndarray->strides[src_axis];
+
+            src_axis++;
+        } else if (index->type == ND_INDEX_TYPE_SLICE) {
+            UserSlice* input = (UserSlice*)index->data;
+
+            Slice slice;
+            input->indices_checked(errctx, src_ndarray->shape[src_axis],
+                                   &slice);
+            if (errctx->has_exception()) {
+                return;
+            }
+
+            dst_ndarray->data +=
+                (SizeT)slice.start * src_ndarray->strides[src_axis];
+            dst_ndarray->strides[dst_axis] =
+                ((SizeT)slice.step) * src_ndarray->strides[src_axis];
+            dst_ndarray->shape[dst_axis] = (SizeT)slice.len();
+
+            dst_axis++;
+            src_axis++;
+        } else {
+            __builtin_unreachable();
+        }
+    }
+
+    for (; dst_axis < dst_ndarray->ndims; dst_axis++, src_axis++) {
+        dst_ndarray->shape[dst_axis] = src_ndarray->shape[src_axis];
+        dst_ndarray->strides[dst_axis] = src_ndarray->strides[src_axis];
+    }
+}
+}  // namespace indexing
+}  // namespace ndarray
+}  // namespace
+
+extern "C" {
+using namespace ndarray::indexing;
+
+void __nac3_ndarray_indexing_deduce_ndims_after_indexing(
+    ErrorContext* errctx, int32_t* result, int32_t ndims, int32_t num_indexes,
+    const NDIndex* indexes) {
+    ndarray::indexing::util::deduce_ndims_after_indexing(errctx, result, ndims,
+                                                         num_indexes, indexes);
+}
+
+void __nac3_ndarray_indexing_deduce_ndims_after_indexing64(
+    ErrorContext* errctx, int64_t* result, int64_t ndims, int64_t num_indexes,
+    const NDIndex* indexes) {
+    ndarray::indexing::util::deduce_ndims_after_indexing(errctx, result, ndims,
+                                                         num_indexes, indexes);
+}
+
+void __nac3_ndarray_index(ErrorContext* errctx, int32_t num_indexes,
+                          NDIndex* indexes, NDArray<int32_t>* src_ndarray,
+                          NDArray<int32_t>* dst_ndarray) {
+    index(errctx, num_indexes, indexes, src_ndarray, dst_ndarray);
+}
+
+void __nac3_ndarray_index64(ErrorContext* errctx, int64_t num_indexes,
+                            NDIndex* indexes, NDArray<int64_t>* src_ndarray,
+                            NDArray<int64_t>* dst_ndarray) {
+    index(errctx, num_indexes, indexes, src_ndarray, dst_ndarray);
+}
+}
--- a/nac3core/irrt/irrt/ndarray/reshape.hpp
+++ b/nac3core/irrt/irrt/ndarray/reshape.hpp
@ -0,0 +1,117 @@
+#pragma once
+
+#include <irrt/error_context.hpp>
+#include <irrt/int_defs.hpp>
+#include <irrt/ndarray/def.hpp>
+
+namespace {
+namespace ndarray {
+namespace reshape {
+namespace util {
+
+/**
+ * @brief Perform assertions on and resolve unknown dimensions in `new_shape` in `np.reshape(<ndarray>, new_shape)`
+ *
+ * If `new_shape` indeed contains unknown dimensions (specified with `-1`, just like numpy), `new_shape` will be
+ * modified to contain the resolved dimension.
+ *
+ * To perform assertions on and resolve unknown dimensions in `new_shape`, we don't need the actual
+ * `<ndarray>` object itself, but only the `.size` of the `<ndarray>`.
+ *
+ * @param size The `.size` of `<ndarray>`
+ * @param new_ndims Number of elements in `new_shape`
+ * @param new_shape Target shape to reshape to
+ */
+template <typename SizeT>
+void resolve_and_check_new_shape(ErrorContext* errctx, SizeT size,
+                                 SizeT new_ndims, SizeT* new_shape) {
+    // Is there a -1 in `new_shape`?
+    bool neg1_exists = false;
+    // Location of -1, only initialized if `neg1_exists` is true
+    SizeT neg1_axis_i;
+    // The computed ndarray size of `new_shape`
+    SizeT new_size = 1;
+
+    for (SizeT axis_i = 0; axis_i < new_ndims; axis_i++) {
+        SizeT dim = new_shape[axis_i];
+        if (dim < 0) {
+            if (dim == -1) {
+                if (neg1_exists) {
+                    // Multiple `-1` found. Throw an error.
+                    errctx->set_exception(
+                        errctx->exceptions->value_error,
+                        "can only specify one unknown dimension");
+                    return;
+                } else {
+                    neg1_exists = true;
+                    neg1_axis_i = axis_i;
+                }
+            } else {
+                // TODO: What? In `np.reshape` any negative dimensions is
+                // treated like its `-1`.
+                //
+                // Try running `np.zeros((3, 4)).reshape((-999, 2))`
+                //
+                // It is not documented by numpy.
+                // Throw an error for now...
+
+                errctx->set_exception(
+                    errctx->exceptions->value_error,
+                    "Found negative dimension {0} on axis {1}", dim, axis_i);
+                return;
+            }
+        } else {
+            new_size *= dim;
+        }
+    }
+
+    bool can_reshape;
+    if (neg1_exists) {
+        // Let `x` be the unknown dimension
+        // solve `x * <new_size> = <size>`
+        if (new_size == 0 && size == 0) {
+            // `x` has infinitely many solutions
+            can_reshape = false;
+        } else if (new_size == 0 && size != 0) {
+            // `x` has no solutions
+            can_reshape = false;
+        } else if (size % new_size != 0) {
+            // `x` has no integer solutions
+            can_reshape = false;
+        } else {
+            can_reshape = true;
+            new_shape[neg1_axis_i] = size / new_size;  // Resolve dimension
+        }
+    } else {
+        can_reshape = (new_size == size);
+    }
+
+    if (!can_reshape) {
+        errctx->set_exception(
+            errctx->exceptions->value_error,
+            "cannot reshape array of size {0} into given shape", size);
+        return;
+    }
+}
+}  // namespace util
+}  // namespace reshape
+}  // namespace ndarray
+}  // namespace
+
+extern "C" {
+
+void __nac3_ndarray_resolve_and_check_new_shape(ErrorContext* errctx,
+                                                int32_t size, int32_t new_ndims,
+                                                int32_t* new_shape) {
+    ndarray::reshape::util::resolve_and_check_new_shape(errctx, size, new_ndims,
+                                                        new_shape);
+}
+
+void __nac3_ndarray_resolve_and_check_new_shape64(ErrorContext* errctx,
+                                                  int64_t size,
+                                                  int64_t new_ndims,
+                                                  int64_t* new_shape) {
+    ndarray::reshape::util::resolve_and_check_new_shape(errctx, size, new_ndims,
+                                                        new_shape);
+}
+}
--- a/nac3core/irrt/irrt/slice.hpp
+++ b/nac3core/irrt/irrt/slice.hpp
@ -0,0 +1,166 @@
+#pragma once
+
+#include <irrt/error_context.hpp>
+#include <irrt/int_defs.hpp>
+#include <irrt/slice.hpp>
+#include <irrt/utils.hpp>
+
+// The type of an index or a value describing the length of a
+// range/slice is always `int32_t`.
+using SliceIndex = int32_t;
+
+namespace {
+
+/**
+ * @brief A Python-like slice with resolved indices.
+ *
+ * "Resolved indices" means that `start` and `stop` must be positive and are
+ * bound to a known length.
+ */
+struct Slice {
+    SliceIndex start;
+    SliceIndex stop;
+    SliceIndex step;
+
+    /**
+     * @brief Calculate and return the length / the number of the slice.
+     * 
+     * If this were a Python range, this function would be `len(range(start, stop, step))`.
+     */
+    SliceIndex len() {
+        SliceIndex diff = stop - start;
+        if (diff > 0 && step > 0) {
+            return ((diff - 1) / step) + 1;
+        } else if (diff < 0 && step < 0) {
+            return ((diff + 1) / step) + 1;
+        } else {
+            return 0;
+        }
+    }
+};
+
+namespace slice {
+/**
+ * @brief Resolve a slice index under a given length like Python indexing.
+ *
+ * In Python, if you have a `list` of length 100, `list[-1]` resolves to
+ * `list[99]`, so `resolve_index_in_length_clamped(100, -1)` returns `99`.
+ *
+ * If `length` is 0, 0 is returned for any value of `index`.
+ *
+ * If `index` is out of bounds, clamps the returned value between `0` and
+ * `length - 1` (inclusive).
+ *
+ */
+SliceIndex resolve_index_in_length_clamped(SliceIndex length,
+                                           SliceIndex index) {
+    if (index < 0) {
+        return max<SliceIndex>(length + index, 0);
+    } else {
+        return min<SliceIndex>(length, index);
+    }
+}
+
+const SliceIndex OUT_OF_BOUNDS = -1;
+
+/**
+ * @brief Like `resolve_index_in_length_clamped`, but returns `OUT_OF_BOUNDS`
+ * if `index` is out of bounds.
+ */
+SliceIndex resolve_index_in_length(SliceIndex length, SliceIndex index) {
+    SliceIndex resolved = index < 0 ? length + index : index;
+    if (0 <= resolved && resolved < length) {
+        return resolved;
+    } else {
+        return OUT_OF_BOUNDS;
+    }
+}
+}  // namespace slice
+
+/**
+ * @brief A Python-like slice with **unresolved** indices.
+ */
+struct UserSlice {
+    bool start_defined;
+    SliceIndex start;
+
+    bool stop_defined;
+    SliceIndex stop;
+
+    bool step_defined;
+    SliceIndex step;
+
+    UserSlice() { this->reset(); }
+
+    void reset() {
+        this->start_defined = false;
+        this->stop_defined = false;
+        this->step_defined = false;
+    }
+
+    void set_start(SliceIndex start) {
+        this->start_defined = true;
+        this->start = start;
+    }
+
+    void set_stop(SliceIndex stop) {
+        this->stop_defined = true;
+        this->stop = stop;
+    }
+
+    void set_step(SliceIndex step) {
+        this->step_defined = true;
+        this->step = step;
+    }
+
+    /**
+     * @brief Resolve this slice.
+     *
+     * In Python, this would be `slice(start, stop, step).indices(length)`.
+     *
+     * @return A `Slice` with the resolved indices.
+     */
+    Slice indices(SliceIndex length) {
+        Slice result;
+
+        result.step = step_defined ? step : 1;
+        bool step_is_negative = result.step < 0;
+
+        if (start_defined) {
+            result.start =
+                slice::resolve_index_in_length_clamped(length, start);
+        } else {
+            result.start = step_is_negative ? length - 1 : 0;
+        }
+
+        if (stop_defined) {
+            result.stop = slice::resolve_index_in_length_clamped(length, stop);
+        } else {
+            result.stop = step_is_negative ? -1 : length;
+        }
+
+        return result;
+    }
+
+    /**
+     * @brief Like `.indices()` but with assertions.
+     */
+    void indices_checked(ErrorContext* errctx, SliceIndex length,
+                         Slice* result) {
+        if (length < 0) {
+            errctx->set_exception(errctx->exceptions->value_error,
+                                  "length should not be negative, got {0}",
+                                  length);
+            return;
+        }
+
+        if (this->step_defined && this->step == 0) {
+            errctx->set_exception(errctx->exceptions->value_error,
+                                  "slice step cannot be zero");
+            return;
+        }
+
+        *result = this->indices(length);
+    }
+};
+}  // namespace
--- a/nac3core/irrt/irrt/utils.hpp
+++ b/nac3core/irrt/irrt/utils.hpp
@ -0,0 +1,104 @@
+#pragma once
+
+namespace {
+template <typename T>
+const T& max(const T& a, const T& b) {
+    return a > b ? a : b;
+}
+
+template <typename T>
+const T& min(const T& a, const T& b) {
+    return a > b ? b : a;
+}
+
+/**
+ * @brief Compare contents of two arrays with the same length.
+ */
+template <typename T>
+bool arrays_match(int len, T* as, T* bs) {
+    for (int i = 0; i < len; i++) {
+        if (as[i] != bs[i]) return false;
+    }
+    return true;
+}
+
+namespace cstr_utils {
+/**
+ * @brief Return true if `str` is empty.
+ */
+bool is_empty(const char* str) { return str[0] == '\0'; }
+
+/**
+ * @brief Implementation of `strcmp()`
+ */
+int8_t compare(const char* a, const char* b) {
+    uint32_t i = 0;
+    while (true) {
+        if (a[i] < b[i]) {
+            return -1;
+        } else if (a[i] > b[i]) {
+            return 1;
+        } else {
+            if (a[i] == '\0') {
+                return 0;
+            } else {
+                i++;
+            }
+        }
+    }
+}
+
+/**
+ * @brief Return true two strings have the same content.
+ */
+int8_t equal(const char* a, const char* b) { return compare(a, b) == 0; }
+
+/**
+ * @brief Implementation of `strlen()`.
+ */
+uint32_t length(const char* str) {
+    uint32_t length = 0;
+    while (*str != '\0') {
+        length++;
+        str++;
+    }
+    return length;
+}
+
+/**
+ * @brief Copy a null-terminated string to a buffer with limited size and guaranteed null-termination.
+ *
+ * `dst_max_size` must be greater than 0, otherwise this function has undefined behavior.
+ *
+ * This function attempts to copy everything from `src` from `dst`, and *always* null-terminates `dst`.
+ *
+ * If the size of `dst` is too small, the final byte (`dst[dst_max_size - 1]`) of `dst` will be set to
+ * the null terminator.
+ *
+ * @param src String to copy from.
+ * @param dst Buffer to copy string to.
+ * @param dst_max_size
+ *   Number of bytes of this buffer, including the space needed for the null terminator.
+ *   Must be greater than 0.
+ * @return If `dst` is too small to contain everything in `src`.
+ */
+bool copy(const char* src, char* dst, uint32_t dst_max_size) {
+    for (uint32_t i = 0; i < dst_max_size; i++) {
+        bool is_last = i + 1 == dst_max_size;
+        if (is_last && src[i] != '\0') {
+            dst[i] = '\0';
+            return false;
+        }
+
+        if (src[i] == '\0') {
+            dst[i] = '\0';
+            return true;
+        }
+
+        dst[i] = src[i];
+    }
+
+    __builtin_unreachable();
+}
+}  // namespace cstr_utils
+}  // namespace
--- a/nac3core/irrt/irrt_basic.hpp
+++ b/nac3core/irrt/irrt_basic.hpp
@ -1,216 +0,0 @@
-#pragma once
-
-#include "irrt_utils.hpp"
-#include "irrt_typedefs.hpp"
-
-/*
-    This header contains IRRT implementations
-    that do not deserved to be categorized (e.g., into numpy, etc.)
-
-    Check out other *.hpp files before including them here!!
-*/
-
-// The type of an index or a value describing the length of a range/slice is
-// always `int32_t`.
-
-namespace {
-    // adapted from GNU Scientific Library: https://git.savannah.gnu.org/cgit/gsl.git/tree/sys/pow_int.c
-    // need to make sure `exp >= 0` before calling this function
-    template <typename T>
-    T __nac3_int_exp_impl(T base, T exp) {
-        T res = 1;
-        /* repeated squaring method */
-        do {
-            if (exp & 1) {
-                res *= base; /* for n odd */
-            }
-            exp >>= 1;
-            base *= base;
-        } while (exp);
-        return res;
-    }
-}
-
-extern "C" {
-    #define DEF_nac3_int_exp_(T) \
-        T __nac3_int_exp_##T(T base, T exp) {\
-            return __nac3_int_exp_impl(base, exp);\
-        }
-
-    DEF_nac3_int_exp_(int32_t)
-    DEF_nac3_int_exp_(int64_t)
-    DEF_nac3_int_exp_(uint32_t)
-    DEF_nac3_int_exp_(uint64_t)
-
-    SliceIndex __nac3_slice_index_bound(SliceIndex i, const SliceIndex len) {
-        if (i < 0) {
-            i = len + i;
-        }
-        if (i < 0) {
-            return 0;
-        } else if (i > len) {
-            return len;
-        }
-        return i;
-    }
-
-    SliceIndex __nac3_range_slice_len(
-        const SliceIndex start,
-        const SliceIndex end,
-        const SliceIndex step
-    ) {
-        SliceIndex diff = end - start;
-        if (diff > 0 && step > 0) {
-            return ((diff - 1) / step) + 1;
-        } else if (diff < 0 && step < 0) {
-            return ((diff + 1) / step) + 1;
-        } else {
-            return 0;
-        }
-    }
-
-    // Handle list assignment and dropping part of the list when
-    // both dest_step and src_step are +1.
-    // - All the index must *not* be out-of-bound or negative,
-    // - The end index is *inclusive*,
-    // - The length of src and dest slice size should already
-    // be checked: if dest.step == 1 then len(src) <= len(dest) else len(src) == len(dest)
-    SliceIndex __nac3_list_slice_assign_var_size(
-        SliceIndex dest_start,
-        SliceIndex dest_end,
-        SliceIndex dest_step,
-        uint8_t *dest_arr,
-        SliceIndex dest_arr_len,
-        SliceIndex src_start,
-        SliceIndex src_end,
-        SliceIndex src_step,
-        uint8_t *src_arr,
-        SliceIndex src_arr_len,
-        const SliceIndex size
-    ) {
-        /* if dest_arr_len == 0, do nothing since we do not support extending list */
-        if (dest_arr_len == 0) return dest_arr_len;
-        /* if both step is 1, memmove directly, handle the dropping of the list, and shrink size */
-        if (src_step == dest_step && dest_step == 1) {
-            const SliceIndex src_len = (src_end >= src_start) ? (src_end - src_start + 1) : 0;
-            const SliceIndex dest_len = (dest_end >= dest_start) ? (dest_end - dest_start + 1) : 0;
-            if (src_len > 0) {
-                __builtin_memmove(
-                    dest_arr + dest_start * size,
-                    src_arr + src_start * size,
-                    src_len * size
-                );
-            }
-            if (dest_len > 0) {
-                /* dropping */
-                __builtin_memmove(
-                    dest_arr + (dest_start + src_len) * size,
-                    dest_arr + (dest_end + 1) * size,
-                    (dest_arr_len - dest_end - 1) * size
-                );
-            }
-            /* shrink size */
-            return dest_arr_len - (dest_len - src_len);
-        }
-        /* if two range overlaps, need alloca */
-        uint8_t need_alloca =
-            (dest_arr == src_arr)
-            && !(
-                max(dest_start, dest_end) < min(src_start, src_end)
-                || max(src_start, src_end) < min(dest_start, dest_end)
-            );
-        if (need_alloca) {
-            uint8_t *tmp = reinterpret_cast<uint8_t *>(__builtin_alloca(src_arr_len * size));
-            __builtin_memcpy(tmp, src_arr, src_arr_len * size);
-            src_arr = tmp;
-        }
-        SliceIndex src_ind = src_start;
-        SliceIndex dest_ind = dest_start;
-        for (;
-            (src_step > 0) ? (src_ind <= src_end) : (src_ind >= src_end);
-            src_ind += src_step, dest_ind += dest_step
-        ) {
-            /* for constant optimization */
-            if (size == 1) {
-                __builtin_memcpy(dest_arr + dest_ind, src_arr + src_ind, 1);
-            } else if (size == 4) {
-                __builtin_memcpy(dest_arr + dest_ind * 4, src_arr + src_ind * 4, 4);
-            } else if (size == 8) {
-                __builtin_memcpy(dest_arr + dest_ind * 8, src_arr + src_ind * 8, 8);
-            } else {
-                /* memcpy for var size, cannot overlap after previous alloca */
-                __builtin_memcpy(dest_arr + dest_ind * size, src_arr + src_ind * size, size);
-            }
-        }
-        /* only dest_step == 1 can we shrink the dest list. */
-        /* size should be ensured prior to calling this function */
-        if (dest_step == 1 && dest_end >= dest_start) {
-            __builtin_memmove(
-                dest_arr + dest_ind * size,
-                dest_arr + (dest_end + 1) * size,
-                (dest_arr_len - dest_end - 1) * size
-            );
-            return dest_arr_len - (dest_end - dest_ind) - 1;
-        }
-        return dest_arr_len;
-    }
-
-    int32_t __nac3_isinf(double x) {
-        return __builtin_isinf(x);
-    }
-
-    int32_t __nac3_isnan(double x) {
-        return __builtin_isnan(x);
-    }
-
-    double tgamma(double arg);
-
-    double __nac3_gamma(double z) {
-        // Handling for denormals
-        //     | x                 | Python gamma(x) | C tgamma(x) |
-        // --- | ----------------- | --------------- | ----------- |
-        // (1) | nan               | nan             | nan         |
-        // (2) | -inf              | -inf            | inf         |
-        // (3) | inf               | inf             | inf         |
-        // (4) | 0.0               | inf             | inf         |
-        // (5) | {-1.0, -2.0, ...} | inf             | nan         |
-
-        // (1)-(3)
-        if (__builtin_isinf(z) || __builtin_isnan(z)) {
-            return z;
-        }
-
-        double v = tgamma(z);
-
-        // (4)-(5)
-        return __builtin_isinf(v) || __builtin_isnan(v) ? __builtin_inf() : v;
-    }
-
-    double lgamma(double arg);
-
-    double __nac3_gammaln(double x) {
-        // libm's handling of value overflows differs from scipy:
-        // - scipy: gammaln(-inf) -> -inf
-        // - libm : lgamma(-inf) -> inf
-
-        if (__builtin_isinf(x)) {
-            return x;
-        }
-
-        return lgamma(x);
-    }
-
-    double j0(double x);
-
-    double __nac3_j0(double x) {
-        // libm's handling of value overflows differs from scipy:
-        // - scipy: j0(inf) -> nan
-        // - libm : j0(inf) -> 0.0
-
-        if (__builtin_isinf(x)) {
-            return __builtin_nan("");
-        }
-
-        return j0(x);
-    }
-}
--- a/nac3core/irrt/irrt_everything.hpp
+++ b/nac3core/irrt/irrt_everything.hpp
@ -1,14 +1,13 @@
 #pragma once

-#include "irrt_utils.hpp"
-#include "irrt_typedefs.hpp"
-#include "irrt_basic.hpp"
-#include "irrt_slice.hpp"
-#include "irrt_numpy_ndarray.hpp"
-
-/*
-    All IRRT implementations.
-
-    We don't have any pre-compiled objects, so we are writing all implementations in headers and
-    concatenate them with `#include` into one massive source file that contains all the IRRT stuff.
-*/
+#include <irrt/artiq_defs.hpp>
+#include <irrt/core.hpp>
+#include <irrt/error_context.hpp>
+#include <irrt/int_defs.hpp>
+#include <irrt/ndarray/basic.hpp>
+#include <irrt/ndarray/broadcast.hpp>
+#include <irrt/ndarray/def.hpp>
+#include <irrt/ndarray/indexing.hpp>
+#include <irrt/ndarray/reshape.hpp>
+#include <irrt/slice.hpp>
+#include <irrt/utils.hpp>
--- a/nac3core/irrt/irrt_numpy_ndarray.hpp
+++ b/nac3core/irrt/irrt_numpy_ndarray.hpp
@ -1,466 +0,0 @@
-#pragma once
-
-#include "irrt_utils.hpp"
-#include "irrt_typedefs.hpp"
-#include "irrt_slice.hpp"
-
-/*
-    NDArray-related implementations.
-`*/
-
-// NDArray indices are always `uint32_t`.
-using NDIndex = uint32_t;
-
-namespace {
-    namespace ndarray_util {
-        template <typename SizeT>
-        static void set_indices_by_nth(SizeT ndims, const SizeT* shape, SizeT* indices, SizeT nth) {
-            for (int32_t i = 0; i < ndims; i++) {
-                int32_t dim_i = ndims - i - 1;
-                int32_t dim = shape[dim_i];
-
-                indices[dim_i] = nth % dim;
-                nth /= dim;
-            }
-        }
-
-        // Compute the strides of an ndarray given an ndarray `shape`
-        // and assuming that the ndarray is *fully C-contagious*.
-        //
-        // You might want to read up on https://ajcr.net/stride-guide-part-1/.
-        template <typename SizeT>
-        static void set_strides_by_shape(SizeT itemsize, SizeT ndims, SizeT* dst_strides, const SizeT* shape) {
-            SizeT stride_product = 1;
-            for (SizeT i = 0; i < ndims; i++) {
-                int dim_i = ndims - i - 1;
-                dst_strides[dim_i] = stride_product * itemsize;
-                stride_product *= shape[dim_i];
-            }
-        }
-
-        // Compute the size/# of elements of an ndarray given its shape
-        template <typename SizeT>
-        static SizeT calc_size_from_shape(SizeT ndims, const SizeT* shape) {
-            SizeT size = 1;
-            for (SizeT dim_i = 0; dim_i < ndims; dim_i++) size *= shape[dim_i];
-            return size;
-        }
-
-        template <typename SizeT>
-        static bool can_broadcast_shape_to(
-            const SizeT target_ndims,
-            const SizeT *target_shape,
-            const SizeT src_ndims,
-            const SizeT *src_shape
-        ) {
-            /*
-                // See https://numpy.org/doc/stable/user/basics.broadcasting.html
-
-                This function handles this example:
-                ```
-                Image  (3d array): 256 x 256 x 3
-                Scale  (1d array):             3
-                Result (3d array): 256 x 256 x 3
-                ```
-
-                Other interesting examples to consider:
-                - `can_broadcast_shape_to([3], [1, 1, 1, 1, 3]) == true`
-                - `can_broadcast_shape_to([3], [3, 1]) == false`
-                - `can_broadcast_shape_to([256, 256, 3], [256, 1, 3]) == true`
-
-                In cases when the shapes contain zero(es):
-                - `can_broadcast_shape_to([0], [1]) == true`
-                - `can_broadcast_shape_to([0], [2]) == false`
-                - `can_broadcast_shape_to([0, 4, 0, 0], [1]) == true`
-                - `can_broadcast_shape_to([0, 4, 0, 0], [1, 1, 1, 1]) == true`
-                - `can_broadcast_shape_to([0, 4, 0, 0], [1, 4, 1, 1]) == true`
-                - `can_broadcast_shape_to([4, 3], [0, 3]) == false`
-                - `can_broadcast_shape_to([4, 3], [0, 0]) == false`
-            */
-
-            // This is essentially doing the following in Python:
-            // `for target_dim, src_dim in itertools.zip_longest(target_shape[::-1], src_shape[::-1], fillvalue=1)`
-            for (SizeT i = 0; i < max(target_ndims, src_ndims); i++) {
-                SizeT target_dim_i = target_ndims - i - 1;
-                SizeT src_dim_i = src_ndims - i - 1;
-
-                bool target_dim_exists = target_dim_i >= 0;
-                bool src_dim_exists = src_dim_i >= 0;
-
-                SizeT target_dim = target_dim_exists ? target_shape[target_dim_i] : 1;
-                SizeT src_dim = src_dim_exists ? src_shape[src_dim_i] : 1;
-
-                bool ok = src_dim == 1 || target_dim == src_dim;
-                if (!ok) return false;
-            }
-
-            return true;
-        }
-    }
-
-    typedef uint8_t NDSliceType;
-    extern "C" {
-        const NDSliceType INPUT_SLICE_TYPE_INDEX = 0;
-        const NDSliceType INPUT_SLICE_TYPE_SLICE = 1;
-    }
-
-    struct NDSlice {
-        // A poor-man's `std::variant<int, UserRange>`
-        NDSliceType type;
-
-        /*
-            if type == INPUT_SLICE_TYPE_INDEX => `slice` points to a single `SizeT`
-            if type == INPUT_SLICE_TYPE_SLICE => `slice` points to a single `UserRange`
-        */
-        uint8_t *slice;
-    };
-
-    namespace ndarray_util {
-        template<typename SizeT>
-        SizeT deduce_ndims_after_slicing(SizeT ndims, SizeT num_slices, const NDSlice *slices) {
-            irrt_assert(num_slices <= ndims);
-
-            SizeT final_ndims = ndims;
-            for (SizeT i = 0; i < num_slices; i++) {
-                if (slices[i].type == INPUT_SLICE_TYPE_INDEX) {
-                    final_ndims--; // An integer slice demotes the rank by 1
-                }
-            }
-            return final_ndims;
-        }
-    }
-
-    template <typename SizeT>
-    struct NDArrayIndicesIter {
-        SizeT ndims;
-        const SizeT *shape;
-        SizeT *indices;
-
-        void set_indices_zero() {
-            __builtin_memset(indices, 0, sizeof(SizeT) * ndims);
-        }
-
-        void next() {
-            for (SizeT i = 0; i < ndims; i++) {
-                SizeT dim_i = ndims - i - 1;
-
-                indices[dim_i]++;
-                if (indices[dim_i] < shape[dim_i]) {
-                    break;
-                } else {
-                    indices[dim_i] = 0;
-                }
-            }
-        }
-    };
-
-    // The NDArray object. `SizeT` is the *signed* size type of this ndarray.
-    //
-    // NOTE: The order of fields is IMPORTANT. DON'T TOUCH IT
-    //
-    // Some resources you might find helpful:
-    // - The official numpy implementations:
-    //   - https://github.com/numpy/numpy/blob/735a477f0bc2b5b84d0e72d92f224bde78d4e069/doc/source/reference/c-api/types-and-structures.rst
-    // - On strides (about reshaping, slicing, C-contagiousness, etc)
-    //   - https://ajcr.net/stride-guide-part-1/.
-    //   - https://ajcr.net/stride-guide-part-2/.
-    //   - https://ajcr.net/stride-guide-part-3/.
-    template <typename SizeT>
-    struct NDArray {
-        // The underlying data this `ndarray` is pointing to.
-        //
-        // NOTE: Formally this should be of type `void *`, but clang
-        // translates `void *` to `i8 *` when run with `-S -emit-llvm`,
-        // so we will put `uint8_t *` here for clarity.
-        uint8_t *data;
-
-        // The number of bytes of a single element in `data`.
-        //
-        // The `SizeT` is treated as `unsigned`.
-        SizeT itemsize;
-
-        // The number of dimensions of this shape.
-        //
-        // The `SizeT` is treated as `unsigned`.
-        SizeT ndims;
-
-        // Array shape, with length equal to `ndims`.
-        //
-        // The `SizeT` is treated as `unsigned`.
-        //
-        // NOTE: `shape` can contain 0.
-        //   (those appear when the user makes an out of bounds slice into an ndarray, e.g., `np.zeros((3, 3))[400:].shape == (0, 3)`)
-        SizeT *shape;
-
-        // Array strides (stride value is in number of bytes, NOT number of elements), with length equal to `ndims`.
-        //
-        // The `SizeT` is treated as `signed`.
-        //
-        // NOTE: `strides` can have negative numbers.
-        //   (those appear when there is a slice with a negative step, e.g., `my_array[::-1]`)
-        SizeT *strides;
-
-        // Calculate the size/# of elements of an `ndarray`.
-        // This function corresponds to `np.size(<ndarray>)` or `ndarray.size`
-        SizeT size() {
-            return ndarray_util::calc_size_from_shape(ndims, shape);
-        }
-
-        // Calculate the number of bytes of its content of an `ndarray` *in its view*.
-        // This function corresponds to `ndarray.nbytes`
-        SizeT nbytes() {
-            return this->size() * itemsize;
-        }
-
-        void set_value_at_pelement(uint8_t* pelement, const uint8_t* pvalue) {
-            __builtin_memcpy(pelement, pvalue, itemsize);
-        }
-
-        uint8_t* get_pelement(const SizeT *indices) {
-            uint8_t* element = data;
-            for (SizeT dim_i = 0; dim_i < ndims; dim_i++)
-                element += indices[dim_i] * strides[dim_i];
-            return element;
-        }
-
-        uint8_t* get_nth_pelement(SizeT nth) {
-            irrt_assert(0 <= nth);
-            irrt_assert(nth < this->size());
-
-            SizeT* indices = (SizeT*) __builtin_alloca(sizeof(SizeT) * this->ndims);
-            ndarray_util::set_indices_by_nth(this->ndims, this->shape, indices, nth);
-            return get_pelement(indices);
-        }
-
-        // Get pointer to the first element of this ndarray, assuming
-        // `this->size() > 0`, i.e., not "degenerate" due to zeroes in `this->shape`)
-        //
-        // This is particularly useful for when the ndarray is just containing a single scalar.
-        uint8_t* get_first_pelement() {
-            irrt_assert(this->size() > 0);
-            return this->data; // ...It is simply `this->data`
-        }
-
-        // Is the given `indices` valid/in-bounds?
-        bool in_bounds(const SizeT *indices) {
-            for (SizeT dim_i = 0; dim_i < ndims; dim_i++) {
-                bool dim_ok = indices[dim_i] < shape[dim_i];
-                if (!dim_ok) return false;
-            }
-            return true;
-        }
-
-        // Fill the ndarray with a value
-        void fill_generic(const uint8_t* pvalue) {
-            NDArrayIndicesIter<SizeT> iter;
-            iter.ndims = this->ndims;
-            iter.shape = this->shape;
-            iter.indices = (SizeT*) __builtin_alloca(sizeof(SizeT) * ndims);
-            iter.set_indices_zero();
-
-            for (SizeT i = 0; i < this->size(); i++, iter.next()) {
-                uint8_t* pelement = get_pelement(iter.indices);
-                set_value_at_pelement(pelement, pvalue);
-            }
-        }
-
-        // Set the strides of the ndarray with `ndarray_util::set_strides_by_shape`
-        void set_strides_by_shape() {
-            ndarray_util::set_strides_by_shape(itemsize, ndims, strides, shape);
-        }
-
-        // https://numpy.org/doc/stable/reference/generated/numpy.eye.html
-        void set_to_eye(SizeT k, const uint8_t* zero_pvalue, const uint8_t* one_pvalue) {
-            __builtin_assume(ndims == 2);
-
-            // TODO: Better implementation
-
-            fill_generic(zero_pvalue);
-            for (SizeT i = 0; i < min(shape[0], shape[1]); i++) {
-                SizeT row = i;
-                SizeT col = i + k;
-                SizeT indices[2] = { row, col };
-
-                if (!in_bounds(indices)) continue;
-
-                uint8_t* pelement = get_pelement(indices);
-                set_value_at_pelement(pelement, one_pvalue);
-            }
-        }
-
-        // To support numpy complex slices (e.g., `my_array[:50:2,4,:2:-1]`)
-        //
-        // Things assumed by this function:
-        // - `dst_ndarray` is allocated by the caller
-        // - `dst_ndarray.ndims` has the correct value (according to `ndarray_util::deduce_ndims_after_slicing`).
-        //   - ... and `dst_ndarray.shape` and `dst_ndarray.strides` have been allocated by the caller as well
-        //
-        // Other notes:
-        // - `dst_ndarray->data` does not have to be set, it will be derived.
-        // - `dst_ndarray->itemsize` does not have to be set, it will be set to `this->itemsize`
-        // - `dst_ndarray->shape` and `dst_ndarray.strides` can contain empty values
-        void slice(SizeT num_ndslices, NDSlice* ndslices, NDArray<SizeT>* dst_ndarray) {
-            // REFERENCE CODE (check out `_index_helper` in `__getitem__`):
-            //   https://github.com/wadetb/tinynumpy/blob/0d23d22e07062ffab2afa287374c7b366eebdda1/tinynumpy/tinynumpy.py#L652
-
-            irrt_assert(dst_ndarray->ndims == ndarray_util::deduce_ndims_after_slicing(this->ndims, num_ndslices, ndslices));
-
-            dst_ndarray->data = this->data;
-
-            SizeT this_axis = 0;
-            SizeT dst_axis = 0;
-
-            for (SizeT i = 0; i < num_ndslices; i++) {
-                NDSlice *ndslice = &ndslices[i];
-                if (ndslice->type == INPUT_SLICE_TYPE_INDEX) {
-                    // Handle when the ndslice is just a single (possibly negative) integer
-                    // e.g., `my_array[::2, -5, ::-1]`
-                    //                      ^^------ like this
-                    SizeT index_user = *((SizeT*) ndslice->slice);
-                    SizeT index = resolve_index_in_length(this->shape[this_axis], index_user);
-                    dst_ndarray->data += index * this->strides[this_axis]; // Add offset
-
-                    // Next
-                    this_axis++;
-                } else if (ndslice->type == INPUT_SLICE_TYPE_SLICE) {
-                    // Handle when the ndslice is a slice (represented by UserSlice in IRRT)
-                    // e.g., `my_array[::2, -5, ::-1]`
-                    //                 ^^^------^^^^----- like these
-                    UserSlice<SizeT>* user_slice = (UserSlice<SizeT>*) ndslice->slice;
-                    Slice<SizeT> slice = user_slice->indices(this->shape[this_axis]); // To resolve negative indices and other funny stuff written by the user
-
-                    // NOTE: There is no need to write special code to handle negative steps/strides.
-                    // This simple implementation meticulously handles both positive and negative steps/strides.
-                    // Check out the tinynumpy and IRRT's test cases if you are not convinced.
-                    dst_ndarray->data += slice.start * this->strides[this_axis]; // Add offset (NOTE: no need to `* itemsize`, strides count in # of bytes)
-                    dst_ndarray->strides[dst_axis] = slice.step * this->strides[this_axis]; // Determine stride
-                    dst_ndarray->shape[dst_axis] = slice.len(); // Determine shape dimension
-
-                    // Next
-                    dst_axis++;
-                    this_axis++;
-                } else {
-                    __builtin_unreachable();
-                }
-            }
-
-            irrt_assert(dst_axis == dst_ndarray->ndims); // Sanity check on the implementation
-        }
-
-        // Similar to `np.broadcast_to(<ndarray>, <target_shape>)`
-        // Assumptions:
-        //   - `this` has to be fully initialized.
-        //   - `dst_ndarray->ndims` has to be set.
-        //   - `dst_ndarray->shape` has to be set, this determines the shape `this` broadcasts to.
-        //
-        // Other notes:
-        //   - `dst_ndarray->data` does not have to be set, it will be set to `this->data`.
-        //   - `dst_ndarray->itemsize` does not have to be set, it will be set to `this->data`.
-        //   - `dst_ndarray->strides` does not have to be set, it will be overwritten.
-        //
-        // Cautions:
-        //   ```
-        //   xs = np.zeros((4,))
-        //   ys = np.zero((4, 1))
-        //   ys[:] = xs # ok
-        // 
-        //   xs = np.zeros((1, 4))
-        //   ys = np.zero((4,))
-        //   ys[:] = xs # allowed
-        //   # However `np.broadcast_to(xs, (4,))` would fails, as per numpy's broadcasting rule.
-        //   # and apparently numpy will "deprecate" this? SEE https://github.com/numpy/numpy/issues/21744
-        //   # This implementation will NOT support this assignment.
-        //   ```
-        void broadcast_to(NDArray<SizeT>* dst_ndarray) {
-            dst_ndarray->data = this->data;
-            dst_ndarray->itemsize = this->itemsize;
-
-            irrt_assert(
-                ndarray_util::can_broadcast_shape_to(
-                    dst_ndarray->ndims,
-                    dst_ndarray->shape,
-                    this->ndims,
-                    this->shape
-                )
-            );
-
-            SizeT stride_product = 1;
-            for (SizeT i = 0; i < max(this->ndims, dst_ndarray->ndims); i++) {
-                SizeT this_dim_i = this->ndims - i - 1;
-                SizeT dst_dim_i = dst_ndarray->ndims - i - 1;
-
-                bool this_dim_exists = this_dim_i >= 0;
-                bool dst_dim_exists = dst_dim_i >= 0;
-
-                // TODO: Explain how this works
-                bool c1 = this_dim_exists && this->shape[this_dim_i] == 1;
-                bool c2 = dst_dim_exists && dst_ndarray->shape[dst_dim_i] != 1;
-                if (!this_dim_exists || (c1 && c2)) {
-                    dst_ndarray->strides[dst_dim_i] = 0; // Freeze it in-place
-                } else {
-                    dst_ndarray->strides[dst_dim_i] = stride_product * this->itemsize;
-                    stride_product *= this->shape[this_dim_i]; // NOTE: this_dim_exist must be true here.
-                }
-            }
-        }
-
-        // Simulates `this_ndarray[:] = src_ndarray`, with automatic broadcasting.
-        // Caution on https://github.com/numpy/numpy/issues/21744
-        // Also see `NDArray::broadcast_to`
-        void assign_with(NDArray<SizeT>* src_ndarray) {
-            irrt_assert(
-                ndarray_util::can_broadcast_shape_to(
-                    this->ndims,
-                    this->shape,
-                    src_ndarray->ndims,
-                    src_ndarray->shape
-                )
-            );
-
-            // Broadcast the `src_ndarray` to make the reading process *much* easier
-            SizeT* broadcasted_src_ndarray_strides = __builtin_alloca(sizeof(SizeT) * this->ndims); // Remember to allocate strides beforehand
-            NDArray<SizeT> broadcasted_src_ndarray = {
-                .ndims = this->ndims,
-                .shape = this->shape,
-                .strides = broadcasted_src_ndarray_strides
-            };
-            src_ndarray->broadcast_to(&broadcasted_src_ndarray);
-
-            // Using iter instead of `get_nth_pelement` because it is slightly faster
-            SizeT* indices = __builtin_alloca(sizeof(SizeT) * this->ndims);
-            auto iter = NDArrayIndicesIter<SizeT> {
-                .ndims = this->ndims,
-                .shape = this->shape,
-                .indices = indices
-            };
-            const SizeT this_size = this->size();
-            for (SizeT i = 0; i < this_size; i++, iter.next()) {
-                uint8_t* src_pelement = broadcasted_src_ndarray_strides->get_pelement(indices);
-                uint8_t* this_pelement = this->get_pelement(indices);
-                this->set_value_at_pelement(src_pelement, src_pelement);
-            }
-        }
-    };
-}
-
-extern "C" {
-    uint32_t __nac3_ndarray_size(NDArray<int32_t>* ndarray) {
-        return ndarray->size();
-    }
-
-    uint64_t __nac3_ndarray_size64(NDArray<int64_t>* ndarray) {
-        return ndarray->size();
-    }
-
-    void __nac3_ndarray_fill_generic(NDArray<int32_t>* ndarray, uint8_t* pvalue) {
-        ndarray->fill_generic(pvalue);
-    }
-
-    void __nac3_ndarray_fill_generic64(NDArray<int64_t>* ndarray, uint8_t* pvalue) {
-        ndarray->fill_generic(pvalue);
-    }
-
-    // void __nac3_ndarray_slice(NDArray<int32_t>* ndarray, int32_t num_slices, NDSlice<int32_t> *slices, NDArray<int32_t> *dst_ndarray) {
-    //     // ndarray->slice(num_slices, slices, dst_ndarray);
-    // }
-}
--- a/nac3core/irrt/irrt_slice.hpp
+++ b/nac3core/irrt/irrt_slice.hpp
@ -1,80 +0,0 @@
-#pragma once
-
-#include "irrt_utils.hpp"
-#include "irrt_typedefs.hpp"
-
-namespace {
-    // A proper slice in IRRT, all negative indices have be resolved to absolute values.
-    // Even though nac3core's slices are always `int32_t`, we will template slice anyway
-    // since this struct is used as a general utility.
-    template <typename T>
-    struct Slice {
-        T start;
-        T stop;
-        T step;
-
-        // The length/The number of elements of the slice if it were a range,
-        // i.e., the value of `len(range(this->start, this->stop, this->end))`
-        T len() {
-            T diff = stop - start;
-            if (diff > 0 && step > 0) {
-                return ((diff - 1) / step) + 1;
-            } else if (diff < 0 && step < 0) {
-                return ((diff + 1) / step) + 1;
-            } else {
-                return 0;
-            }
-        }
-    };
-
-    template<typename T>
-    T resolve_index_in_length(T length, T index) {
-        irrt_assert(length >= 0);
-        if (index < 0) {
-            // Remember that index is negative, so do a plus here
-            return max(length + index, 0);
-        } else {
-            return min(length, index);
-        }
-    }
-
-    // NOTE: using a bitfield for the `*_defined` is better, at the
-    // cost of a more annoying implementation in nac3core inkwell
-    template <typename T>
-    struct UserSlice {
-        uint8_t start_defined;
-        T start;
-
-        uint8_t stop_defined;
-        T stop;
-
-        uint8_t step_defined;
-        T step;
-
-        // Like Python's `slice(start, stop, step).indices(length)`
-        Slice<T> indices(T length) {
-            // NOTE: This function implements Python's `slice.indices` *FAITHFULLY*.
-            // SEE: https://github.com/python/cpython/blob/f62161837e68c1c77961435f1b954412dd5c2b65/Objects/sliceobject.c#L546
-            irrt_assert(length >= 0);
-            irrt_assert(!step_defined || step != 0); // step_defined -> step != 0; step cannot be zero if specified by user
-
-            Slice<T> result;
-            result.step = step_defined ? step : 1;
-            bool step_is_negative = result.step < 0;
-
-            if (start_defined) {
-                result.start = resolve_index_in_length(length, start);
-            } else {
-                result.start = step_is_negative ? length - 1 : 0;
-            }
-            
-            if (stop_defined) {
-                result.stop = resolve_index_in_length(length, stop);
-            } else {
-                result.stop = step_is_negative ? -1 : length;
-            }
-
-            return result;
-        }
-    };
-}
--- a/nac3core/irrt/irrt_test.cpp
+++ b/nac3core/irrt/irrt_test.cpp
@ -4,655 +4,17 @@
 #include <cstdint>
 #include <cstdio>
 #include <cstdlib>
-
-// Set `IRRT_DONT_TYPEDEF_INTS` because `cstdint` defines them
-#define IRRT_DONT_TYPEDEF_INTS
-#include "irrt_everything.hpp"
-
-void test_fail() {
-    printf("[!] Test failed\n");
-    exit(1);
-}
-
-void __begin_test(const char* function_name, const char* file, int line) {
-    printf("######### Running %s @ %s:%d\n", function_name, file, line);
-}
-
-#define BEGIN_TEST() __begin_test(__FUNCTION__, __FILE__, __LINE__)
-
-template <typename T>
-void debug_print_array(const char* format, int len, T* as) {
-    printf("[");
-    for (int i = 0; i < len; i++) {
-        if (i != 0) printf(", ");
-        printf(format, as[i]);
-    }
-    printf("]");
-}
-
-template <typename T>
-void assert_arrays_match(const char* label, const char* format, int len, T* expected, T* got) {
-    if (!arrays_match(len, expected, got)) {
-        printf(">>>>>>> %s\n", label);
-        printf("    Expecting = ");
-        debug_print_array(format, len, expected);
-        printf("\n");
-        printf("          Got = ");
-        debug_print_array(format, len, got);
-        printf("\n");
-        test_fail();
-    }
-}
-
-template <typename T>
-void assert_values_match(const char* label, const char* format, T expected, T got) {
-    if (expected != got) {
-        printf(">>>>>>> %s\n", label);
-        printf("    Expecting = ");
-        printf(format, expected);
-        printf("\n");
-        printf("          Got = ");
-        printf(format, got);
-        printf("\n");
-        test_fail();
-    }
-}
-
-void print_repeated(const char *str, int count) {
-    for (int i = 0; i < count; i++) {
-        printf("%s", str);
-    }
-}
-
-template<typename SizeT, typename ElementT>
-void __print_ndarray_aux(const char *format, bool first, bool last, SizeT* cursor, SizeT depth, NDArray<SizeT>* ndarray) {
-    // A really lazy recursive implementation
-    
-    // Add left padding unless its the first entry (since there would be "[[[" before it)
-    if (!first) {
-        print_repeated(" ", depth);
-    }
-
-    const SizeT dim = ndarray->shape[depth];
-    if (depth + 1 == ndarray->ndims) {
-        // Recursed down to last dimension, print the values in a nice list
-        printf("[");
-
-        SizeT* indices = (SizeT*) __builtin_alloca(sizeof(SizeT) * ndarray->ndims);
-        for (SizeT i = 0; i < dim; i++) {
-            ndarray_util::set_indices_by_nth(ndarray->ndims, ndarray->shape, indices, *cursor);
-            ElementT* pelement = (ElementT*) ndarray->get_pelement(indices);
-            ElementT element = *pelement;
-
-            if (i != 0) printf(", "); // List delimiter
-            printf(format, element);
-            printf("(@");
-            debug_print_array("%d", ndarray->ndims, indices);
-            printf(")");
-
-            (*cursor)++;
-        }
-        printf("]");
-    } else {
-        printf("[");
-        for (SizeT i = 0; i < ndarray->shape[depth]; i++) {
-            __print_ndarray_aux<SizeT, ElementT>(
-                format,
-                i == 0, // first?
-                i + 1 == dim, // last?
-                cursor,
-                depth + 1,
-                ndarray
-            );
-        }
-        printf("]");
-    }
-
-    // Add newline unless its the last entry (since there will be "]]]" after it)
-    if (!last) {
-        print_repeated("\n", depth);
-    }
-}
-
-template<typename SizeT, typename ElementT>
-void print_ndarray(const char *format, NDArray<SizeT>* ndarray) {
-    if (ndarray->ndims == 0) {
-        printf("<empty ndarray>");
-    } else {
-        SizeT cursor = 0;
-        __print_ndarray_aux<SizeT, ElementT>(format, true, true, &cursor, 0, ndarray);
-    }
-    printf("\n");
-}
-
-void test_calc_size_from_shape_normal() {
-    // Test shapes with normal values
-    BEGIN_TEST();
-
-    int32_t shape[4] = { 2, 3, 5, 7 };
-    assert_values_match("size", "%d", 210, ndarray_util::calc_size_from_shape<int32_t>(4, shape));
-}
-
-void test_calc_size_from_shape_has_zero() {
-    // Test shapes with 0 in them
-    BEGIN_TEST();
-
-    int32_t shape[4] = { 2, 0, 5, 7 };
-    assert_values_match("size", "%d", 0, ndarray_util::calc_size_from_shape<int32_t>(4, shape));
-}
-
-void test_set_strides_by_shape() {
-    // Test `set_strides_by_shape()`
-    BEGIN_TEST();
-
-    int32_t shape[4] = { 99, 3, 5, 7 };
-    int32_t strides[4] = { 0 };
-    ndarray_util::set_strides_by_shape((int32_t) sizeof(int32_t), 4, strides, shape);
-
-    int32_t expected_strides[4] = {
-        105 * sizeof(int32_t),
-        35 * sizeof(int32_t),
-        7 * sizeof(int32_t),
-        1 * sizeof(int32_t)
-    };
-    assert_arrays_match("strides", "%u", 4u, expected_strides, strides);
-}
-
-void test_ndarray_indices_iter_normal() {
-    // Test NDArrayIndicesIter normal behavior
-    BEGIN_TEST();
-
-    int32_t shape[3] = { 1, 2, 3 };
-    int32_t indices[3] = { 0, 0, 0 };
-    auto iter = NDArrayIndicesIter<int32_t> {
-        .ndims = 3,
-        .shape = shape,
-        .indices = indices
-    };
-
-    assert_arrays_match("indices #0", "%u", 3u, iter.indices, (int32_t[3]) { 0, 0, 0 });
-    iter.next();
-    assert_arrays_match("indices #1", "%u", 3u, iter.indices, (int32_t[3]) { 0, 0, 1 });
-    iter.next();
-    assert_arrays_match("indices #2", "%u", 3u, iter.indices, (int32_t[3]) { 0, 0, 2 });
-    iter.next();
-    assert_arrays_match("indices #3", "%u", 3u, iter.indices, (int32_t[3]) { 0, 1, 0 });
-    iter.next();
-    assert_arrays_match("indices #4", "%u", 3u, iter.indices, (int32_t[3]) { 0, 1, 1 });
-    iter.next();
-    assert_arrays_match("indices #5", "%u", 3u, iter.indices, (int32_t[3]) { 0, 1, 2 });
-    iter.next();
-    assert_arrays_match("indices #6", "%u", 3u, iter.indices, (int32_t[3]) { 0, 0, 0 }); // Loops back
-    iter.next();
-    assert_arrays_match("indices #7", "%u", 3u, iter.indices, (int32_t[3]) { 0, 0, 1 });
-}
-
-void test_ndarray_fill_generic() {
-    // Test ndarray fill_generic
-    BEGIN_TEST();
-
-    // Choose a type that's neither int32_t nor uint64_t (candidates of SizeT) to spice it up
-    // Also make all the octets non-zero, to see if `memcpy` in `fill_generic` is working perfectly.
-    uint16_t fill_value = 0xFACE;
-
-    uint16_t in_data[6] = { 100, 101, 102, 103, 104, 105 }; // Fill `data` with values that != `999`
-    int32_t in_itemsize = sizeof(uint16_t);
-    const int32_t in_ndims = 2;
-    int32_t in_shape[in_ndims] = { 2, 3 };
-    int32_t in_strides[in_ndims] = {};
-    NDArray<int32_t> ndarray = {
-        .data = (uint8_t*) in_data,
-        .itemsize = in_itemsize,
-        .ndims = in_ndims,
-        .shape = in_shape,
-        .strides = in_strides,
-    };
-    ndarray.set_strides_by_shape();
-    ndarray.fill_generic((uint8_t*) &fill_value); // `fill_generic` here
-
-    uint16_t expected_data[6] = { fill_value, fill_value, fill_value, fill_value, fill_value, fill_value };
-    assert_arrays_match("data", "0x%hX", 6, expected_data, in_data);
-}
-
-void test_ndarray_set_to_eye() {
-    // Test `set_to_eye` behavior (helper function to implement `np.eye()`)
-    BEGIN_TEST();
-
-    double in_data[9] = { 99.0, 99.0, 99.0, 99.0, 99.0, 99.0, 99.0, 99.0, 99.0 };
-    int32_t in_itemsize = sizeof(double);
-    const int32_t in_ndims = 2;
-    int32_t in_shape[in_ndims] = { 3, 3 };
-    int32_t in_strides[in_ndims] = {};
-    NDArray<int32_t> ndarray = {
-        .data = (uint8_t*) in_data,
-        .itemsize = in_itemsize,
-        .ndims = in_ndims,
-        .shape = in_shape,
-        .strides = in_strides,
-    };
-    ndarray.set_strides_by_shape();
-
-    double zero = 0.0;
-    double one = 1.0;
-    ndarray.set_to_eye(1, (uint8_t*) &zero, (uint8_t*) &one);
-
-    assert_values_match("in_data[0]", "%f", 0.0, in_data[0]);
-    assert_values_match("in_data[1]", "%f", 1.0, in_data[1]);
-    assert_values_match("in_data[2]", "%f", 0.0, in_data[2]);
-    assert_values_match("in_data[3]", "%f", 0.0, in_data[3]);
-    assert_values_match("in_data[4]", "%f", 0.0, in_data[4]);
-    assert_values_match("in_data[5]", "%f", 1.0, in_data[5]);
-    assert_values_match("in_data[6]", "%f", 0.0, in_data[6]);
-    assert_values_match("in_data[7]", "%f", 0.0, in_data[7]);
-    assert_values_match("in_data[8]", "%f", 0.0, in_data[8]);
-}
-
-void test_slice_1() {
-    // Test `slice(5, None, None).indices(100) == slice(5, 100, 1)`
-    BEGIN_TEST();
-
-    UserSlice<int> user_slice = {
-        .start_defined = 1,
-        .start = 5,
-        .stop_defined = 0,
-        .step_defined = 0,
-    };
-
-    auto slice = user_slice.indices(100);
-    assert_values_match("start", "%d", 5, slice.start);
-    assert_values_match("stop", "%d", 100, slice.stop);
-    assert_values_match("step", "%d", 1, slice.step);
-}
-
-void test_slice_2() {
-    // Test `slice(400, 999, None).indices(100) == slice(100, 100, 1)`
-    BEGIN_TEST();
-
-    UserSlice<int> user_slice = {
-        .start_defined = 1,
-        .start = 400,
-        .stop_defined = 0,
-        .step_defined = 0,
-    };
-
-    auto slice = user_slice.indices(100);
-    assert_values_match("start", "%d", 100, slice.start);
-    assert_values_match("stop", "%d", 100, slice.stop);
-    assert_values_match("step", "%d", 1, slice.step);
-}
-
-void test_slice_3() {
-    // Test `slice(-10, -5, None).indices(100) == slice(90, 95, 1)`
-    BEGIN_TEST();
-
-    UserSlice<int> user_slice = {
-        .start_defined = 1,
-        .start = -10,
-        .stop_defined = 1,
-        .stop = -5,
-        .step_defined = 0,
-    };
-
-    auto slice = user_slice.indices(100);
-    assert_values_match("start", "%d", 90, slice.start);
-    assert_values_match("stop", "%d", 95, slice.stop);
-    assert_values_match("step", "%d", 1, slice.step);
-}
-
-void test_slice_4() {
-    // Test `slice(None, None, -5).indices(100) == (99, -1, -5)`
-    BEGIN_TEST();
-
-    UserSlice<int> user_slice = {
-        .start_defined = 0,
-        .stop_defined = 0,
-        .step_defined = 1,
-        .step = -5
-    };
-
-    auto slice = user_slice.indices(100);
-    assert_values_match("start", "%d", 99, slice.start);
-    assert_values_match("stop", "%d", -1, slice.stop);
-    assert_values_match("step", "%d", -5, slice.step);
-}
-
-void test_ndslice_1() {
-    /*
-        Reference Python code:
-        ```python
-        ndarray = np.arange(12, dtype=np.float64).reshape((3, 4));
-        # array([[ 0.,  1.,  2.,  3.],
-        #        [ 4.,  5.,  6.,  7.],
-        #        [ 8.,  9., 10., 11.]])
-
-        dst_ndarray = ndarray[-2:, 1::2]
-        # array([[ 5.,  7.],
-        #        [ 9., 11.]])
-
-        assert dst_ndarray.shape == (2, 2)
-        assert dst_ndarray.strides == (32, 16)
-        assert dst_ndarray[0, 0] == 5.0
-        assert dst_ndarray[0, 1] == 7.0
-        assert dst_ndarray[1, 0] == 9.0
-        assert dst_ndarray[1, 1] == 11.0
-        ```
-    */
-    BEGIN_TEST();
-
-    double in_data[12] = { 0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0 };
-    int32_t in_itemsize = sizeof(double);
-    const int32_t in_ndims = 2;
-    int32_t in_shape[in_ndims] = { 3, 4 };
-    int32_t in_strides[in_ndims] = {};
-    NDArray<int32_t> ndarray = {
-        .data = (uint8_t*) in_data,
-        .itemsize = in_itemsize,
-        .ndims = in_ndims,
-        .shape = in_shape,
-        .strides = in_strides
-    };
-    ndarray.set_strides_by_shape();
-
-    // Destination ndarray
-    // As documented, ndims and shape & strides must be allocated and determined by the caller.
-    const int32_t dst_ndims = 2;
-    int32_t dst_shape[dst_ndims] = {999, 999}; // Empty values
-    int32_t dst_strides[dst_ndims] = {999, 999}; // Empty values
-    NDArray<int32_t> dst_ndarray = {
-        .data = nullptr,
-        .ndims = dst_ndims,
-        .shape = dst_shape,
-        .strides = dst_strides
-    };
-
-    // Create the slice in `ndarray[-2::, 1::2]`
-    UserSlice<int32_t> user_slice_1 = {
-        .start_defined = 1,
-        .start = -2,
-        .stop_defined = 0,
-        .step_defined = 0
-    };
-
-    UserSlice<int32_t> user_slice_2 = {
-        .start_defined = 1,
-        .start = 1,
-        .stop_defined = 0,
-        .step_defined = 1,
-        .step = 2
-    };
-
-    const int32_t num_ndslices = 2;
-    NDSlice ndslices[num_ndslices] = {
-        { .type = INPUT_SLICE_TYPE_SLICE, .slice = (uint8_t*) &user_slice_1 },
-        { .type = INPUT_SLICE_TYPE_SLICE, .slice = (uint8_t*) &user_slice_2 }
-    };
-
-    ndarray.slice(num_ndslices, ndslices, &dst_ndarray);
-
-    int32_t expected_shape[dst_ndims] = { 2, 2 };
-    int32_t expected_strides[dst_ndims] = { 32, 16 };
-    assert_arrays_match("shape", "%d", dst_ndims, expected_shape, dst_ndarray.shape);
-    assert_arrays_match("strides", "%d", dst_ndims, expected_strides, dst_ndarray.strides);
-
-    assert_values_match("dst_ndarray[0, 0]", "%f", 5.0, *((double *) dst_ndarray.get_pelement((int32_t[dst_ndims]) { 0, 0 })));
-    assert_values_match("dst_ndarray[0, 1]", "%f", 7.0, *((double *) dst_ndarray.get_pelement((int32_t[dst_ndims]) { 0, 1 })));
-    assert_values_match("dst_ndarray[1, 0]", "%f", 9.0, *((double *) dst_ndarray.get_pelement((int32_t[dst_ndims]) { 1, 0 })));
-    assert_values_match("dst_ndarray[1, 1]", "%f", 11.0, *((double *) dst_ndarray.get_pelement((int32_t[dst_ndims]) { 1, 1 })));
-}
-
-void test_ndslice_2() {
-    /*
-        ```python
-        ndarray = np.arange(12, dtype=np.float64).reshape((3, 4))
-        # array([[ 0.,  1.,  2.,  3.],
-        #        [ 4.,  5.,  6.,  7.],
-        #        [ 8.,  9., 10., 11.]])
-
-        dst_ndarray = ndarray[2, ::-2]
-        # array([11.,  9.])
-
-        assert dst_ndarray.shape == (2,)
-        assert dst_ndarray.strides == (-16,)
-        assert dst_ndarray[0] == 11.0
-        assert dst_ndarray[1] == 9.0
-
-        dst_ndarray[1, 0] == 99 # If you write to `dst_ndarray`
-        assert ndarray[1, 3] == 99 # `ndarray` also updates!!
-        ```
-    */
-    BEGIN_TEST();
-
-    double in_data[12] = { 0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0 };
-    int32_t in_itemsize = sizeof(double);
-    const int32_t in_ndims = 2;
-    int32_t in_shape[in_ndims] = { 3, 4 };
-    int32_t in_strides[in_ndims] = {};
-    NDArray<int32_t> ndarray = {
-        .data = (uint8_t*) in_data,
-        .itemsize = in_itemsize,
-        .ndims = in_ndims,
-        .shape = in_shape,
-        .strides = in_strides
-    };
-    ndarray.set_strides_by_shape();
-
-    // Destination ndarray
-    // As documented, ndims and shape & strides must be allocated and determined by the caller.
-    const int32_t dst_ndims = 1;
-    int32_t dst_shape[dst_ndims] = {999}; // Empty values
-    int32_t dst_strides[dst_ndims] = {999}; // Empty values
-    NDArray<int32_t> dst_ndarray = {
-        .data = nullptr,
-        .ndims = dst_ndims,
-        .shape = dst_shape,
-        .strides = dst_strides
-    };
-
-    // Create the slice in `ndarray[2, ::-2]`
-    int32_t user_slice_1 = 2;
-    UserSlice<int32_t> user_slice_2 = {
-        .start_defined = 0,
-        .stop_defined = 0,
-        .step_defined = 1,
-        .step = -2
-    };
-
-    const int32_t num_ndslices = 2;
-    NDSlice ndslices[num_ndslices] = {
-        { .type = INPUT_SLICE_TYPE_INDEX, .slice = (uint8_t*) &user_slice_1 },
-        { .type = INPUT_SLICE_TYPE_SLICE, .slice = (uint8_t*) &user_slice_2 }
-    };
-
-    ndarray.slice(num_ndslices, ndslices, &dst_ndarray);
-
-    int32_t expected_shape[dst_ndims] = { 2 };
-    int32_t expected_strides[dst_ndims] = { -16 };
-    assert_arrays_match("shape", "%d", dst_ndims, expected_shape, dst_ndarray.shape);
-    assert_arrays_match("strides", "%d", dst_ndims, expected_strides, dst_ndarray.strides);
-
-    // [5.0, 3.0]
-    assert_values_match("dst_ndarray[0]", "%f", 11.0, *((double *) dst_ndarray.get_pelement((int32_t[dst_ndims]) { 0 })));
-    assert_values_match("dst_ndarray[1]", "%f", 9.0, *((double *) dst_ndarray.get_pelement((int32_t[dst_ndims]) { 1 })));
-}
-
-void test_can_broadcast_shape() {
-    BEGIN_TEST();
-
-    assert_values_match(
-        "can_broadcast_shape_to([3], [1, 1, 1, 1, 3]) == true",
-        "%d",
-        true,
-        ndarray_util::can_broadcast_shape_to(1, (int32_t[]) { 3 }, 5, (int32_t[]) { 1, 1, 1, 1, 3 })
-    );
-    assert_values_match(
-        "can_broadcast_shape_to([3], [3, 1]) == false",
-        "%d",
-        false,
-        ndarray_util::can_broadcast_shape_to(1, (int32_t[]) { 3 }, 2, (int32_t[]) { 3, 1 }));
-    assert_values_match(
-        "can_broadcast_shape_to([3], [3]) == true",
-        "%d",
-        true,
-        ndarray_util::can_broadcast_shape_to(1, (int32_t[]) { 3 }, 1, (int32_t[]) { 3 }));
-    assert_values_match(
-        "can_broadcast_shape_to([1], [3]) == false",
-        "%d",
-        false,
-        ndarray_util::can_broadcast_shape_to(1, (int32_t[]) { 1 }, 1, (int32_t[]) { 3 }));
-    assert_values_match(
-        "can_broadcast_shape_to([1], [1]) == true",
-        "%d",
-        true,
-        ndarray_util::can_broadcast_shape_to(1, (int32_t[]) { 1 }, 1, (int32_t[]) { 1 }));
-    assert_values_match(
-        "can_broadcast_shape_to([256, 256, 3], [256, 1, 3]) == true",
-        "%d",
-        true,
-        ndarray_util::can_broadcast_shape_to(3, (int32_t[]) { 256, 256, 3 }, 3, (int32_t[]) { 256, 1, 3 })
-    );
-    assert_values_match(
-        "can_broadcast_shape_to([256, 256, 3], [3]) == true",
-        "%d",
-        true,
-        ndarray_util::can_broadcast_shape_to(3, (int32_t[]) { 256, 256, 3 }, 1, (int32_t[]) { 3 })
-    );
-    assert_values_match(
-        "can_broadcast_shape_to([256, 256, 3], [2]) == false",
-        "%d",
-        false,
-        ndarray_util::can_broadcast_shape_to(3, (int32_t[]) { 256, 256, 3 }, 1, (int32_t[]) { 2 })
-    );
-    assert_values_match(
-        "can_broadcast_shape_to([256, 256, 3], [1]) == true",
-        "%d",
-        true,
-        ndarray_util::can_broadcast_shape_to(3, (int32_t[]) { 256, 256, 3 }, 1, (int32_t[]) { 1 })
-    );
-
-    // In cases when the shapes contain zero(es)
-    assert_values_match(
-        "can_broadcast_shape_to([0], [1]) == true",
-        "%d",
-        true,
-        ndarray_util::can_broadcast_shape_to(1, (int32_t[]) { 0 }, 1, (int32_t[]) { 1 })
-    );
-    assert_values_match(
-        "can_broadcast_shape_to([0], [2]) == false",
-        "%d",
-        false,
-        ndarray_util::can_broadcast_shape_to(1, (int32_t[]) { 0 }, 1, (int32_t[]) { 2 })
-    );
-    assert_values_match(
-        "can_broadcast_shape_to([0, 4, 0, 0], [1]) == true",
-        "%d",
-        true,
-        ndarray_util::can_broadcast_shape_to(4, (int32_t[]) { 0, 4, 0, 0 }, 1, (int32_t[]) { 1 })
-    );
-    assert_values_match(
-        "can_broadcast_shape_to([0, 4, 0, 0], [1, 1, 1, 1]) == true",
-        "%d",
-        true,
-        ndarray_util::can_broadcast_shape_to(4, (int32_t[]) { 0, 4, 0, 0 }, 4, (int32_t[]) { 1, 1, 1, 1 })
-    );
-    assert_values_match(
-        "can_broadcast_shape_to([0, 4, 0, 0], [1, 4, 1, 1]) == true",
-        "%d",
-        true,
-        ndarray_util::can_broadcast_shape_to(4, (int32_t[]) { 0, 4, 0, 0 }, 4, (int32_t[]) { 1, 4, 1, 1 })
-    );
-    assert_values_match(
-        "can_broadcast_shape_to([4, 3], [0, 3]) == false",
-        "%d",
-        false,
-        ndarray_util::can_broadcast_shape_to(2, (int32_t[]) { 4, 3 }, 2, (int32_t[]) { 0, 3 })
-    );
-    assert_values_match(
-        "can_broadcast_shape_to([4, 3], [0, 0]) == false",
-        "%d",
-        false,
-        ndarray_util::can_broadcast_shape_to(2, (int32_t[]) { 4, 3 }, 2, (int32_t[]) { 0, 0 })
-    );
-}
-
-void test_ndarray_broadcast_1() {
-    /*
-    # array = np.array([[19.9, 29.9, 39.9, 49.9]], dtype=np.float64)
-    # >>> [[19.9 29.9 39.9 49.9]]
-    #
-    # array = np.broadcast_to(array, (2, 3, 4))
-    # >>> [[[19.9 29.9 39.9 49.9]
-    # >>>   [19.9 29.9 39.9 49.9]
-    # >>>   [19.9 29.9 39.9 49.9]]
-    # >>>  [[19.9 29.9 39.9 49.9]
-    # >>>   [19.9 29.9 39.9 49.9]
-    # >>>   [19.9 29.9 39.9 49.9]]]
-    #
-    # assery array.strides == (0, 0, 8)
-
-    */
-    BEGIN_TEST();
-
-    double in_data[4] = { 19.9, 29.9, 39.9, 49.9 };
-    const int32_t in_ndims = 2;
-    int32_t in_shape[in_ndims] = {1, 4};
-    int32_t in_strides[in_ndims] = {};
-    NDArray<int32_t> ndarray = {
-        .data = (uint8_t*) in_data,
-        .itemsize = sizeof(double),
-        .ndims = in_ndims,
-        .shape = in_shape,
-        .strides = in_strides
-    };
-    ndarray.set_strides_by_shape();
-
-    const int32_t dst_ndims = 3;
-    int32_t dst_shape[dst_ndims] = {2, 3, 4};
-    int32_t dst_strides[dst_ndims] = {};
-    NDArray<int32_t> dst_ndarray = {
-        .ndims = dst_ndims,
-        .shape = dst_shape,
-        .strides = dst_strides
-    };
-
-    ndarray.broadcast_to(&dst_ndarray);
-
-    assert_arrays_match("dst_ndarray->strides", "%d", dst_ndims, (int32_t[]) { 0, 0, 8 }, dst_ndarray.strides);
-
-    assert_values_match("dst_ndarray[0, 0, 0]", "%f", 19.9, *((double*) dst_ndarray.get_pelement((int32_t[]) {0, 0, 0})));
-    assert_values_match("dst_ndarray[0, 0, 1]", "%f", 29.9, *((double*) dst_ndarray.get_pelement((int32_t[]) {0, 0, 1})));
-    assert_values_match("dst_ndarray[0, 0, 2]", "%f", 39.9, *((double*) dst_ndarray.get_pelement((int32_t[]) {0, 0, 2})));
-    assert_values_match("dst_ndarray[0, 0, 3]", "%f", 49.9, *((double*) dst_ndarray.get_pelement((int32_t[]) {0, 0, 3})));
-    assert_values_match("dst_ndarray[0, 1, 0]", "%f", 19.9, *((double*) dst_ndarray.get_pelement((int32_t[]) {0, 1, 0})));
-    assert_values_match("dst_ndarray[0, 1, 1]", "%f", 29.9, *((double*) dst_ndarray.get_pelement((int32_t[]) {0, 1, 1})));
-    assert_values_match("dst_ndarray[0, 1, 2]", "%f", 39.9, *((double*) dst_ndarray.get_pelement((int32_t[]) {0, 1, 2})));
-    assert_values_match("dst_ndarray[0, 1, 3]", "%f", 49.9, *((double*) dst_ndarray.get_pelement((int32_t[]) {0, 1, 3})));
-    assert_values_match("dst_ndarray[1, 2, 3]", "%f", 49.9, *((double*) dst_ndarray.get_pelement((int32_t[]) {1, 2, 3})));
-}
-
-void test_assign_with() {
-    /*
-        ```
-        xs = np.array([[1.0, 2.0, 3.0], [4.0, 5.0, 6.0], [7.0, 8.0, 9.0]], dtype=np.float64)
-        ys = xs.shape
-        ```
-    */
-}
+#include <test/test_core.hpp>
+#include <test/test_ndarray_basic.hpp>
+#include <test/test_ndarray_broadcast.hpp>
+#include <test/test_ndarray_indexing.hpp>
+#include <test/test_slice.hpp>

 int main() {
-    test_calc_size_from_shape_normal();
-    test_calc_size_from_shape_has_zero();
-    test_set_strides_by_shape();
-    test_ndarray_indices_iter_normal();
-    test_ndarray_fill_generic();
-    test_ndarray_set_to_eye();
-    test_slice_1();
-    test_slice_2();
-    test_slice_3();
-    test_slice_4();
-    test_ndslice_1();
-    test_ndslice_2();
-    test_can_broadcast_shape();
-    test_ndarray_broadcast_1();
-    test_assign_with();
+    test::core::run();
+    test::slice::run();
+    test::ndarray_basic::run();
+    test::ndarray_indexing::run();
+    test::ndarray_broadcast::run();
    return 0;
 }
--- a/nac3core/irrt/irrt_typedefs.hpp
+++ b/nac3core/irrt/irrt_typedefs.hpp
@ -1,14 +0,0 @@
-#pragma once
-
-// This is made toggleable since `irrt_test.cpp` itself would include
-// headers that define the `int_t` family.
-#ifndef IRRT_DONT_TYPEDEF_INTS
-typedef _BitInt(8) int8_t;
-typedef unsigned _BitInt(8) uint8_t;
-typedef _BitInt(32) int32_t;
-typedef unsigned _BitInt(32) uint32_t;
-typedef _BitInt(64) int64_t;
-typedef unsigned _BitInt(64) uint64_t;
-#endif
-
-typedef int32_t SliceIndex;
--- a/nac3core/irrt/irrt_utils.hpp
+++ b/nac3core/irrt/irrt_utils.hpp
@ -1,37 +0,0 @@
-#pragma once
-
-#include "irrt_typedefs.hpp"
-
-namespace {
-    template <typename T>
-    T max(T a, T b) {
-        return a > b ? a : b;
-    }
-
-    template <typename T>
-    T min(T a, T b) {
-        return a > b ? b : a;
-    }
-
-    template <typename T>
-    bool arrays_match(int len, T *as, T *bs) {
-        for (int i = 0; i < len; i++) {
-            if (as[i] != bs[i]) return false;
-        }
-        return true;
-    }
-
-    void irrt_panic() {
-        // Crash the program for now.
-        // TODO: Don't crash the program
-        //       ... or at least produce a good message when doing testing IRRT
-            
-        uint8_t* death = nullptr;
-        *death = 0; // TODO: address 0 on hardware might be writable?
-    }
-
-    // TODO: Make this a macro and allow it to be toggled on/off (e.g., debug vs release)
-    void irrt_assert(bool condition) {
-        if (!condition) irrt_panic();
-    }
-}
--- a/nac3core/irrt/test/includes.hpp
+++ b/nac3core/irrt/test/includes.hpp
@ -0,0 +1,11 @@
+#pragma once
+
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+#include <irrt_everything.hpp>
+#include <test/util.hpp>
+
+/*
+    Include this header for every test_*.cpp
+*/
--- a/nac3core/irrt/test/test_core.hpp
+++ b/nac3core/irrt/test/test_core.hpp
@ -0,0 +1,16 @@
+#pragma once
+
+#include <test/includes.hpp>
+
+namespace test {
+namespace core {
+void test_int_exp() {
+    BEGIN_TEST();
+
+    assert_values_match(125, __nac3_int_exp_impl<int32_t>(5, 3));
+    assert_values_match(3125, __nac3_int_exp_impl<int32_t>(5, 5));
+}
+
+void run() { test_int_exp(); }
+}  // namespace core
+}  // namespace test
--- a/nac3core/irrt/test/test_ndarray_basic.hpp
+++ b/nac3core/irrt/test/test_ndarray_basic.hpp
@ -0,0 +1,30 @@
+#pragma once
+
+#include <test/includes.hpp>
+
+namespace test {
+namespace ndarray_basic {
+void test_calc_size_from_shape_normal() {
+    // Test shapes with normal values
+    BEGIN_TEST();
+
+    int32_t shape[4] = {2, 3, 5, 7};
+    assert_values_match(
+        210, ndarray::basic::util::calc_size_from_shape<int32_t>(4, shape));
+}
+
+void test_calc_size_from_shape_has_zero() {
+    // Test shapes with 0 in them
+    BEGIN_TEST();
+
+    int32_t shape[4] = {2, 0, 5, 7};
+    assert_values_match(
+        0, ndarray::basic::util::calc_size_from_shape<int32_t>(4, shape));
+}
+
+void run() {
+    test_calc_size_from_shape_normal();
+    test_calc_size_from_shape_has_zero();
+}
+}  // namespace ndarray_basic
+}  // namespace test
--- a/nac3core/irrt/test/test_ndarray_broadcast.hpp
+++ b/nac3core/irrt/test/test_ndarray_broadcast.hpp
@ -0,0 +1,129 @@
+#pragma once
+
+#include <test/includes.hpp>
+
+namespace test {
+namespace ndarray_broadcast {
+void test_can_broadcast_shape() {
+    BEGIN_TEST();
+
+    assert_values_match(true,
+                        ndarray::broadcast::util::can_broadcast_shape_to(
+                            1, (int32_t[]){3}, 5, (int32_t[]){1, 1, 1, 1, 3}));
+    assert_values_match(false, ndarray::broadcast::util::can_broadcast_shape_to(
+                                   1, (int32_t[]){3}, 2, (int32_t[]){3, 1}));
+    assert_values_match(true, ndarray::broadcast::util::can_broadcast_shape_to(
+                                  1, (int32_t[]){3}, 1, (int32_t[]){3}));
+    assert_values_match(false, ndarray::broadcast::util::can_broadcast_shape_to(
+                                   1, (int32_t[]){1}, 1, (int32_t[]){3}));
+    assert_values_match(true, ndarray::broadcast::util::can_broadcast_shape_to(
+                                  1, (int32_t[]){1}, 1, (int32_t[]){1}));
+    assert_values_match(
+        true, ndarray::broadcast::util::can_broadcast_shape_to(
+                  3, (int32_t[]){256, 256, 3}, 3, (int32_t[]){256, 1, 3}));
+    assert_values_match(true,
+                        ndarray::broadcast::util::can_broadcast_shape_to(
+                            3, (int32_t[]){256, 256, 3}, 1, (int32_t[]){3}));
+    assert_values_match(false,
+                        ndarray::broadcast::util::can_broadcast_shape_to(
+                            3, (int32_t[]){256, 256, 3}, 1, (int32_t[]){2}));
+    assert_values_match(true,
+                        ndarray::broadcast::util::can_broadcast_shape_to(
+                            3, (int32_t[]){256, 256, 3}, 1, (int32_t[]){1}));
+
+    // In cases when the shapes contain zero(es)
+    assert_values_match(true, ndarray::broadcast::util::can_broadcast_shape_to(
+                                  1, (int32_t[]){0}, 1, (int32_t[]){1}));
+    assert_values_match(false, ndarray::broadcast::util::can_broadcast_shape_to(
+                                   1, (int32_t[]){0}, 1, (int32_t[]){2}));
+    assert_values_match(true,
+                        ndarray::broadcast::util::can_broadcast_shape_to(
+                            4, (int32_t[]){0, 4, 0, 0}, 1, (int32_t[]){1}));
+    assert_values_match(
+        true, ndarray::broadcast::util::can_broadcast_shape_to(
+                  4, (int32_t[]){0, 4, 0, 0}, 4, (int32_t[]){1, 1, 1, 1}));
+    assert_values_match(
+        true, ndarray::broadcast::util::can_broadcast_shape_to(
+                  4, (int32_t[]){0, 4, 0, 0}, 4, (int32_t[]){1, 4, 1, 1}));
+    assert_values_match(false, ndarray::broadcast::util::can_broadcast_shape_to(
+                                   2, (int32_t[]){4, 3}, 2, (int32_t[]){0, 3}));
+    assert_values_match(false, ndarray::broadcast::util::can_broadcast_shape_to(
+                                   2, (int32_t[]){4, 3}, 2, (int32_t[]){0, 0}));
+}
+
+void test_ndarray_broadcast() {
+    /*
+    # array = np.array([[19.9, 29.9, 39.9, 49.9]], dtype=np.float64)
+    # >>> [[19.9 29.9 39.9 49.9]]
+    #
+    # array = np.broadcast_to(array, (2, 3, 4))
+    # >>> [[[19.9 29.9 39.9 49.9]
+    # >>>   [19.9 29.9 39.9 49.9]
+    # >>>   [19.9 29.9 39.9 49.9]]
+    # >>>  [[19.9 29.9 39.9 49.9]
+    # >>>   [19.9 29.9 39.9 49.9]
+    # >>>   [19.9 29.9 39.9 49.9]]]
+    #
+    # assery array.strides == (0, 0, 8)
+
+    */
+    BEGIN_TEST();
+
+    double in_data[4] = {19.9, 29.9, 39.9, 49.9};
+    const int32_t in_ndims = 2;
+    int32_t in_shape[in_ndims] = {1, 4};
+    int32_t in_strides[in_ndims] = {};
+    NDArray<int32_t> ndarray = {.data = (uint8_t*)in_data,
+                                .itemsize = sizeof(double),
+                                .ndims = in_ndims,
+                                .shape = in_shape,
+                                .strides = in_strides};
+    ndarray::basic::set_strides_by_shape(&ndarray);
+
+    const int32_t dst_ndims = 3;
+    int32_t dst_shape[dst_ndims] = {2, 3, 4};
+    int32_t dst_strides[dst_ndims] = {};
+    NDArray<int32_t> dst_ndarray = {
+        .ndims = dst_ndims, .shape = dst_shape, .strides = dst_strides};
+
+    ErrorContext errctx = create_testing_errctx();
+    ndarray::broadcast::broadcast_to(&errctx, &ndarray, &dst_ndarray);
+    assert_errctx_no_exception(&errctx);
+
+    assert_arrays_match(dst_ndims, ((int32_t[]){0, 0, 8}), dst_ndarray.strides);
+
+    assert_values_match(19.9,
+                        *((double*)ndarray::basic::get_pelement_by_indices(
+                            &dst_ndarray, ((int32_t[]){0, 0, 0}))));
+    assert_values_match(29.9,
+                        *((double*)ndarray::basic::get_pelement_by_indices(
+                            &dst_ndarray, ((int32_t[]){0, 0, 1}))));
+    assert_values_match(39.9,
+                        *((double*)ndarray::basic::get_pelement_by_indices(
+                            &dst_ndarray, ((int32_t[]){0, 0, 2}))));
+    assert_values_match(49.9,
+                        *((double*)ndarray::basic::get_pelement_by_indices(
+                            &dst_ndarray, ((int32_t[]){0, 0, 3}))));
+    assert_values_match(19.9,
+                        *((double*)ndarray::basic::get_pelement_by_indices(
+                            &dst_ndarray, ((int32_t[]){0, 1, 0}))));
+    assert_values_match(29.9,
+                        *((double*)ndarray::basic::get_pelement_by_indices(
+                            &dst_ndarray, ((int32_t[]){0, 1, 1}))));
+    assert_values_match(39.9,
+                        *((double*)ndarray::basic::get_pelement_by_indices(
+                            &dst_ndarray, ((int32_t[]){0, 1, 2}))));
+    assert_values_match(49.9,
+                        *((double*)ndarray::basic::get_pelement_by_indices(
+                            &dst_ndarray, ((int32_t[]){0, 1, 3}))));
+    assert_values_match(49.9,
+                        *((double*)ndarray::basic::get_pelement_by_indices(
+                            &dst_ndarray, ((int32_t[]){1, 2, 3}))));
+}
+
+void run() {
+    test_can_broadcast_shape();
+    test_ndarray_broadcast();
+}
+}  // namespace ndarray_broadcast
+}  // namespace test
--- a/nac3core/irrt/test/test_ndarray_indexing.hpp
+++ b/nac3core/irrt/test/test_ndarray_indexing.hpp
@ -0,0 +1,220 @@
+#pragma once
+
+#include <test/includes.hpp>
+
+namespace test {
+namespace ndarray_indexing {
+void test_normal_1() {
+    /*
+        Reference Python code:
+        ```python
+        ndarray = np.arange(12, dtype=np.float64).reshape((3, 4));
+        # array([[ 0.,  1.,  2.,  3.],
+        #        [ 4.,  5.,  6.,  7.],
+        #        [ 8.,  9., 10., 11.]])
+
+        dst_ndarray = ndarray[-2:, 1::2]
+        # array([[ 5.,  7.],
+        #        [ 9., 11.]])
+
+        assert dst_ndarray.shape == (2, 2)
+        assert dst_ndarray.strides == (32, 16)
+        assert dst_ndarray[0, 0] == 5.0
+        assert dst_ndarray[0, 1] == 7.0
+        assert dst_ndarray[1, 0] == 9.0
+        assert dst_ndarray[1, 1] == 11.0
+        ```
+    */
+    BEGIN_TEST();
+
+    // Prepare src_ndarray
+    double src_data[12] = {0.0, 1.0, 2.0, 3.0, 4.0,  5.0,
+                           6.0, 7.0, 8.0, 9.0, 10.0, 11.0};
+    int32_t src_itemsize = sizeof(double);
+    const int32_t src_ndims = 2;
+    int32_t src_shape[src_ndims] = {3, 4};
+    int32_t src_strides[src_ndims] = {};
+    NDArray<int32_t> src_ndarray = {.data = (uint8_t *)src_data,
+                                    .itemsize = src_itemsize,
+                                    .ndims = src_ndims,
+                                    .shape = src_shape,
+                                    .strides = src_strides};
+    ndarray::basic::set_strides_by_shape(&src_ndarray);
+
+    // Prepare dst_ndarray
+    const int32_t dst_ndims = 2;
+    int32_t dst_shape[dst_ndims] = {999, 999};    // Empty values
+    int32_t dst_strides[dst_ndims] = {999, 999};  // Empty values
+    NDArray<int32_t> dst_ndarray = {.data = nullptr,
+                                    .ndims = dst_ndims,
+                                    .shape = dst_shape,
+                                    .strides = dst_strides};
+
+    // Create the subscripts in `ndarray[-2::, 1::2]`
+    UserSlice subscript_1;
+    subscript_1.set_start(-2);
+
+    UserSlice subscript_2;
+    subscript_2.set_start(1);
+    subscript_2.set_step(2);
+
+    const int32_t num_indexes = 2;
+    NDIndex indexes[num_indexes] = {
+        {.type = ND_INDEX_TYPE_SLICE, .data = (uint8_t *)&subscript_1},
+        {.type = ND_INDEX_TYPE_SLICE, .data = (uint8_t *)&subscript_2}};
+
+    ErrorContext errctx = create_testing_errctx();
+    ndarray::indexing::index(&errctx, num_indexes, indexes, &src_ndarray,
+                             &dst_ndarray);
+    assert_errctx_no_exception(&errctx);
+
+    int32_t expected_shape[dst_ndims] = {2, 2};
+    int32_t expected_strides[dst_ndims] = {32, 16};
+
+    assert_arrays_match(dst_ndims, expected_shape, dst_ndarray.shape);
+    assert_arrays_match(dst_ndims, expected_strides, dst_ndarray.strides);
+
+    // dst_ndarray[0, 0]
+    assert_values_match(5.0,
+                        *((double *)ndarray::basic::get_pelement_by_indices(
+                            &dst_ndarray, (int32_t[dst_ndims]){0, 0})));
+    // dst_ndarray[0, 1]
+    assert_values_match(7.0,
+                        *((double *)ndarray::basic::get_pelement_by_indices(
+                            &dst_ndarray, (int32_t[dst_ndims]){0, 1})));
+    // dst_ndarray[1, 0]
+    assert_values_match(9.0,
+                        *((double *)ndarray::basic::get_pelement_by_indices(
+                            &dst_ndarray, (int32_t[dst_ndims]){1, 0})));
+    // dst_ndarray[1, 1]
+    assert_values_match(11.0,
+                        *((double *)ndarray::basic::get_pelement_by_indices(
+                            &dst_ndarray, (int32_t[dst_ndims]){1, 1})));
+}
+
+void test_normal_2() {
+    /*
+        ```python
+        ndarray = np.arange(12, dtype=np.float64).reshape((3, 4))
+        # array([[ 0.,  1.,  2.,  3.],
+        #        [ 4.,  5.,  6.,  7.],
+        #        [ 8.,  9., 10., 11.]])
+
+        dst_ndarray = ndarray[2, ::-2]
+        # array([11.,  9.])
+
+        assert dst_ndarray.shape == (2,)
+        assert dst_ndarray.strides == (-16,)
+        assert dst_ndarray[0] == 11.0
+        assert dst_ndarray[1] == 9.0
+        ```
+    */
+    BEGIN_TEST();
+
+    // Prepare src_ndarray
+    double src_data[12] = {0.0, 1.0, 2.0, 3.0, 4.0,  5.0,
+                           6.0, 7.0, 8.0, 9.0, 10.0, 11.0};
+    int32_t src_itemsize = sizeof(double);
+    const int32_t src_ndims = 2;
+    int32_t src_shape[src_ndims] = {3, 4};
+    int32_t src_strides[src_ndims] = {};
+    NDArray<int32_t> src_ndarray = {.data = (uint8_t *)src_data,
+                                    .itemsize = src_itemsize,
+                                    .ndims = src_ndims,
+                                    .shape = src_shape,
+                                    .strides = src_strides};
+    ndarray::basic::set_strides_by_shape(&src_ndarray);
+
+    // Prepare dst_ndarray
+    const int32_t dst_ndims = 1;
+    int32_t dst_shape[dst_ndims] = {999};    // Empty values
+    int32_t dst_strides[dst_ndims] = {999};  // Empty values
+    NDArray<int32_t> dst_ndarray = {.data = nullptr,
+                                    .ndims = dst_ndims,
+                                    .shape = dst_shape,
+                                    .strides = dst_strides};
+
+    // Create the subscripts in `ndarray[2, ::-2]`
+    int32_t subscript_1 = 2;
+
+    UserSlice subscript_2;
+    subscript_2.set_step(-2);
+
+    const int32_t num_indexes = 2;
+    NDIndex indexes[num_indexes] = {
+        {.type = ND_INDEX_TYPE_SINGLE_ELEMENT, .data = (uint8_t *)&subscript_1},
+        {.type = ND_INDEX_TYPE_SLICE, .data = (uint8_t *)&subscript_2}};
+
+    ErrorContext errctx = create_testing_errctx();
+    ndarray::indexing::index(&errctx, num_indexes, indexes, &src_ndarray,
+                             &dst_ndarray);
+    assert_errctx_no_exception(&errctx);
+
+    int32_t expected_shape[dst_ndims] = {2};
+    int32_t expected_strides[dst_ndims] = {-16};
+    assert_arrays_match(dst_ndims, expected_shape, dst_ndarray.shape);
+    assert_arrays_match(dst_ndims, expected_strides, dst_ndarray.strides);
+
+    assert_values_match(11.0,
+                        *((double *)ndarray::basic::get_pelement_by_indices(
+                            &dst_ndarray, (int32_t[dst_ndims]){0})));
+    assert_values_match(9.0,
+                        *((double *)ndarray::basic::get_pelement_by_indices(
+                            &dst_ndarray, (int32_t[dst_ndims]){1})));
+}
+
+void test_index_subscript_out_of_bounds() {
+    /*
+        # Consider `my_array`
+
+        print(my_array.shape)
+        # (4, 5, 6)
+
+        my_array[2, 100] # error, index subscript at axis 1 is out of bounds
+    */
+    BEGIN_TEST();
+
+    // Prepare src_ndarray
+    const int32_t src_ndims = 2;
+    int32_t src_shape[src_ndims] = {3, 4};
+    int32_t src_strides[src_ndims] = {};
+    NDArray<int32_t> src_ndarray = {
+        .data = (uint8_t *)nullptr,  // placeholder, we wouldn't access it
+        .itemsize = sizeof(double),  // placeholder
+        .ndims = src_ndims,
+        .shape = src_shape,
+        .strides = src_strides};
+    ndarray::basic::set_strides_by_shape(&src_ndarray);
+
+    // Create the subscripts in `my_array[2, 100]`
+    int32_t subscript_1 = 2;
+    int32_t subscript_2 = 100;
+
+    const int32_t num_indexes = 2;
+    NDIndex indexes[num_indexes] = {
+        {.type = ND_INDEX_TYPE_SINGLE_ELEMENT, .data = (uint8_t *)&subscript_1},
+        {.type = ND_INDEX_TYPE_SINGLE_ELEMENT,
+         .data = (uint8_t *)&subscript_2}};
+
+    // Prepare dst_ndarray
+    const int32_t dst_ndims = 0;
+    int32_t dst_shape[dst_ndims] = {};
+    int32_t dst_strides[dst_ndims] = {};
+    NDArray<int32_t> dst_ndarray = {.data = nullptr,  // placehloder
+                                    .ndims = dst_ndims,
+                                    .shape = dst_shape,
+                                    .strides = dst_strides};
+
+    ErrorContext errctx = create_testing_errctx();
+    ndarray::indexing::index(&errctx, num_indexes, indexes, &src_ndarray,
+                             &dst_ndarray);
+    assert_errctx_has_exception(&errctx, errctx.exceptions->index_error);
+}
+
+void run() {
+    test_normal_1();
+    test_normal_2();
+    test_index_subscript_out_of_bounds();
+}
+}  // namespace ndarray_indexing
+}  // namespace test
--- a/nac3core/irrt/test/test_slice.hpp
+++ b/nac3core/irrt/test/test_slice.hpp
@ -0,0 +1,92 @@
+#pragma once
+
+#include <irrt_everything.hpp>
+#include <test/includes.hpp>
+
+namespace test {
+namespace slice {
+void test_slice_normal() {
+    // Normal situation
+    BEGIN_TEST();
+
+    UserSlice user_slice;
+    user_slice.set_stop(5);
+
+    Slice slice = user_slice.indices(100);
+
+    printf("%d, %d, %d\n", slice.start, slice.stop, slice.step);
+
+    assert_values_match(0, slice.start);
+    assert_values_match(5, slice.stop);
+    assert_values_match(1, slice.step);
+}
+
+void test_slice_start_too_large() {
+    // Start is too large and should be clamped to length
+    BEGIN_TEST();
+
+    UserSlice user_slice;
+    user_slice.set_start(400);
+
+    Slice slice = user_slice.indices(100);
+
+    assert_values_match(100, slice.start);
+    assert_values_match(100, slice.stop);
+    assert_values_match(1, slice.step);
+}
+
+void test_slice_negative_start_stop() {
+    // Negative start/stop should be resolved
+    BEGIN_TEST();
+
+    UserSlice user_slice;
+    user_slice.set_start(-10);
+    user_slice.set_stop(-5);
+
+    Slice slice = user_slice.indices(100);
+
+    assert_values_match(90, slice.start);
+    assert_values_match(95, slice.stop);
+    assert_values_match(1, slice.step);
+}
+
+void test_slice_only_negative_step() {
+    // Things like `[::-5]` should be handled correctly
+    BEGIN_TEST();
+
+    UserSlice user_slice;
+    user_slice.set_step(-5);
+
+    Slice slice = user_slice.indices(100);
+
+    assert_values_match(99, slice.start);
+    assert_values_match(-1, slice.stop);
+    assert_values_match(-5, slice.step);
+}
+
+void test_slice_step_zero() {
+    // Step = 0 is a value error
+    BEGIN_TEST();
+
+    ErrorContext errctx = create_testing_errctx();
+
+    UserSlice user_slice;
+    user_slice.set_start(2);
+    user_slice.set_stop(12);
+    user_slice.set_step(0);
+
+    Slice slice;
+    user_slice.indices_checked(&errctx, 100, &slice);
+
+    assert_errctx_has_exception(&errctx, errctx.exceptions->value_error);
+}
+
+void run() {
+    test_slice_normal();
+    test_slice_start_too_large();
+    test_slice_negative_start_stop();
+    test_slice_only_negative_step();
+    test_slice_step_zero();
+}
+}  // namespace slice
+}  // namespace test
--- a/nac3core/irrt/test/util.hpp
+++ b/nac3core/irrt/test/util.hpp
@ -0,0 +1,188 @@
+#pragma once
+
+#include <cstdio>
+#include <cstdlib>
+
+template <class T>
+void print_value(const T& value);
+
+template <>
+void print_value(const bool& value) {
+    printf("%s", value ? "true" : "false");
+}
+
+template <>
+void print_value(const int8_t& value) {
+    printf("%d", value);
+}
+
+template <>
+void print_value(const int32_t& value) {
+    printf("%d", value);
+}
+
+template <>
+void print_value(const uint8_t& value) {
+    printf("%u", value);
+}
+
+template <>
+void print_value(const uint32_t& value) {
+    printf("%u", value);
+}
+
+template <>
+void print_value(const float& value) {
+    printf("%f", value);
+}
+
+template <>
+void print_value(const double& value) {
+    printf("%f", value);
+}
+
+void __begin_test(const char* function_name, const char* file, int line) {
+    printf("######### Running %s @ %s:%d\n", function_name, file, line);
+}
+
+#define BEGIN_TEST() __begin_test(__FUNCTION__, __FILE__, __LINE__)
+
+void test_fail() {
+    printf("[!] Test failed. Exiting with status code 1.\n");
+    exit(1);
+}
+
+template <typename T>
+void debug_print_array(int len, const T* as) {
+    printf("[");
+    for (int i = 0; i < len; i++) {
+        if (i != 0) printf(", ");
+        print_value(as[i]);
+    }
+    printf("]");
+}
+
+void print_assertion_passed(const char* file, int line) {
+    printf("[*] Assertion passed on %s:%d\n", file, line);
+}
+
+void print_assertion_failed(const char* file, int line) {
+    printf("[!] Assertion failed on %s:%d\n", file, line);
+}
+
+void __assert_true(const char* file, int line, bool cond) {
+    if (cond) {
+        print_assertion_passed(file, line);
+    } else {
+        print_assertion_failed(file, line);
+        test_fail();
+    }
+}
+
+#define assert_true(cond) __assert_true(__FILE__, __LINE__, cond)
+
+template <typename T>
+void __assert_arrays_match(const char* file, int line, int len,
+                           const T* expected, const T* got) {
+    if (arrays_match(len, expected, got)) {
+        print_assertion_passed(file, line);
+    } else {
+        print_assertion_failed(file, line);
+        printf("Expect = ");
+        debug_print_array(len, expected);
+        printf("\n");
+        printf("   Got = ");
+        debug_print_array(len, got);
+        printf("\n");
+        test_fail();
+    }
+}
+
+#define assert_arrays_match(len, expected, got) \
+    __assert_arrays_match(__FILE__, __LINE__, len, expected, got)
+
+template <typename T>
+void __assert_values_match(const char* file, int line, T expected, T got) {
+    if (expected == got) {
+        print_assertion_passed(file, line);
+    } else {
+        print_assertion_failed(file, line);
+        printf("Expect = ");
+        print_value(expected);
+        printf("\n");
+        printf("   Got = ");
+        print_value(got);
+        printf("\n");
+        test_fail();
+    }
+}
+
+#define assert_values_match(expected, got) \
+    __assert_values_match(__FILE__, __LINE__, expected, got)
+
+// A fake set of ExceptionIds for testing only
+const ErrorContextExceptions TEST_ERROR_CONTEXT_EXCEPTIONS = {
+    .index_error = 0,
+    .value_error = 1,
+    .assertion_error = 2,
+    .runtime_error = 3,
+    .type_error = 4,
+};
+
+ErrorContext create_testing_errctx() {
+    // Everything is global so it is fine to directly return a struct
+    // ErrorContext
+    ErrorContext errctx;
+    errctx.initialize(&TEST_ERROR_CONTEXT_EXCEPTIONS);
+    return errctx;
+}
+
+void print_errctx_content(ErrorContext* errctx) {
+    if (errctx->has_exception()) {
+        printf(
+            "(Exception ID %d): %s ... where param1 = %ld, param2 = %ld, "
+            "param3 = "
+            "%ld\n",
+            errctx->exception_id, errctx->msg, errctx->param1, errctx->param2,
+            errctx->param3);
+    } else {
+        printf("<no exception>\n");
+    }
+}
+
+void __assert_errctx_no_exception(const char* file, int line,
+                                  ErrorContext* errctx) {
+    if (errctx->has_exception()) {
+        print_assertion_failed(file, line);
+        printf("Expecting no exception but caught the following:\n\n");
+        print_errctx_content(errctx);
+        test_fail();
+    }
+}
+
+#define assert_errctx_no_exception(errctx) \
+    __assert_errctx_no_exception(__FILE__, __LINE__, errctx)
+
+void __assert_errctx_has_exception(const char* file, int line,
+                                   ErrorContext* errctx,
+                                   ExceptionId expected_exception_id) {
+    if (errctx->has_exception()) {
+        if (errctx->exception_id != expected_exception_id) {
+            print_assertion_failed(file, line);
+            printf(
+                "Expecting exception id %d but got exception id %d. Error "
+                "caught:\n\n",
+                expected_exception_id, errctx->exception_id);
+            print_errctx_content(errctx);
+            test_fail();
+        }
+    } else {
+        print_assertion_failed(file, line);
+        printf("Expecting an exception, but there is none.");
+        test_fail();
+    }
+}
+
+#define assert_errctx_has_exception(errctx, expected_exception_id) \
+    __assert_errctx_has_exception(__FILE__, __LINE__, errctx,      \
+                                  expected_exception_id)
--- a/nac3core/src/codegen/builtin_fns.rs
+++ b/nac3core/src/codegen/builtin_fns.rs
--- a/nac3core/src/codegen/classes.rs
+++ b/nac3core/src/codegen/classes.rs
@ -1,6 +1,8 @@
 use crate::codegen::{
-    llvm_intrinsics::call_int_umin, stmt::gen_for_callback_incrementing, CodeGenContext,
-    CodeGenerator,
+    irrt::{call_ndarray_calc_size, call_ndarray_flatten_index},
+    llvm_intrinsics::call_int_umin,
+    stmt::gen_for_callback_incrementing,
+    CodeGenContext, CodeGenerator,
 };
 use inkwell::context::Context;
 use inkwell::types::{ArrayType, BasicType, StructType};
@ -10,7 +12,6 @@ use inkwell::{
    values::{BasicValueEnum, IntValue, PointerValue},
    AddressSpace, IntPredicate,
 };
-use itertools::Itertools;

 /// A LLVM type that is used to represent a non-primitive type in NAC3.
 pub trait ProxyType<'ctx>: Into<Self::Base> {
@ -1600,8 +1601,7 @@ impl<'ctx> ArrayLikeValue<'ctx> for NDArrayDataProxy<'ctx, '_> {
        ctx: &CodeGenContext<'ctx, '_>,
        generator: &G,
    ) -> IntValue<'ctx> {
-        todo!()
-        // call_ndarray_calc_size(generator, ctx, &self.as_slice_value(ctx, generator), (None, None))
+        call_ndarray_calc_size(generator, ctx, &self.as_slice_value(ctx, generator), (None, None))
    }
 }

@ -1675,19 +1675,17 @@ impl<'ctx, Index: UntypedArrayLikeAccessor<'ctx>> ArrayLikeIndexer<'ctx, Index>
            indices_elem_ty.get_bit_width()
        );

-        todo!()
+        let index = call_ndarray_flatten_index(generator, ctx, *self.0, indices);

-        // let index = call_ndarray_flatten_index(generator, ctx, *self.0, indices);
-
-        // unsafe {
-        //     ctx.builder
-        //         .build_in_bounds_gep(
-        //             self.base_ptr(ctx, generator),
-        //             &[index],
-        //             name.unwrap_or_default(),
-        //         )
-        //         .unwrap()
-        // }
+        unsafe {
+            ctx.builder
+                .build_in_bounds_gep(
+                    self.base_ptr(ctx, generator),
+                    &[index],
+                    name.unwrap_or_default(),
+                )
+                .unwrap()
+        }
    }

    fn ptr_offset<G: CodeGenerator + ?Sized>(
@ -1719,6 +1717,7 @@ impl<'ctx, Index: UntypedArrayLikeAccessor<'ctx>> ArrayLikeIndexer<'ctx, Index>
        gen_for_callback_incrementing(
            generator,
            ctx,
+            None,
            llvm_usize.const_zero(),
            (len, false),
            |generator, ctx, _, i| {
@ -1763,307 +1762,3 @@ impl<'ctx, Index: UntypedArrayLikeAccessor<'ctx>> UntypedArrayLikeMutator<'ctx,
    for NDArrayDataProxy<'ctx, '_>
 {
 }
-
-#[derive(Debug, Clone, Copy)]
-pub struct StructField<'ctx> {
-    /// The GEP index of this struct field.
-    pub gep_index: u32,
-    /// Name of this struct field.
-    ///
-    /// Used for generating names.
-    pub name: &'static str,
-    /// The type of this struct field.
-    pub ty: BasicTypeEnum<'ctx>,
-}
-
-pub struct StructFields<'ctx> {
-    /// Name of the struct.
-    ///
-    /// Used for generating names.
-    pub name: &'static str,
-
-    /// All the [`StructField`]s of this struct.
-    ///
-    /// **NOTE:** The index position of a [`StructField`]
-    /// matches the element's [`StructField::index`].
-    pub fields: Vec<StructField<'ctx>>,
-}
-
-struct StructFieldsBuilder<'ctx> {
-    gep_index_counter: u32,
-    /// Name of the struct to be built.
-    name: &'static str,
-    fields: Vec<StructField<'ctx>>,
-}
-
-impl<'ctx> StructField<'ctx> {
-    pub fn gep(
-        &self,
-        ctx: &CodeGenContext<'ctx, '_>,
-        ptr: PointerValue<'ctx>,
-    ) -> PointerValue<'ctx> {
-        ctx.builder.build_struct_gep(ptr, self.gep_index, self.name).unwrap()
-    }
-
-    pub fn load(
-        &self,
-        ctx: &CodeGenContext<'ctx, '_>,
-        ptr: PointerValue<'ctx>,
-    ) -> BasicValueEnum<'ctx> {
-        ctx.builder.build_load(self.gep(ctx, ptr), self.name).unwrap()
-    }
-
-    pub fn store<V>(&self, ctx: &CodeGenContext<'ctx, '_>, ptr: PointerValue<'ctx>, value: V)
-    where
-        V: BasicValue<'ctx>,
-    {
-        ctx.builder.build_store(ptr, value).unwrap();
-    }
-}
-
-type IsInstanceError = String;
-type IsInstanceResult = Result<(), IsInstanceError>;
-
-pub fn check_basic_types_match<'ctx, A, B>(expected: A, got: B) -> IsInstanceResult
-where
-    A: BasicType<'ctx>,
-    B: BasicType<'ctx>,
-{
-    let expected = expected.as_basic_type_enum();
-    let got = got.as_basic_type_enum();
-
-    // Put those logic into here,
-    // otherwise there is always a fallback reporting on any kind of mismatch
-    match (expected, got) {
-        (BasicTypeEnum::IntType(expected), BasicTypeEnum::IntType(got)) => {
-            if expected.get_bit_width() != got.get_bit_width() {
-                return Err(format!(
-                    "Expected IntType ({expected}-bit(s)), got IntType ({got}-bit(s))"
-                ));
-            }
-        }
-        (expected, got) => {
-            if expected != got {
-                return Err(format!("Expected {expected}, got {got}"));
-            }
-        }
-    }
-    Ok(())
-}
-
-impl<'ctx> StructFields<'ctx> {
-    pub fn num_fields(&self) -> u32 {
-        self.fields.len() as u32
-    }
-
-    pub fn as_struct_type(&self, ctx: &'ctx Context) -> StructType<'ctx> {
-        let llvm_fields = self.fields.iter().map(|field| field.ty).collect_vec();
-        ctx.struct_type(llvm_fields.as_slice(), false)
-    }
-
-    pub fn is_type(&self, scrutinee: StructType<'ctx>) -> IsInstanceResult {
-        // Check scrutinee's number of struct fields
-        if scrutinee.count_fields() != self.num_fields() {
-            return Err(format!(
-                "Expected {expected_count} field(s) in `{struct_name}` type, got {got_count}",
-                struct_name = self.name,
-                expected_count = self.num_fields(),
-                got_count = scrutinee.count_fields(),
-            ));
-        }
-
-        // Check the scrutinee's field types
-        for field in self.fields.iter() {
-            let expected_field_ty = field.ty;
-            let got_field_ty = scrutinee.get_field_type_at_index(field.gep_index).unwrap();
-
-            if let Err(field_err) = check_basic_types_match(expected_field_ty, got_field_ty) {
-                return Err(format!(
-                    "Field GEP index {gep_index} does not match the expected type of ({struct_name}::{field_name}): {field_err}",
-                    gep_index = field.gep_index,
-                    struct_name = self.name,
-                    field_name = field.name,
-                ));
-            }
-        }
-
-        // Done
-        Ok(())
-    }
-}
-
-impl<'ctx> StructFieldsBuilder<'ctx> {
-    fn start(name: &'static str) -> Self {
-        StructFieldsBuilder { gep_index_counter: 0, name, fields: Vec::new() }
-    }
-
-    fn add_field(&mut self, name: &'static str, ty: BasicTypeEnum<'ctx>) -> StructField<'ctx> {
-        let index = self.gep_index_counter;
-        self.gep_index_counter += 1;
-        StructField { gep_index: index, name, ty }
-    }
-
-    fn end(self) -> StructFields<'ctx> {
-        StructFields { name: self.name, fields: self.fields }
-    }
-}
-
-#[derive(Debug, Clone, Copy)]
-pub struct NpArrayType<'ctx> {
-    pub size_type: IntType<'ctx>,
-    pub elem_type: BasicTypeEnum<'ctx>,
-}
-
-pub struct NpArrayStructFields<'ctx> {
-    pub whole_struct: StructFields<'ctx>,
-    pub data: StructField<'ctx>,
-    pub itemsize: StructField<'ctx>,
-    pub ndims: StructField<'ctx>,
-    pub shape: StructField<'ctx>,
-    pub strides: StructField<'ctx>,
-}
-
-impl<'ctx> NpArrayType<'ctx> {
-    pub fn new_opaque_elem(
-        ctx: &CodeGenContext<'ctx, '_>,
-        size_type: IntType<'ctx>,
-    ) -> NpArrayType<'ctx> {
-        NpArrayType { size_type, elem_type: ctx.ctx.i8_type().as_basic_type_enum() }
-    }
-
-    pub fn struct_type(&self, ctx: &CodeGenContext<'ctx, '_>) -> StructType<'ctx> {
-        self.fields().whole_struct.as_struct_type(ctx.ctx)
-    }
-
-    pub fn fields(&self) -> NpArrayStructFields<'ctx> {
-        let mut builder = StructFieldsBuilder::start("NpArray");
-
-        let addrspace = AddressSpace::default();
-
-        let byte_type = self.size_type.get_context().i8_type();
-
-        // Make sure the struct matches PERFECTLY with that defined in `nac3core/irrt`.
-        let data = builder.add_field("data", byte_type.ptr_type(addrspace).into());
-        let itemsize = builder.add_field("itemsize", self.size_type.into());
-        let ndims = builder.add_field("ndims", self.size_type.into());
-        let shape = builder.add_field("shape", self.size_type.ptr_type(addrspace).into());
-        let strides = builder.add_field("strides", self.size_type.ptr_type(addrspace).into());
-
-        NpArrayStructFields { whole_struct: builder.end(), data, itemsize, ndims, shape, strides }
-    }
-
-    /// Allocate an `ndarray` on stack, with the following notes:
-    ///
-    /// - `ndarray.ndims` will be initialized to `in_ndims`.
-    /// - `ndarray.itemsize` will be initialized to the size of `self.elem_type.size_of()`.
-    /// - `ndarray.shape` and `ndarray.strides` will be allocated on the stack with number of elements being `in_ndims`,
-    /// all with empty/uninitialized values.
-    pub fn alloca(
-        &self,
-        ctx: &CodeGenContext<'ctx, '_>,
-        in_ndims: IntValue<'ctx>,
-        name: &str,
-    ) -> NpArrayValue<'ctx> {
-        let fields = self.fields();
-        let ptr =
-            ctx.builder.build_alloca(fields.whole_struct.as_struct_type(ctx.ctx), name).unwrap();
-
-        // Allocate `in_dims` number of `size_type` on the stack for `shape` and `strides`
-        let allocated_shape =
-            ctx.builder.build_array_alloca(fields.shape.ty, in_ndims, "allocated_shape").unwrap();
-        let allocated_strides = ctx
-            .builder
-            .build_array_alloca(fields.strides.ty, in_ndims, "allocated_strides")
-            .unwrap();
-
-        let value = NpArrayValue { ty: *self, ptr };
-        value.store_ndims(ctx, in_ndims);
-        value.store_itemsize(ctx, self.elem_type.size_of().unwrap());
-        value.store_shape(ctx, allocated_shape);
-        value.store_strides(ctx, allocated_strides);
-
-        return value;
-    }
-}
-
-#[derive(Debug, Clone, Copy)]
-pub struct NpArrayValue<'ctx> {
-    pub ty: NpArrayType<'ctx>,
-    pub ptr: PointerValue<'ctx>,
-}
-
-impl<'ctx> NpArrayValue<'ctx> {
-    pub fn load_ndims(&self, ctx: &CodeGenContext<'ctx, '_>) -> IntValue<'ctx> {
-        let field = self.ty.fields().ndims;
-        field.load(ctx, self.ptr).into_int_value()
-    }
-
-    pub fn store_ndims(&self, ctx: &CodeGenContext<'ctx, '_>, value: IntValue<'ctx>) {
-        let field = self.ty.fields().ndims;
-        field.store(ctx, self.ptr, value);
-    }
-
-    pub fn load_itemsize(&self, ctx: &CodeGenContext<'ctx, '_>) -> IntValue<'ctx> {
-        let field = self.ty.fields().itemsize;
-        field.load(ctx, self.ptr).into_int_value()
-    }
-
-    pub fn store_itemsize(&self, ctx: &CodeGenContext<'ctx, '_>, value: IntValue<'ctx>) {
-        let field = self.ty.fields().itemsize;
-        field.store(ctx, self.ptr, value);
-    }
-
-    pub fn load_shape(&self, ctx: &CodeGenContext<'ctx, '_>) -> PointerValue<'ctx> {
-        let field = self.ty.fields().shape;
-        field.load(ctx, self.ptr).into_pointer_value()
-    }
-
-    pub fn store_shape(&self, ctx: &CodeGenContext<'ctx, '_>, value: PointerValue<'ctx>) {
-        let field = self.ty.fields().shape;
-        field.store(ctx, self.ptr, value);
-    }
-
-    pub fn load_strides(&self, ctx: &CodeGenContext<'ctx, '_>) -> PointerValue<'ctx> {
-        let field = self.ty.fields().strides;
-        field.load(ctx, self.ptr).into_pointer_value()
-    }
-
-    pub fn store_strides(&self, ctx: &CodeGenContext<'ctx, '_>, value: PointerValue<'ctx>) {
-        let field = self.ty.fields().strides;
-        field.store(ctx, self.ptr, value);
-    }
-
-    /// TODO: DOCUMENT ME -- NDIMS WOULD NEVER CHANGE!!!!!
-    pub fn shape_slice(
-        &self,
-        ctx: &CodeGenContext<'ctx, '_>,
-    ) -> TypedArrayLikeAdapter<'ctx, IntValue<'ctx>> {
-        let field = self.ty.fields().shape;
-        field.gep(ctx, self.ptr);
-
-        let ndims = self.load_ndims(ctx);
-
-        TypedArrayLikeAdapter {
-            adapted: ArraySliceValue(self.ptr, ndims, Some(field.name)),
-            downcast_fn: Box::new(|_ctx, x| x.into_int_value()),
-            upcast_fn: Box::new(|_ctx, x| x.as_basic_value_enum()),
-        }
-    }
-
-    /// TODO: DOCUMENT ME -- NDIMS WOULD NEVER CHANGE!!!!!
-    pub fn strides_slice(
-        &self,
-        ctx: &CodeGenContext<'ctx, '_>,
-    ) -> TypedArrayLikeAdapter<'ctx, IntValue<'ctx>> {
-        let field = self.ty.fields().strides;
-        field.gep(ctx, self.ptr);
-
-        let ndims = self.load_ndims(ctx);
-
-        TypedArrayLikeAdapter {
-            adapted: ArraySliceValue(self.ptr, ndims, Some(field.name)),
-            downcast_fn: Box::new(|_ctx, x| x.into_int_value()),
-            upcast_fn: Box::new(|_ctx, x| x.as_basic_value_enum()),
-        }
-    }
-}
--- a/nac3core/src/codegen/expr.rs
+++ b/nac3core/src/codegen/expr.rs
--- a/nac3core/src/codegen/generator.rs
+++ b/nac3core/src/codegen/generator.rs
@ -123,11 +123,12 @@ pub trait CodeGenerator {
        ctx: &mut CodeGenContext<'ctx, '_>,
        target: &Expr<Option<Type>>,
        value: ValueEnum<'ctx>,
+        value_ty: Type,
    ) -> Result<(), String>
    where
        Self: Sized,
    {
-        gen_assign(self, ctx, target, value)
+        gen_assign(self, ctx, target, value, value_ty)
    }

    /// Generate code for a while expression.
--- a/nac3core/src/codegen/irrt/error_context.rs
+++ b/nac3core/src/codegen/irrt/error_context.rs
@ -0,0 +1,198 @@
+use super::util::{function::CallFunction, get_sizet_dependent_function_name};
+use crate::codegen::{
+    model::*,
+    structure::{cslice::CSlice, exception::ExceptionId},
+    CodeGenContext, CodeGenerator,
+};
+
+#[allow(clippy::struct_field_names)]
+pub struct ErrorContextExceptionsFields<F: FieldVisitor> {
+    pub index_error: F::Field<IntModel<ExceptionId>>,
+    pub value_error: F::Field<IntModel<ExceptionId>>,
+    pub assertion_error: F::Field<IntModel<ExceptionId>>,
+    pub runtime_error: F::Field<IntModel<ExceptionId>>,
+    pub type_error: F::Field<IntModel<ExceptionId>>,
+}
+
+/// Corresponds to IRRT's `struct ErrorContextExceptions`
+#[derive(Debug, Clone, Copy, Default, PartialEq, Eq)]
+pub struct ErrorContextExceptions;
+
+impl StructKind for ErrorContextExceptions {
+    type Fields<F: FieldVisitor> = ErrorContextExceptionsFields<F>;
+
+    fn visit_fields<F: FieldVisitor>(&self, visitor: &mut F) -> Self::Fields<F> {
+        Self::Fields {
+            index_error: visitor.add("index_error"),
+            value_error: visitor.add("value_error"),
+            assertion_error: visitor.add("assertion_error"),
+            runtime_error: visitor.add("runtime_error"),
+            type_error: visitor.add("type_error"),
+        }
+    }
+}
+
+pub struct ErrorContextFields<F: FieldVisitor> {
+    pub exceptions: F::Field<PtrModel<StructModel<ErrorContextExceptions>>>,
+    pub exception_id: F::Field<IntModel<ExceptionId>>,
+    pub msg: F::Field<PtrModel<IntModel<Byte>>>,
+    pub param1: F::Field<IntModel<Int64>>,
+    pub param2: F::Field<IntModel<Int64>>,
+    pub param3: F::Field<IntModel<Int64>>,
+}
+
+/// Corresponds to IRRT's `struct ErrorContext`
+#[derive(Debug, Clone, Copy, Default, PartialEq, Eq)]
+pub struct ErrorContext;
+
+impl StructKind for ErrorContext {
+    type Fields<F: FieldVisitor> = ErrorContextFields<F>;
+
+    fn visit_fields<F: FieldVisitor>(&self, visitor: &mut F) -> Self::Fields<F> {
+        Self::Fields {
+            exceptions: visitor.add("exceptions"),
+            exception_id: visitor.add("exception_id"),
+            msg: visitor.add("msg"),
+            param1: visitor.add("param1"),
+            param2: visitor.add("param2"),
+            param3: visitor.add("param3"),
+        }
+    }
+}
+
+/// Build an [`ErrorContextExceptions`] loaded with resolved [`ExceptionID`]s according to the [`SymbolResolver`].
+fn build_error_context_exceptions<'ctx>(
+    tyctx: TypeContext<'ctx>,
+    ctx: &CodeGenContext<'ctx, '_>,
+) -> Ptr<'ctx, StructModel<ErrorContextExceptions>> {
+    let exceptions =
+        StructModel(ErrorContextExceptions).alloca(tyctx, ctx, "error_context_exceptions");
+    let i32_model = IntModel(Int32);
+
+    let get_string_id = |string_id| {
+        i32_model.constant(tyctx, ctx.ctx, ctx.resolver.get_string_id(string_id) as u64)
+    };
+
+    exceptions.gep(ctx, |f| f.index_error).store(ctx, get_string_id("0:IndexError"));
+    exceptions.gep(ctx, |f| f.value_error).store(ctx, get_string_id("0:ValueError"));
+    exceptions.gep(ctx, |f| f.assertion_error).store(ctx, get_string_id("0:AssertionError"));
+    exceptions.gep(ctx, |f| f.runtime_error).store(ctx, get_string_id("0:RuntimeError"));
+    exceptions.gep(ctx, |f| f.type_error).store(ctx, get_string_id("0:TypeError"));
+
+    exceptions
+}
+
+pub fn call_nac3_error_context_initialize<'ctx>(
+    tyctx: TypeContext<'ctx>,
+    ctx: &CodeGenContext<'ctx, '_>,
+    perrctx: Ptr<'ctx, StructModel<ErrorContext>>,
+    pexceptions: Ptr<'ctx, StructModel<ErrorContextExceptions>>,
+) {
+    CallFunction::begin(tyctx, ctx, "__nac3_error_context_initialize")
+        .arg("errctx", perrctx)
+        .arg("exceptions", pexceptions)
+        .returning_void();
+}
+
+pub fn call_nac3_error_context_has_exception<'ctx>(
+    tyctx: TypeContext<'ctx>,
+    ctx: &CodeGenContext<'ctx, '_>,
+    perrctx: Ptr<'ctx, StructModel<ErrorContext>>,
+) -> Int<'ctx, Bool> {
+    CallFunction::begin(tyctx, ctx, "__nac3_error_context_has_exception")
+        .arg("errctx", perrctx)
+        .returning("has_exception")
+}
+
+pub fn call_nac3_error_context_get_exception_str<'ctx>(
+    tyctx: TypeContext<'ctx>,
+    ctx: &CodeGenContext<'ctx, '_>,
+    perrctx: Ptr<'ctx, StructModel<ErrorContext>>,
+    dst_str: Ptr<'ctx, StructModel<CSlice>>,
+) {
+    CallFunction::begin(
+        tyctx,
+        ctx,
+        &get_sizet_dependent_function_name(tyctx, "__nac3_error_context_get_exception_str"),
+    )
+    .arg("errctx", perrctx)
+    .arg("dst_str", dst_str)
+    .returning_void();
+}
+
+/// Setup a [`ErrorContext`] that could be passed to IRRT functions taking in a `ErrorContext* errctx`
+/// for error reporting purposes.
+///
+/// Also see: [`check_error_context`]
+pub fn setup_error_context<'ctx>(
+    tyctx: TypeContext<'ctx>,
+    ctx: &CodeGenContext<'ctx, '_>,
+) -> Ptr<'ctx, StructModel<ErrorContext>> {
+    let errctx_model = StructModel(ErrorContext);
+
+    let exceptions = build_error_context_exceptions(tyctx, ctx);
+    let errctx_ptr = errctx_model.alloca(tyctx, ctx, "errctx");
+
+    call_nac3_error_context_initialize(tyctx, ctx, errctx_ptr, exceptions);
+
+    errctx_ptr
+}
+
+/// Check a [`ErrorContext`] to see if it contains error. **If there is an error,
+/// a Pythonic exception will be raised in the firmware**.
+pub fn check_error_context<'ctx, G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    perrctx: Ptr<'ctx, StructModel<ErrorContext>>,
+) {
+    let tyctx = generator.type_context(ctx.ctx);
+    let cslice_model = StructModel(CSlice);
+
+    let current_bb = ctx.builder.get_insert_block().unwrap();
+    let irrt_has_exception_bb = ctx.ctx.insert_basic_block_after(current_bb, "irrt_has_exception");
+    let end_bb = ctx.ctx.insert_basic_block_after(irrt_has_exception_bb, "end");
+
+    // Inserting into `current_bb`
+    let has_exception = call_nac3_error_context_has_exception(tyctx, ctx, perrctx);
+    ctx.builder
+        .build_conditional_branch(has_exception.value, irrt_has_exception_bb, end_bb)
+        .unwrap();
+
+    // Inserting into `irrt_has_exception_bb`
+    ctx.builder.position_at_end(irrt_has_exception_bb);
+
+    // Load all the values for `ctx.make_assert_impl_by_id`
+    let pexception_str = cslice_model.alloca(tyctx, ctx, "exception_str");
+    call_nac3_error_context_get_exception_str(tyctx, ctx, perrctx, pexception_str);
+
+    let exception_id = perrctx.gep(ctx, |f| f.exception_id).load(tyctx, ctx, "exception_id");
+    let msg = pexception_str.load(tyctx, ctx, "msg");
+    let param1 = perrctx.gep(ctx, |f| f.param1).load(tyctx, ctx, "param1");
+    let param2 = perrctx.gep(ctx, |f| f.param2).load(tyctx, ctx, "param2");
+    let param3 = perrctx.gep(ctx, |f| f.param3).load(tyctx, ctx, "param3");
+
+    ctx.raise_exn_impl(
+        generator,
+        exception_id,
+        msg,
+        [Some(param1), Some(param2), Some(param3)],
+        ctx.current_loc,
+    );
+
+    // Position to `end_bb` for continuation
+    ctx.builder.position_at_end(end_bb);
+}
+
+pub fn call_nac3_dummy_raise<G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext,
+) {
+    let tyctx = generator.type_context(ctx.ctx);
+
+    let errctx = setup_error_context(tyctx, ctx);
+    CallFunction::begin(tyctx, ctx, "__nac3_error_dummy_raise")
+        .arg("errctx", errctx)
+        .returning_void();
+
+    check_error_context(generator, ctx, errctx);
+}
--- a/nac3core/src/codegen/irrt/mod.rs
+++ b/nac3core/src/codegen/irrt/mod.rs
@ -1,11 +1,16 @@
-use crate::{typecheck::typedef::Type, util::SizeVariant};
+use crate::typecheck::typedef::Type;

+pub mod error_context;
+pub mod ndarray;
+pub mod slice;
 mod test;
+mod util;

+use super::model::*;
 use super::{
    classes::{
-        ArrayLikeIndexer, ArrayLikeValue, ArraySliceValue, ListValue, NDArrayValue, NpArrayType,
-        NpArrayValue, TypedArrayLikeAdapter, UntypedArrayLikeAccessor,
+        ArrayLikeIndexer, ArrayLikeValue, ArraySliceValue, ListValue, NDArrayValue,
+        TypedArrayLikeAdapter, UntypedArrayLikeAccessor,
    },
    llvm_intrinsics, CodeGenContext, CodeGenerator,
 };
@ -16,8 +21,8 @@ use inkwell::{
    context::Context,
    memory_buffer::MemoryBuffer,
    module::Module,
-    types::{BasicType, BasicTypeEnum, FunctionType, IntType, PointerType},
-    values::{BasicValueEnum, CallSiteValue, FloatValue, FunctionValue, IntValue},
+    types::{BasicTypeEnum, IntType},
+    values::{BasicValueEnum, CallSiteValue, FloatValue, IntValue},
    AddressSpace, IntPredicate,
 };
 use itertools::Either;
@ -416,14 +421,29 @@ pub fn list_slice_assignment<'ctx, G: CodeGenerator + ?Sized>(
        .unwrap();
    let cond_1 = ctx.builder.build_and(dest_step_eq_one, src_slt_dest, "slice_cond_1").unwrap();
    let cond = ctx.builder.build_or(src_eq_dest, cond_1, "slice_cond").unwrap();
-    ctx.make_assert(
-        generator,
-        cond,
-        "0:ValueError",
-        "attempt to assign sequence of size {0} to slice of size {1} with step size {2}",
-        [Some(src_slice_len), Some(dest_slice_len), Some(dest_idx.2)],
-        ctx.current_loc,
-    );
+
+    // TODO: Temporary fix. Rewrite `list_slice_assignment` later
+    // Exception params should have been i64
+    {
+        let type_context = generator.type_context(ctx.ctx);
+        let param_model = IntModel(Int64);
+
+        let src_slice_len =
+            param_model.s_extend_or_bit_cast(type_context, ctx, src_slice_len, "src_slice_len");
+        let dest_slice_len =
+            param_model.s_extend_or_bit_cast(type_context, ctx, dest_slice_len, "dest_slice_len");
+        let dest_idx_2 =
+            param_model.s_extend_or_bit_cast(type_context, ctx, dest_idx.2, "dest_idx_2");
+
+        ctx.make_assert(
+            generator,
+            cond,
+            "0:ValueError",
+            "attempt to assign sequence of size {0} to slice of size {1} with step size {2}",
+            [Some(src_slice_len.value), Some(dest_slice_len.value), Some(dest_idx_2.value)],
+            ctx.current_loc,
+        );
+    }

    let new_len = {
        let args = vec![
@ -800,6 +820,7 @@ pub fn call_ndarray_calc_broadcast<'ctx, G: CodeGenerator + ?Sized>(
    gen_for_callback_incrementing(
        generator,
        ctx,
+        None,
        llvm_usize.const_zero(),
        (min_ndims, false),
        |generator, ctx, _, idx| {
@ -929,63 +950,3 @@ pub fn call_ndarray_calc_broadcast_index<
        Box::new(|_, v| v.into()),
    )
 }
-
-fn get_size_variant<'ctx>(ty: IntType<'ctx>) -> SizeVariant {
-    match ty.get_bit_width() {
-        32 => SizeVariant::Bits32,
-        64 => SizeVariant::Bits64,
-        _ => unreachable!("Unsupported int type bit width {}", ty.get_bit_width()),
-    }
-}
-
-fn get_size_type_dependent_function<'ctx, BuildFuncTypeFn>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    size_type: IntType<'ctx>,
-    base_name: &str,
-    build_func_type: BuildFuncTypeFn,
-) -> FunctionValue<'ctx>
-where
-    BuildFuncTypeFn: Fn() -> FunctionType<'ctx>,
-{
-    let mut fn_name = base_name.to_owned();
-    match get_size_variant(size_type) {
-        SizeVariant::Bits32 => {
-            // The original fn_name is the correct function name
-        }
-        SizeVariant::Bits64 => {
-            // Append "64" at the end, this is the naming convention for 64-bit
-            fn_name.push_str("64");
-        }
-    }
-
-    // Get (or declare then get if does not exist) the corresponding function
-    ctx.module.get_function(&fn_name).unwrap_or_else(|| {
-        let fn_type = build_func_type();
-        ctx.module.add_function(&fn_name, fn_type, None)
-    })
-}
-
-fn get_ndarray_struct_ptr<'ctx>(ctx: &'ctx Context, size_type: IntType<'ctx>) -> PointerType<'ctx> {
-    let i8_type = ctx.i8_type();
-
-    let ndarray_ty = NpArrayType { size_type, elem_type: i8_type.as_basic_type_enum() };
-    let struct_ty = ndarray_ty.fields().whole_struct.as_struct_type(ctx);
-    struct_ty.ptr_type(AddressSpace::default())
-}
-
-pub fn call_nac3_ndarray_size<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    ndarray: NpArrayValue<'ctx>,
-) -> IntValue<'ctx> {
-    let size_type = ndarray.ty.size_type;
-    let function = get_size_type_dependent_function(ctx, size_type, "__nac3_ndarray_size", || {
-        size_type.fn_type(&[get_ndarray_struct_ptr(ctx.ctx, size_type).into()], false)
-    });
-
-    ctx.builder
-        .build_call(function, &[ndarray.ptr.into()], "size")
-        .unwrap()
-        .try_as_basic_value()
-        .unwrap_left()
-        .into_int_value()
-}
--- a/nac3core/src/codegen/irrt/ndarray/basic.rs
+++ b/nac3core/src/codegen/irrt/ndarray/basic.rs
@ -0,0 +1,153 @@
+use crate::codegen::irrt::error_context::{check_error_context, setup_error_context};
+use crate::codegen::irrt::slice::SliceIndex;
+use crate::codegen::irrt::util::function::CallFunction;
+use crate::codegen::irrt::util::get_sizet_dependent_function_name;
+use crate::codegen::model::*;
+use crate::codegen::structure::ndarray::NpArray;
+use crate::codegen::{CodeGenContext, CodeGenerator};
+
+pub fn call_nac3_ndarray_size<'ctx, G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    ndarray_ptr: Ptr<'ctx, StructModel<NpArray>>,
+) -> Int<'ctx, SizeT> {
+    let tyctx = generator.type_context(ctx.ctx);
+
+    CallFunction::begin(
+        tyctx,
+        ctx,
+        &get_sizet_dependent_function_name(tyctx, "__nac3_ndarray_size"),
+    )
+    .arg("ndarray", ndarray_ptr)
+    .returning("size")
+}
+
+pub fn call_nac3_ndarray_nbytes<'ctx, G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    ndarray_ptr: Ptr<'ctx, StructModel<NpArray>>,
+) -> Int<'ctx, SizeT> {
+    let tyctx = generator.type_context(ctx.ctx);
+
+    CallFunction::begin(
+        tyctx,
+        ctx,
+        &get_sizet_dependent_function_name(tyctx, "__nac3_ndarray_nbytes"),
+    )
+    .arg("ndarray", ndarray_ptr)
+    .returning("nbytes")
+}
+
+pub fn call_nac3_ndarray_len<'ctx, G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    ndarray_ptr: Ptr<'ctx, StructModel<NpArray>>,
+) -> Int<'ctx, SliceIndex> {
+    let tyctx = generator.type_context(ctx.ctx);
+    let slice_index_model = IntModel(SliceIndex::default());
+
+    let dst_len = slice_index_model.alloca(tyctx, ctx, "dst_len");
+
+    let errctx = setup_error_context(tyctx, ctx);
+    CallFunction::begin(
+        tyctx,
+        ctx,
+        &get_sizet_dependent_function_name(tyctx, "__nac3_ndarray_len"),
+    )
+    .arg("errctx", errctx)
+    .arg("ndarray", ndarray_ptr)
+    .arg("dst_len", dst_len)
+    .returning_void();
+    check_error_context(generator, ctx, errctx);
+
+    dst_len.load(tyctx, ctx, "len")
+}
+
+pub fn call_nac3_ndarray_util_assert_shape_no_negative<'ctx, G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    ndims: Int<'ctx, SizeT>,
+    shape: Ptr<'ctx, IntModel<SizeT>>,
+) {
+    let tyctx = generator.type_context(ctx.ctx);
+
+    let errctx = setup_error_context(tyctx, ctx);
+    CallFunction::begin(
+        tyctx,
+        ctx,
+        &get_sizet_dependent_function_name(tyctx, "__nac3_ndarray_util_assert_shape_no_negative"),
+    )
+    .arg("errctx", errctx)
+    .arg("ndims", ndims)
+    .arg("shape", shape)
+    .returning_void();
+    check_error_context(generator, ctx, errctx);
+}
+
+pub fn call_nac3_ndarray_set_strides_by_shape<'ctx, G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    ndarray_ptr: Ptr<'ctx, StructModel<NpArray>>,
+) {
+    let tyctx = generator.type_context(ctx.ctx);
+
+    CallFunction::begin(
+        tyctx,
+        ctx,
+        &get_sizet_dependent_function_name(tyctx, "__nac3_ndarray_set_strides_by_shape"),
+    )
+    .arg("ndarray", ndarray_ptr)
+    .returning_void();
+}
+
+pub fn call_nac3_ndarray_is_c_contiguous<'ctx, G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    ndarray_ptr: Ptr<'ctx, StructModel<NpArray>>,
+) -> Int<'ctx, Bool> {
+    let tyctx = generator.type_context(ctx.ctx);
+
+    CallFunction::begin(
+        tyctx,
+        ctx,
+        &get_sizet_dependent_function_name(tyctx, "__nac3_ndarray_is_c_contiguous"),
+    )
+    .arg("ndarray", ndarray_ptr)
+    .returning("is_c_contiguous")
+}
+
+pub fn call_nac3_ndarray_copy_data<'ctx, G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    src_ndarray: Ptr<'ctx, StructModel<NpArray>>,
+    dst_ndarray: Ptr<'ctx, StructModel<NpArray>>,
+) {
+    let tyctx = generator.type_context(ctx.ctx);
+
+    CallFunction::begin(
+        tyctx,
+        ctx,
+        &get_sizet_dependent_function_name(tyctx, "__nac3_ndarray_copy_data"),
+    )
+    .arg("src_ndarray", src_ndarray)
+    .arg("dst_ndarray", dst_ndarray)
+    .returning_void();
+}
+
+pub fn call_nac3_ndarray_get_nth_pelement<'ctx, G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    pndarray: Ptr<'ctx, StructModel<NpArray>>,
+    index: Int<'ctx, SizeT>,
+) -> Ptr<'ctx, IntModel<Byte>> {
+    let tyctx = generator.type_context(ctx.ctx);
+
+    CallFunction::begin(
+        tyctx,
+        ctx,
+        &get_sizet_dependent_function_name(tyctx, "__nac3_ndarray_get_nth_pelement"),
+    )
+    .arg("ndarray", pndarray)
+    .arg("index", index)
+    .returning("pelement")
+}
--- a/nac3core/src/codegen/irrt/ndarray/broadcast.rs
+++ b/nac3core/src/codegen/irrt/ndarray/broadcast.rs
@ -0,0 +1,74 @@
+use crate::codegen::{
+    irrt::{
+        error_context::{check_error_context, setup_error_context},
+        util::{function::CallFunction, get_sizet_dependent_function_name},
+    },
+    model::*,
+    structure::ndarray::NpArray,
+    CodeGenContext, CodeGenerator,
+};
+
+pub fn call_nac3_ndarray_broadcast_to<'ctx, G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    src_ndarray: Ptr<'ctx, StructModel<NpArray>>,
+    dst_ndarray: Ptr<'ctx, StructModel<NpArray>>,
+) {
+    let tyctx = generator.type_context(ctx.ctx);
+
+    let perrctx = setup_error_context(tyctx, ctx);
+    CallFunction::begin(
+        tyctx,
+        ctx,
+        &get_sizet_dependent_function_name(tyctx, "__nac3_ndarray_broadcast_to"),
+    )
+    .arg("errctx", perrctx)
+    .arg("src_ndarray", src_ndarray)
+    .arg("dst_ndarray", dst_ndarray)
+    .returning_void();
+
+    check_error_context(generator, ctx, perrctx);
+}
+
+/// Fields of [`ShapeEntry`]
+pub struct ShapeEntryFields<F: FieldVisitor> {
+    pub ndims: F::Field<IntModel<SizeT>>,
+    pub shape: F::Field<PtrModel<IntModel<SizeT>>>,
+}
+
+#[derive(Debug, Clone, Copy, Default)]
+pub struct ShapeEntry;
+
+impl StructKind for ShapeEntry {
+    type Fields<F: FieldVisitor> = ShapeEntryFields<F>;
+
+    fn visit_fields<F: FieldVisitor>(&self, visitor: &mut F) -> Self::Fields<F> {
+        Self::Fields { ndims: visitor.add("ndims"), shape: visitor.add("shape") }
+    }
+}
+
+pub fn call_nac3_ndarray_broadcast_shapes<'ctx, G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    num_shape_entries: Int<'ctx, SizeT>,
+    shape_entries: Ptr<'ctx, StructModel<ShapeEntry>>,
+    dst_ndims: Int<'ctx, SizeT>,
+    dst_shape: Ptr<'ctx, IntModel<SizeT>>,
+) {
+    let tyctx = generator.type_context(ctx.ctx);
+
+    let perrctx = setup_error_context(tyctx, ctx);
+    CallFunction::begin(
+        tyctx,
+        ctx,
+        &get_sizet_dependent_function_name(tyctx, "__nac3_ndarray_broadcast_shapes"),
+    )
+    .arg("errctx", perrctx)
+    .arg("num_shapes", num_shape_entries)
+    .arg("shapes", shape_entries)
+    .arg("dst_ndims", dst_ndims)
+    .arg("dst_shape", dst_shape)
+    .returning_void();
+
+    check_error_context(generator, ctx, perrctx);
+}
--- a/nac3core/src/codegen/irrt/ndarray/indexing.rs
+++ b/nac3core/src/codegen/irrt/ndarray/indexing.rs
@ -0,0 +1,170 @@
+use crate::codegen::{
+    irrt::{
+        error_context::{check_error_context, setup_error_context},
+        slice::{RustUserSlice, SliceIndex, UserSlice},
+        util::{function::CallFunction, get_sizet_dependent_function_name},
+    },
+    model::*,
+    structure::ndarray::NpArray,
+    CodeGenContext, CodeGenerator,
+};
+
+pub type NDIndexType = Byte;
+
+#[derive(Debug, Clone, Copy)]
+pub struct NDIndexFields<F: FieldVisitor> {
+    pub type_: F::Field<IntModel<NDIndexType>>, // Defined to be uint8_t in IRRT
+    pub data: F::Field<PtrModel<IntModel<Byte>>>,
+}
+
+#[derive(Debug, Clone, Copy, Default, PartialEq, Eq)]
+pub struct NDIndex;
+
+impl StructKind for NDIndex {
+    type Fields<F: FieldVisitor> = NDIndexFields<F>;
+
+    fn visit_fields<F: FieldVisitor>(&self, visitor: &mut F) -> Self::Fields<F> {
+        Self::Fields { type_: visitor.add("type"), data: visitor.add("data") }
+    }
+}
+
+// An enum variant to store the content
+// and type of an NDIndex in high level.
+#[derive(Debug, Clone)]
+pub enum RustNDIndex<'ctx> {
+    SingleElement(Int<'ctx, SliceIndex>),
+    Slice(RustUserSlice<'ctx>),
+}
+
+impl<'ctx> RustNDIndex<'ctx> {
+    fn get_type_id(&self) -> u64 {
+        // Defined in IRRT, must be in sync
+        match self {
+            RustNDIndex::SingleElement(_) => 0,
+            RustNDIndex::Slice(_) => 1,
+        }
+    }
+
+    fn write_to_ndindex(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &CodeGenContext<'ctx, '_>,
+        dst_ndindex_ptr: Ptr<'ctx, StructModel<NDIndex>>,
+    ) {
+        let ndindex_type_model = IntModel(NDIndexType::default());
+        let slice_index_model = IntModel(SliceIndex::default());
+        let user_slice_model = StructModel(UserSlice);
+
+        // Set `dst_ndindex_ptr->type`
+        dst_ndindex_ptr
+            .gep(ctx, |f| f.type_)
+            .store(ctx, ndindex_type_model.constant(tyctx, ctx.ctx, self.get_type_id()));
+
+        // Set `dst_ndindex_ptr->data`
+        let data = match self {
+            RustNDIndex::SingleElement(in_index) => {
+                let index_ptr = slice_index_model.alloca(tyctx, ctx, "index");
+                index_ptr.store(ctx, *in_index);
+                index_ptr.transmute(tyctx, ctx, IntModel(Byte), "")
+            }
+            RustNDIndex::Slice(in_rust_slice) => {
+                let user_slice_ptr = user_slice_model.alloca(tyctx, ctx, "user_slice");
+                in_rust_slice.write_to_user_slice(tyctx, ctx, user_slice_ptr);
+                user_slice_ptr.transmute(tyctx, ctx, IntModel(Byte), "")
+            }
+        };
+        dst_ndindex_ptr.gep(ctx, |f| f.data).store(ctx, data);
+    }
+
+    /// Allocate an array of `NDIndex`es on the stack and return its stack pointer.
+    pub fn alloca_ndindexes(
+        tyctx: TypeContext<'ctx>,
+        ctx: &CodeGenContext<'ctx, '_>,
+        in_ndindexes: &[RustNDIndex<'ctx>],
+    ) -> (Int<'ctx, SizeT>, Ptr<'ctx, StructModel<NDIndex>>) {
+        let sizet_model = IntModel(SizeT);
+        let ndindex_model = StructModel(NDIndex);
+
+        let num_ndindexes = sizet_model.constant(tyctx, ctx.ctx, in_ndindexes.len() as u64);
+        let ndindexes = ndindex_model.array_alloca(tyctx, ctx, num_ndindexes.value, "ndindexes");
+        for (i, in_ndindex) in in_ndindexes.iter().enumerate() {
+            let i = sizet_model.constant(tyctx, ctx.ctx, i as u64);
+            let pndindex = ndindexes.offset(tyctx, ctx, i.value, "");
+            in_ndindex.write_to_ndindex(tyctx, ctx, pndindex);
+        }
+
+        (num_ndindexes, ndindexes)
+    }
+
+    #[must_use]
+    pub fn deduce_ndims_after_indexing(indices: &[RustNDIndex], original_ndims: u64) -> u64 {
+        let mut final_ndims = original_ndims;
+        for index in indices {
+            match index {
+                RustNDIndex::SingleElement(_) => {
+                    final_ndims -= 1;
+                }
+                RustNDIndex::Slice(_) => {}
+            }
+        }
+        final_ndims
+    }
+}
+
+pub fn call_nac3_ndarray_indexing_deduce_ndims_after_indexing<'ctx, G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    ndims: Int<'ctx, SizeT>,
+    num_ndindexes: Int<'ctx, SizeT>,
+    ndindexs: Ptr<'ctx, StructModel<NDIndex>>,
+) -> Int<'ctx, SizeT> {
+    let tyctx = generator.type_context(ctx.ctx);
+    let sizet_model = IntModel(SizeT);
+
+    let pfinal_ndims = sizet_model.alloca(tyctx, ctx, "pfinal_ndims");
+
+    let errctx_ptr = setup_error_context(tyctx, ctx);
+    CallFunction::begin(
+        tyctx,
+        ctx,
+        &get_sizet_dependent_function_name(
+            tyctx,
+            "__nac3_ndarray_indexing_deduce_ndims_after_indexing",
+        ),
+    )
+    .arg("errctx", errctx_ptr)
+    .arg("result", pfinal_ndims)
+    .arg("ndims", ndims)
+    .arg("num_ndindexs", num_ndindexes)
+    .arg("ndindexs", ndindexs)
+    .returning_void();
+    check_error_context(generator, ctx, errctx_ptr);
+
+    pfinal_ndims.load(tyctx, ctx, "final_ndims")
+}
+
+pub fn call_nac3_ndarray_index<'ctx, G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    num_indexes: Int<'ctx, SizeT>,
+    indexes: Ptr<'ctx, StructModel<NDIndex>>,
+    src_ndarray: Ptr<'ctx, StructModel<NpArray>>,
+    dst_ndarray: Ptr<'ctx, StructModel<NpArray>>,
+) {
+    let tyctx = generator.type_context(ctx.ctx);
+
+    let perrctx = setup_error_context(tyctx, ctx);
+    CallFunction::begin(
+        tyctx,
+        ctx,
+        &get_sizet_dependent_function_name(tyctx, "__nac3_ndarray_index"),
+    )
+    .arg("errctx", perrctx)
+    .arg("num_indexes", num_indexes)
+    .arg("indexes", indexes)
+    .arg("src_ndarray", src_ndarray)
+    .arg("dst_ndarray", dst_ndarray)
+    .returning_void();
+
+    check_error_context(generator, ctx, perrctx);
+}
--- a/nac3core/src/codegen/irrt/ndarray/mod.rs
+++ b/nac3core/src/codegen/irrt/ndarray/mod.rs
@ -0,0 +1,4 @@
+pub mod basic;
+pub mod broadcast;
+pub mod indexing;
+pub mod reshape;
--- a/nac3core/src/codegen/irrt/ndarray/reshape.rs
+++ b/nac3core/src/codegen/irrt/ndarray/reshape.rs
@ -0,0 +1,31 @@
+use crate::codegen::{
+    irrt::{
+        error_context::{check_error_context, setup_error_context},
+        util::{function::CallFunction, get_sizet_dependent_function_name},
+    },
+    model::*,
+    CodeGenContext, CodeGenerator,
+};
+
+pub fn call_nac3_ndarray_resolve_and_check_new_shape<'ctx, G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    size: Int<'ctx, SizeT>,
+    new_ndims: Int<'ctx, SizeT>,
+    new_shape: Ptr<'ctx, IntModel<SizeT>>,
+) {
+    let tyctx = generator.type_context(ctx.ctx);
+
+    let perrctx = setup_error_context(tyctx, ctx);
+    CallFunction::begin(
+        tyctx,
+        ctx,
+        &get_sizet_dependent_function_name(tyctx, "__nac3_ndarray_resolve_and_check_new_shape"),
+    )
+    .arg("errctx", perrctx)
+    .arg("size", size)
+    .arg("new_ndims", new_ndims)
+    .arg("new_shape", new_shape)
+    .returning_void();
+    check_error_context(generator, ctx, perrctx);
+}
--- a/nac3core/src/codegen/irrt/slice.rs
+++ b/nac3core/src/codegen/irrt/slice.rs
@ -0,0 +1,81 @@
+use crate::codegen::{model::*, CodeGenContext};
+
+// nac3core's slicing index/length values are always int32_t
+pub type SliceIndex = Int32;
+
+#[derive(Debug, Clone)]
+pub struct UserSliceFields<F: FieldVisitor> {
+    pub start_defined: F::Field<IntModel<Bool>>,
+    pub start: F::Field<IntModel<SliceIndex>>,
+    pub stop_defined: F::Field<IntModel<Bool>>,
+    pub stop: F::Field<IntModel<SliceIndex>>,
+    pub step_defined: F::Field<IntModel<Bool>>,
+    pub step: F::Field<IntModel<SliceIndex>>,
+}
+
+#[derive(Debug, Clone, Copy, Default, PartialEq, Eq)]
+pub struct UserSlice;
+
+impl StructKind for UserSlice {
+    type Fields<F: FieldVisitor> = UserSliceFields<F>;
+
+    fn visit_fields<F: FieldVisitor>(&self, visitor: &mut F) -> Self::Fields<F> {
+        Self::Fields {
+            start_defined: visitor.add("start_defined"),
+            start: visitor.add("start"),
+            stop_defined: visitor.add("stop_defined"),
+            stop: visitor.add("stop"),
+            step_defined: visitor.add("step_defined"),
+            step: visitor.add("step"),
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct RustUserSlice<'ctx> {
+    pub start: Option<Int<'ctx, SliceIndex>>,
+    pub stop: Option<Int<'ctx, SliceIndex>>,
+    pub step: Option<Int<'ctx, SliceIndex>>,
+}
+
+impl<'ctx> RustUserSlice<'ctx> {
+    // Set the values of an LLVM UserSlice
+    // in the format of Python's `slice()`
+    pub fn write_to_user_slice(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &CodeGenContext<'ctx, '_>,
+        dst_slice_ptr: Ptr<'ctx, StructModel<UserSlice>>,
+    ) {
+        let bool_model = IntModel(Bool);
+
+        let false_ = bool_model.constant(tyctx, ctx.ctx, 0);
+        let true_ = bool_model.constant(tyctx, ctx.ctx, 1);
+
+        // TODO: Code duplication. Probably okay...?
+
+        match self.start {
+            Some(start) => {
+                dst_slice_ptr.gep(ctx, |f| f.start_defined).store(ctx, true_);
+                dst_slice_ptr.gep(ctx, |f| f.start).store(ctx, start);
+            }
+            None => dst_slice_ptr.gep(ctx, |f| f.start_defined).store(ctx, false_),
+        }
+
+        match self.stop {
+            Some(stop) => {
+                dst_slice_ptr.gep(ctx, |f| f.stop_defined).store(ctx, true_);
+                dst_slice_ptr.gep(ctx, |f| f.stop).store(ctx, stop);
+            }
+            None => dst_slice_ptr.gep(ctx, |f| f.stop_defined).store(ctx, false_),
+        }
+
+        match self.step {
+            Some(step) => {
+                dst_slice_ptr.gep(ctx, |f| f.step_defined).store(ctx, true_);
+                dst_slice_ptr.gep(ctx, |f| f.step).store(ctx, step);
+            }
+            None => dst_slice_ptr.gep(ctx, |f| f.step_defined).store(ctx, false_),
+        }
+    }
+}
--- a/nac3core/src/codegen/irrt/util.rs
+++ b/nac3core/src/codegen/irrt/util.rs
@ -0,0 +1,103 @@
+use crate::codegen::model::*;
+
+// When [`TypeContext::size_type`] is 32-bits, the function name is "{fn_name}".
+// When [`TypeContext::size_type`] is 64-bits, the function name is "{fn_name}64".
+#[must_use]
+pub fn get_sizet_dependent_function_name(tyctx: TypeContext<'_>, name: &str) -> String {
+    let mut name = name.to_owned();
+    match tyctx.size_type.get_bit_width() {
+        32 => {}
+        64 => name.push_str("64"),
+        bit_width => {
+            panic!("Unsupported int type bit width {bit_width}, must be either 32-bits or 64-bits")
+        }
+    }
+    name
+}
+
+pub mod function {
+    use crate::codegen::{model::*, CodeGenContext};
+    use inkwell::{
+        types::{BasicMetadataTypeEnum, BasicType, FunctionType},
+        values::{AnyValue, BasicMetadataValueEnum, BasicValue, BasicValueEnum, CallSiteValue},
+    };
+    use itertools::Itertools;
+
+    #[derive(Debug, Clone, Copy)]
+    struct Arg<'ctx> {
+        ty: BasicMetadataTypeEnum<'ctx>,
+        val: BasicMetadataValueEnum<'ctx>,
+    }
+
+    /// Helper structure to reduce IRRT Inkwell function call boilerplate
+    /// TODO: Optimize
+    pub struct CallFunction<'ctx, 'a, 'b, 'c> {
+        tyctx: TypeContext<'ctx>,
+        ctx: &'b CodeGenContext<'ctx, 'a>,
+        /// Function name
+        name: &'c str,
+        /// Call arguments
+        args: Vec<Arg<'ctx>>,
+    }
+
+    impl<'ctx, 'a, 'b, 'c> CallFunction<'ctx, 'a, 'b, 'c> {
+        pub fn begin(
+            tyctx: TypeContext<'ctx>,
+            ctx: &'b CodeGenContext<'ctx, 'a>,
+            name: &'c str,
+        ) -> Self {
+            CallFunction { tyctx, ctx, name, args: Vec::new() }
+        }
+
+        /// Push a call argument to the function call.
+        ///
+        /// The `_name` parameter is there for self-documentation purposes.
+        #[allow(clippy::needless_pass_by_value)]
+        pub fn arg<M: Model>(mut self, _name: &str, arg: Instance<'ctx, M>) -> Self {
+            let arg = Arg {
+                ty: arg.model.get_type(self.tyctx, self.ctx.ctx).as_basic_type_enum().into(),
+                val: arg.value.as_basic_value_enum().into(),
+            };
+            self.args.push(arg);
+            self
+        }
+
+        /// Like [`CallFunction::returning_`] but `return_model` is automatically inferred.
+        pub fn returning<M: Model>(self, name: &str) -> Instance<'ctx, M> {
+            self.returning_(name, M::default())
+        }
+
+        /// Call the function and expect the function to return a value of type of `return_model`.
+        pub fn returning_<M: Model>(self, name: &str, return_model: M) -> Instance<'ctx, M> {
+            let ret_ty = return_model.get_type(self.tyctx, self.ctx.ctx);
+
+            let ret = self.get_function(|tys| ret_ty.fn_type(tys, false), name);
+            let ret = BasicValueEnum::try_from(ret.as_any_value_enum()).unwrap(); // Must work
+            let ret = return_model.check_value(self.tyctx, self.ctx.ctx, ret).unwrap(); // Must work
+            ret
+        }
+
+        /// Call the function and expect the function to return a void-type.
+        pub fn returning_void(self) {
+            let ret_ty = self.ctx.ctx.void_type();
+
+            let _ = self.get_function(|tys| ret_ty.fn_type(tys, false), "");
+        }
+
+        fn get_function<F>(&self, make_fn_type: F, return_value_name: &str) -> CallSiteValue<'ctx>
+        where
+            F: FnOnce(&[BasicMetadataTypeEnum<'ctx>]) -> FunctionType<'ctx>,
+        {
+            // Get the LLVM function, declare the function if it doesn't exist - it will be defined by other
+            // components of NAC3.
+            let func = self.ctx.module.get_function(self.name).unwrap_or_else(|| {
+                let tys = self.args.iter().map(|arg| arg.ty).collect_vec();
+                let fn_type = make_fn_type(&tys);
+                self.ctx.module.add_function(self.name, fn_type, None)
+            });
+
+            let vals = self.args.iter().map(|arg| arg.val).collect_vec();
+            self.ctx.builder.build_call(func, &vals, return_value_name).unwrap()
+        }
+    }
+}
--- a/nac3core/src/codegen/mod.rs
+++ b/nac3core/src/codegen/mod.rs
@ -1,7 +1,7 @@
 use crate::{
-    codegen::classes::{ListType, NDArrayType, ProxyType, RangeType},
+    codegen::classes::{ListType, ProxyType, RangeType},
    symbol_resolver::{StaticValue, SymbolResolver},
-    toplevel::{helper::PrimDef, numpy::unpack_ndarray_var_tys, TopLevelContext, TopLevelDef},
+    toplevel::{helper::PrimDef, TopLevelContext, TopLevelDef},
    typecheck::{
        type_inferencer::{CodeLocation, PrimitiveStore},
        typedef::{CallId, FuncArg, Type, TypeEnum, Unifier},
@ -24,6 +24,7 @@ use inkwell::{
    AddressSpace, IntPredicate, OptimizationLevel,
 };
 use itertools::Itertools;
+use model::*;
 use nac3parser::ast::{Location, Stmt, StrRef};
 use parking_lot::{Condvar, Mutex};
 use std::collections::{HashMap, HashSet};
@ -32,6 +33,7 @@ use std::sync::{
    Arc,
 };
 use std::thread;
+use structure::{cslice::CSlice, exception::Exception, ndarray::NpArray};

 pub mod builtin_fns;
 pub mod classes;
@ -41,8 +43,12 @@ pub mod extern_fns;
 mod generator;
 pub mod irrt;
 pub mod llvm_intrinsics;
+pub mod model;
 pub mod numpy;
+pub mod numpy_new;
 pub mod stmt;
+pub mod structure;
+pub mod util;

 #[cfg(test)]
 mod test;
@ -68,6 +74,16 @@ pub struct CodeGenLLVMOptions {
    pub target: CodeGenTargetMachineOptions,
 }

+impl CodeGenLLVMOptions {
+    /// Creates a [`TargetMachine`] using the target options specified by this struct.
+    ///
+    /// See [`Target::create_target_machine`].
+    #[must_use]
+    pub fn create_target_machine(&self) -> Option<TargetMachine> {
+        self.target.create_target_machine(self.opt_level)
+    }
+}
+
 /// Additional options for code generation for the target machine.
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub struct CodeGenTargetMachineOptions {
@ -158,11 +174,11 @@ pub struct CodeGenContext<'ctx, 'a> {
    pub registry: &'a WorkerRegistry,

    /// Cache for constant strings.
-    pub const_strings: HashMap<String, BasicValueEnum<'ctx>>,
+    pub const_strings: HashMap<String, Struct<'ctx, CSlice>>,

    /// [`BasicBlock`] containing all `alloca` statements for the current function.
    pub init_bb: BasicBlock<'ctx>,
-    pub exception_val: Option<PointerValue<'ctx>>,
+    pub exception_val: Option<Ptr<'ctx, StructModel<Exception>>>,

    /// The header and exit basic blocks of a loop in this context. See
    /// <https://llvm.org/docs/LoopTerminology.html> for explanation of these terminology.
@ -338,6 +354,10 @@ impl WorkerRegistry {
        let mut builder = context.create_builder();
        let mut module = context.create_module(generator.get_name());

+        let target_machine = self.llvm_options.create_target_machine().unwrap();
+        module.set_data_layout(&target_machine.get_target_data().get_data_layout());
+        module.set_triple(&target_machine.get_triple());
+
        module.add_basic_value_flag(
            "Debug Info Version",
            inkwell::module::FlagBehavior::Warning,
@ -361,6 +381,10 @@ impl WorkerRegistry {
                    errors.insert(e);
                    // create a new empty module just to continue codegen and collect errors
                    module = context.create_module(&format!("{}_recover", generator.get_name()));
+
+                    let target_machine = self.llvm_options.create_target_machine().unwrap();
+                    module.set_data_layout(&target_machine.get_target_data().get_data_layout());
+                    module.set_triple(&target_machine.get_triple());
                }
            }
            *self.task_count.lock() -= 1;
@ -471,12 +495,9 @@ fn get_llvm_type<'ctx, G: CodeGenerator + ?Sized>(
                        }

                        TObj { obj_id, .. } if *obj_id == PrimDef::NDArray.id() => {
-                            let (dtype, _) = unpack_ndarray_var_tys(unifier, ty);
-                            let element_type = get_llvm_type(
-                                ctx, module, generator, unifier, top_level, type_cache, dtype,
-                            );
-
-                            NDArrayType::new(generator, ctx, element_type).as_base_type().into()
+                            let tyctx = generator.type_context(ctx);
+                            let pndarray_model = PtrModel(StructModel(NpArray));
+                            pndarray_model.get_type(tyctx, ctx).into()
                        }

                        _ => unreachable!(
@ -646,43 +667,20 @@ pub fn gen_func_impl<
        ..primitives
    };

-    let mut type_cache: HashMap<_, _> = [
+    let type_context = generator.type_context(context);
+    let cslice_model = StructModel(CSlice);
+    let pexn_model = PtrModel(StructModel(Exception));
+
+    let mut type_cache: HashMap<_, BasicTypeEnum<'ctx>> = [
        (primitives.int32, context.i32_type().into()),
        (primitives.int64, context.i64_type().into()),
        (primitives.uint32, context.i32_type().into()),
        (primitives.uint64, context.i64_type().into()),
        (primitives.float, context.f64_type().into()),
        (primitives.bool, context.i8_type().into()),
-        (primitives.str, {
-            let name = "str";
-            match module.get_struct_type(name) {
-                None => {
-                    let str_type = context.opaque_struct_type("str");
-                    let fields = [
-                        context.i8_type().ptr_type(AddressSpace::default()).into(),
-                        generator.get_size_type(context).into(),
-                    ];
-                    str_type.set_body(&fields, false);
-                    str_type.into()
-                }
-                Some(t) => t.as_basic_type_enum(),
-            }
-        }),
+        (primitives.str, cslice_model.get_type(type_context, context).into()),
        (primitives.range, RangeType::new(context).as_base_type().into()),
-        (primitives.exception, {
-            let name = "Exception";
-            if let Some(t) = module.get_struct_type(name) {
-                t.ptr_type(AddressSpace::default()).as_basic_type_enum()
-            } else {
-                let exception = context.opaque_struct_type("Exception");
-                let int32 = context.i32_type().into();
-                let int64 = context.i64_type().into();
-                let str_ty = module.get_struct_type("str").unwrap().as_basic_type_enum();
-                let fields = [int32, str_ty, int32, int32, str_ty, str_ty, int64, int64, int64];
-                exception.set_body(&fields, false);
-                exception.ptr_type(AddressSpace::default()).as_basic_type_enum()
-            }
-        }),
+        (primitives.exception, pexn_model.get_type(type_context, context).into()),
    ]
    .iter()
    .copied()
--- a/nac3core/src/codegen/model/core.rs
+++ b/nac3core/src/codegen/model/core.rs
@ -0,0 +1,161 @@
+use std::fmt;
+
+use inkwell::{context::Context, types::*, values::*};
+
+use super::*;
+use crate::codegen::{CodeGenContext, CodeGenerator};
+
+#[derive(Clone, Copy)]
+pub struct TypeContext<'ctx> {
+    pub size_type: IntType<'ctx>,
+}
+
+pub trait HasTypeContext {
+    fn type_context<'ctx>(&self, ctx: &'ctx Context) -> TypeContext<'ctx>;
+}
+
+impl<T: CodeGenerator + ?Sized> HasTypeContext for T {
+    fn type_context<'ctx>(&self, ctx: &'ctx Context) -> TypeContext<'ctx> {
+        TypeContext { size_type: self.get_size_type(ctx) }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct ModelError(pub String);
+
+impl ModelError {
+    pub(super) fn under_context(mut self, context: &str) -> Self {
+        self.0.push_str(" ... in ");
+        self.0.push_str(context);
+        self
+    }
+}
+
+/// A [`Model`] is a singleton object that uniquely identifies a [`BasicType`]
+/// solely from a [`CodeGenerator`] and a [`Context`].
+pub trait Model: CheckType + fmt::Debug + Clone + Copy + Default {
+    type Value<'ctx>: BasicValue<'ctx> + TryFrom<BasicValueEnum<'ctx>>;
+    type Type<'ctx>: BasicType<'ctx>;
+
+    /// Return the [`BasicType`] of this model.
+    fn get_type<'ctx>(&self, tyctx: TypeContext<'ctx>, ctx: &'ctx Context) -> Self::Type<'ctx>;
+
+    /// Check if a [`BasicType`] is the same type of this model.
+    fn check_type<'ctx, T: BasicType<'ctx>>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &'ctx Context,
+        ty: T,
+    ) -> Result<(), ModelError> {
+        let ty = ty.as_basic_type_enum();
+        self.check_type_impl(tyctx, ctx, ty.as_basic_type_enum())
+    }
+
+    /// Create an instance from a value with [`Instance::model`] being this model.
+    ///
+    /// Caller must make sure the type of `value` and the type of this `model` are equivalent.
+    fn believe_value<'ctx>(&self, value: Self::Value<'ctx>) -> Instance<'ctx, Self> {
+        Instance { model: *self, value }
+    }
+
+    /// Check if a [`BasicValue`]'s type is equivalent to the type of this model.
+    /// Wrap it into an [`Instance`] if it is.
+    fn check_value<'ctx, V: BasicValue<'ctx>>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &'ctx Context,
+        value: V,
+    ) -> Result<Instance<'ctx, Self>, ModelError> {
+        let value = value.as_basic_value_enum();
+        self.check_type(tyctx, ctx, value.get_type())
+            .map_err(|err| err.under_context("the value {value:?}"))?;
+
+        let Ok(value) = Self::Value::try_from(value) else {
+            unreachable!("check_type() has bad implementation")
+        };
+        Ok(self.believe_value(value))
+    }
+
+    // Allocate a value on the stack and return its pointer.
+    fn alloca<'ctx>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &CodeGenContext<'ctx, '_>,
+        name: &str,
+    ) -> Ptr<'ctx, Self> {
+        let pmodel = PtrModel(*self);
+        let p = ctx.builder.build_alloca(self.get_type(tyctx, ctx.ctx), name).unwrap();
+        pmodel.believe_value(p)
+    }
+
+    // Allocate an array on the stack and return its pointer.
+    fn array_alloca<'ctx>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &CodeGenContext<'ctx, '_>,
+        len: IntValue<'ctx>,
+        name: &str,
+    ) -> Ptr<'ctx, Self> {
+        let pmodel = PtrModel(*self);
+        let p = ctx.builder.build_array_alloca(self.get_type(tyctx, ctx.ctx), len, name).unwrap();
+        pmodel.believe_value(p)
+    }
+
+    fn var_alloca<'ctx, G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+        name: Option<&str>,
+    ) -> Result<Ptr<'ctx, Self>, String> {
+        let tyctx = generator.type_context(ctx.ctx);
+
+        let pmodel = PtrModel(*self);
+        let p = generator.gen_var_alloc(
+            ctx,
+            self.get_type(tyctx, ctx.ctx).as_basic_type_enum(),
+            name,
+        )?;
+        Ok(pmodel.believe_value(p))
+    }
+
+    fn array_var_alloca<'ctx, G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+        len: IntValue<'ctx>,
+        name: Option<&'ctx str>,
+    ) -> Result<Ptr<'ctx, Self>, String> {
+        let tyctx = generator.type_context(ctx.ctx);
+
+        // TODO: Remove ArraySliceValue
+        let pmodel = PtrModel(*self);
+        let p = generator.gen_array_var_alloc(
+            ctx,
+            self.get_type(tyctx, ctx.ctx).as_basic_type_enum(),
+            len,
+            name,
+        )?;
+        Ok(pmodel.believe_value(PointerValue::from(p)))
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+pub struct Instance<'ctx, M: Model> {
+    /// The model of this instance.
+    pub model: M,
+    /// The value of this instance.
+    ///
+    /// Caller must make sure the type of `value` and the type of this `model` are equivalent,
+    /// down to having the same [`IntType::get_bit_width`] in case of [`IntType`] for example.
+    pub value: M::Value<'ctx>,
+}
+
+// NOTE: Must be Rust object-safe - This must be typeable for a Rust trait object.
+pub trait CheckType {
+    fn check_type_impl<'ctx>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &'ctx Context,
+        ty: BasicTypeEnum<'ctx>,
+    ) -> Result<(), ModelError>;
+}
--- a/nac3core/src/codegen/model/int.rs
+++ b/nac3core/src/codegen/model/int.rs
@ -0,0 +1,228 @@
+use std::fmt;
+
+use inkwell::{
+    context::Context,
+    types::{BasicTypeEnum, IntType},
+    values::IntValue,
+    IntPredicate,
+};
+
+use crate::codegen::{CodeGenContext, CodeGenerator};
+
+use super::*;
+
+pub trait IntKind: fmt::Debug + Clone + Copy + Default {
+    fn get_int_type<'ctx>(&self, tyctx: TypeContext<'ctx>, ctx: &'ctx Context) -> IntType<'ctx>;
+}
+
+#[derive(Debug, Clone, Copy, Default)]
+pub struct Bool;
+#[derive(Debug, Clone, Copy, Default)]
+pub struct Byte;
+#[derive(Debug, Clone, Copy, Default)]
+pub struct Int32;
+#[derive(Debug, Clone, Copy, Default)]
+pub struct Int64;
+#[derive(Debug, Clone, Copy, Default)]
+pub struct SizeT;
+
+impl IntKind for Bool {
+    fn get_int_type<'ctx>(&self, _tyctx: TypeContext<'ctx>, ctx: &'ctx Context) -> IntType<'ctx> {
+        ctx.bool_type()
+    }
+}
+
+impl IntKind for Byte {
+    fn get_int_type<'ctx>(&self, _tyctx: TypeContext<'ctx>, ctx: &'ctx Context) -> IntType<'ctx> {
+        ctx.i8_type()
+    }
+}
+
+impl IntKind for Int32 {
+    fn get_int_type<'ctx>(&self, _tyctx: TypeContext<'ctx>, ctx: &'ctx Context) -> IntType<'ctx> {
+        ctx.i32_type()
+    }
+}
+
+impl IntKind for Int64 {
+    fn get_int_type<'ctx>(&self, _tyctx: TypeContext<'ctx>, ctx: &'ctx Context) -> IntType<'ctx> {
+        ctx.i64_type()
+    }
+}
+
+impl IntKind for SizeT {
+    fn get_int_type<'ctx>(&self, tyctx: TypeContext<'ctx>, _ctx: &'ctx Context) -> IntType<'ctx> {
+        tyctx.size_type
+    }
+}
+
+#[derive(Debug, Clone, Copy, Default)]
+pub struct IntModel<N: IntKind>(pub N);
+pub type Int<'ctx, N> = Instance<'ctx, IntModel<N>>;
+
+impl<N: IntKind> CheckType for IntModel<N> {
+    fn check_type_impl<'ctx>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &'ctx Context,
+        ty: BasicTypeEnum<'ctx>,
+    ) -> Result<(), ModelError> {
+        let Ok(ty) = IntType::try_from(ty) else {
+            return Err(ModelError(format!("Expecting IntType, but got {ty:?}")));
+        };
+
+        let exp_ty = self.0.get_int_type(tyctx, ctx);
+        if ty.get_bit_width() != exp_ty.get_bit_width() {
+            return Err(ModelError(format!(
+                "Expecting IntType to have {} bit(s), but got {} bit(s)",
+                exp_ty.get_bit_width(),
+                ty.get_bit_width()
+            )));
+        }
+
+        Ok(())
+    }
+}
+
+impl<N: IntKind> Model for IntModel<N> {
+    type Value<'ctx> = IntValue<'ctx>;
+    type Type<'ctx> = IntType<'ctx>;
+
+    #[must_use]
+    fn get_type<'ctx>(&self, tyctx: TypeContext<'ctx>, ctx: &'ctx Context) -> Self::Type<'ctx> {
+        self.0.get_int_type(tyctx, ctx)
+    }
+}
+
+impl<N: IntKind> IntModel<N> {
+    pub fn constant<'ctx>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &'ctx Context,
+        value: u64,
+    ) -> Int<'ctx, N> {
+        let value = self.get_type(tyctx, ctx).const_int(value, false);
+        self.believe_value(value)
+    }
+
+    pub fn const_0<'ctx>(&self, tyctx: TypeContext<'ctx>, ctx: &'ctx Context) -> Int<'ctx, N> {
+        self.constant(tyctx, ctx, 0)
+    }
+
+    pub fn const_1<'ctx>(&self, tyctx: TypeContext<'ctx>, ctx: &'ctx Context) -> Int<'ctx, N> {
+        self.constant(tyctx, ctx, 1)
+    }
+
+    pub fn s_extend_or_bit_cast<'ctx>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &CodeGenContext<'ctx, '_>,
+        value: IntValue<'ctx>,
+        name: &str,
+    ) -> Int<'ctx, N> {
+        let value = ctx
+            .builder
+            .build_int_s_extend_or_bit_cast(value, self.get_type(tyctx, ctx.ctx), name)
+            .unwrap();
+        self.believe_value(value)
+    }
+
+    pub fn truncate<'ctx>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &CodeGenContext<'ctx, '_>,
+        value: IntValue<'ctx>,
+        name: &str,
+    ) -> Int<'ctx, N> {
+        let value =
+            ctx.builder.build_int_truncate(value, self.get_type(tyctx, ctx.ctx), name).unwrap();
+        self.believe_value(value)
+    }
+}
+
+impl IntModel<Bool> {
+    #[must_use]
+    pub fn const_false<'ctx>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &'ctx Context,
+    ) -> Int<'ctx, Bool> {
+        self.constant(tyctx, ctx, 0)
+    }
+
+    #[must_use]
+    pub fn const_true<'ctx>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &'ctx Context,
+    ) -> Int<'ctx, Bool> {
+        self.constant(tyctx, ctx, 1)
+    }
+}
+
+impl<'ctx, N: IntKind> Int<'ctx, N> {
+    pub fn s_extend_or_bit_cast<NewN: IntKind, G: CodeGenerator + ?Sized>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &CodeGenContext<'ctx, '_>,
+        to_int_kind: NewN,
+        name: &str,
+    ) -> Int<'ctx, NewN> {
+        IntModel(to_int_kind).s_extend_or_bit_cast(tyctx, ctx, self.value, name)
+    }
+
+    pub fn truncate<NewN: IntKind, G: CodeGenerator + ?Sized>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &CodeGenContext<'ctx, '_>,
+        to_int_kind: NewN,
+        name: &str,
+    ) -> Int<'ctx, NewN> {
+        IntModel(to_int_kind).truncate(tyctx, ctx, self.value, name)
+    }
+
+    #[must_use]
+    pub fn add<G: CodeGenerator + ?Sized>(
+        &self,
+        ctx: &CodeGenContext<'ctx, '_>,
+        other: Int<'ctx, N>,
+        name: &str,
+    ) -> Int<'ctx, N> {
+        let value = ctx.builder.build_int_add(self.value, other.value, name).unwrap();
+        self.model.believe_value(value)
+    }
+
+    #[must_use]
+    pub fn sub<G: CodeGenerator + ?Sized>(
+        &self,
+        ctx: &CodeGenContext<'ctx, '_>,
+        other: Int<'ctx, N>,
+        name: &str,
+    ) -> Int<'ctx, N> {
+        let value = ctx.builder.build_int_sub(self.value, other.value, name).unwrap();
+        self.model.believe_value(value)
+    }
+
+    #[must_use]
+    pub fn mul<G: CodeGenerator + ?Sized>(
+        &self,
+        ctx: &CodeGenContext<'ctx, '_>,
+        other: Int<'ctx, N>,
+        name: &str,
+    ) -> Int<'ctx, N> {
+        let value = ctx.builder.build_int_mul(self.value, other.value, name).unwrap();
+        self.model.believe_value(value)
+    }
+
+    pub fn compare<G: CodeGenerator + ?Sized>(
+        &self,
+        ctx: &CodeGenContext<'ctx, '_>,
+        op: IntPredicate,
+        other: Int<'ctx, N>,
+        name: &str,
+    ) -> Int<'ctx, Bool> {
+        let bool_model = IntModel(Bool);
+        let value = ctx.builder.build_int_compare(op, self.value, other.value, name).unwrap();
+        bool_model.believe_value(value)
+    }
+}
--- a/nac3core/src/codegen/model/mod.rs
+++ b/nac3core/src/codegen/model/mod.rs
@ -0,0 +1,12 @@
+mod core;
+mod int;
+mod ptr;
+mod slice;
+mod structure;
+pub mod util;
+
+pub use core::*;
+pub use int::*;
+pub use ptr::*;
+pub use slice::*;
+pub use structure::*;
--- a/nac3core/src/codegen/model/ptr.rs
+++ b/nac3core/src/codegen/model/ptr.rs
@ -0,0 +1,142 @@
+use inkwell::{
+    context::Context,
+    types::{BasicType, BasicTypeEnum, PointerType},
+    values::{IntValue, PointerValue},
+    AddressSpace,
+};
+
+use crate::codegen::CodeGenContext;
+
+use super::*;
+
+#[derive(Debug, Clone, Copy, Default)]
+pub struct PtrModel<Element>(pub Element);
+pub type Ptr<'ctx, Element> = Instance<'ctx, PtrModel<Element>>;
+
+impl<Element: CheckType> CheckType for PtrModel<Element> {
+    fn check_type_impl<'ctx>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &'ctx Context,
+        ty: BasicTypeEnum<'ctx>,
+    ) -> Result<(), super::ModelError> {
+        let Ok(ty) = PointerType::try_from(ty) else {
+            return Err(ModelError(format!("Expecting PointerType, but got {ty:?}")));
+        };
+
+        let elem_ty = ty.get_element_type();
+        let Ok(elem_ty) = BasicTypeEnum::try_from(elem_ty) else {
+            return Err(ModelError(format!(
+                "Expecting pointer element type to be a BasicTypeEnum, but got {elem_ty:?}"
+            )));
+        };
+
+        // TODO: inkwell `get_element_type()` will be deprecated.
+        // Remove the check for `get_element_type()` when the time comes.
+        self.0
+            .check_type_impl(tyctx, ctx, elem_ty)
+            .map_err(|err| err.under_context("a PointerType"))?;
+
+        Ok(())
+    }
+}
+
+impl<Element: Model> Model for PtrModel<Element> {
+    type Value<'ctx> = PointerValue<'ctx>;
+    type Type<'ctx> = PointerType<'ctx>;
+
+    fn get_type<'ctx>(&self, tyctx: TypeContext<'ctx>, ctx: &'ctx Context) -> Self::Type<'ctx> {
+        self.0.get_type(tyctx, ctx).ptr_type(AddressSpace::default())
+    }
+}
+
+impl<Element: Model> PtrModel<Element> {
+    /// Return a ***constant*** nullptr.
+    pub fn nullptr<'ctx>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &'ctx Context,
+    ) -> Ptr<'ctx, Element> {
+        let ptr = self.get_type(tyctx, ctx).const_null();
+        self.believe_value(ptr)
+    }
+
+    pub fn transmute<'ctx>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &CodeGenContext<'ctx, '_>,
+        ptr: PointerValue<'ctx>,
+        name: &str,
+    ) -> Ptr<'ctx, Element> {
+        let ptr = ctx.builder.build_pointer_cast(ptr, self.get_type(tyctx, ctx.ctx), name).unwrap();
+        self.believe_value(ptr)
+    }
+}
+
+impl<'ctx, Element: Model> Ptr<'ctx, Element> {
+    /// Offset the pointer by [`inkwell::builder::Builder::build_in_bounds_gep`].
+    #[must_use]
+    pub fn offset(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &CodeGenContext<'ctx, '_>,
+        offset: IntValue<'ctx>,
+        name: &str,
+    ) -> Ptr<'ctx, Element> {
+        let new_ptr =
+            unsafe { ctx.builder.build_in_bounds_gep(self.value, &[offset], name).unwrap() };
+        self.model.check_value(tyctx, ctx.ctx, new_ptr).unwrap()
+    }
+
+    // Load the `i`-th element (0-based) on the array with [`inkwell::builder::Builder::build_in_bounds_gep`].
+    pub fn ix(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &CodeGenContext<'ctx, '_>,
+        i: IntValue<'ctx>,
+        name: &str,
+    ) -> Instance<'ctx, Element> {
+        self.offset(tyctx, ctx, i, name).load(tyctx, ctx, name)
+    }
+
+    /// Load the value with [`inkwell::builder::Builder::build_load`].
+    pub fn load(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &CodeGenContext<'ctx, '_>,
+        name: &str,
+    ) -> Instance<'ctx, Element> {
+        let value = ctx.builder.build_load(self.value, name).unwrap();
+        self.model.0.check_value(tyctx, ctx.ctx, value).unwrap() // If unwrap() panics, there is a logic error.
+    }
+
+    /// Store a value with [`inkwell::builder::Builder::build_store`].
+    pub fn store(&self, ctx: &CodeGenContext<'ctx, '_>, value: Instance<'ctx, Element>) {
+        ctx.builder.build_store(self.value, value.value).unwrap();
+    }
+
+    /// Return a casted pointer of element type `NewElement` with [`inkwell::builder::Builder::build_pointer_cast`].
+    pub fn transmute<NewElement: Model>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &CodeGenContext<'ctx, '_>,
+        new_model: NewElement,
+        name: &str,
+    ) -> Ptr<'ctx, NewElement> {
+        PtrModel(new_model).transmute(tyctx, ctx, self.value, name)
+    }
+
+    /// Check if the pointer is null with [`inkwell::builder::Builder::build_is_null`].
+    pub fn is_null(&self, ctx: &CodeGenContext<'ctx, '_>, name: &str) -> Int<'ctx, Bool> {
+        let bool_model = IntModel(Bool);
+        let value = ctx.builder.build_is_null(self.value, name).unwrap();
+        bool_model.believe_value(value)
+    }
+
+    /// Check if the pointer is not null with [`inkwell::builder::Builder::build_is_not_null`].
+    pub fn is_not_null(&self, ctx: &CodeGenContext<'ctx, '_>, name: &str) -> Int<'ctx, Bool> {
+        let bool_model = IntModel(Bool);
+        let value = ctx.builder.build_is_not_null(self.value, name).unwrap();
+        bool_model.believe_value(value)
+    }
+}
--- a/nac3core/src/codegen/model/slice.rs
+++ b/nac3core/src/codegen/model/slice.rs
@ -0,0 +1,72 @@
+use crate::codegen::{CodeGenContext, CodeGenerator};
+
+use super::*;
+
+/// A slice - literally just a pointer and a length value.
+///
+/// NOTE: This is NOT a [`Model`].
+pub struct ArraySlice<'ctx, Len: IntKind, Item: Model> {
+    pub base: Ptr<'ctx, Item>,
+    pub len: Int<'ctx, Len>,
+}
+
+impl<'ctx, Len: IntKind, Item: Model> ArraySlice<'ctx, Len, Item> {
+    /// Get the `idx`-nth element of this [`ArraySlice`], but doesn't do an assertion to see if `idx` is out of bounds or not.
+    ///
+    /// Also see [`ArraySlice::ix`].
+    pub fn ix_unchecked(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &CodeGenContext<'ctx, '_>,
+        idx: Int<'ctx, Len>,
+        name: &str,
+    ) -> Ptr<'ctx, Item> {
+        let element_ptr = unsafe {
+            ctx.builder.build_in_bounds_gep(self.base.value, &[idx.value], name).unwrap()
+        };
+        self.base.model.check_value(tyctx, ctx.ctx, element_ptr).unwrap()
+    }
+
+    /// Call [`ArraySlice::ix_unchecked`], but checks if `idx` is in bounds, otherwise a runtime `IndexError` will be thrown.
+    pub fn ix<G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+        idx: Int<'ctx, Len>,
+        name: &str,
+    ) -> Ptr<'ctx, Item> {
+        let tyctx = generator.type_context(ctx.ctx);
+        let len_model = IntModel(Len::default());
+
+        // Assert `0 <= idx < length` and throw an Exception if `idx` is out of bounds
+        let lower_bounded = ctx
+            .builder
+            .build_int_compare(
+                inkwell::IntPredicate::SLE,
+                len_model.constant(tyctx, ctx.ctx, 0).value,
+                idx.value,
+                "lower_bounded",
+            )
+            .unwrap();
+        let upper_bounded = ctx
+            .builder
+            .build_int_compare(
+                inkwell::IntPredicate::SLT,
+                idx.value,
+                self.len.value,
+                "upper_bounded",
+            )
+            .unwrap();
+        let bounded = ctx.builder.build_and(lower_bounded, upper_bounded, "bounded").unwrap();
+        ctx.make_assert(
+            generator,
+            bounded,
+            "0:IndexError",
+            "nac3core LLVM codegen attempting to access out of bounds array index {0}. Must satisfy 0 <= index < {2}",
+            [ Some(idx.value), Some(self.len.value), None],
+            ctx.current_loc
+        );
+
+        self.ix_unchecked(tyctx, ctx, idx, name)
+    }
+}
--- a/nac3core/src/codegen/model/structure.rs
+++ b/nac3core/src/codegen/model/structure.rs
@ -0,0 +1,174 @@
+use std::fmt;
+
+use inkwell::{
+    context::Context,
+    types::{BasicType, BasicTypeEnum, StructType},
+    values::StructValue,
+};
+use itertools::izip;
+
+use crate::codegen::CodeGenContext;
+
+use super::*;
+
+#[derive(Debug, Clone, Copy)]
+pub struct GepField<M: Model> {
+    pub gep_index: u64,
+    pub name: &'static str,
+    pub model: M,
+}
+
+pub trait FieldVisitor {
+    type Field<M: Model + 'static>;
+
+    fn add<M: Model + 'static>(&mut self, name: &'static str) -> Self::Field<M>;
+}
+
+pub struct GepFieldVisitor {
+    gep_index_counter: u64,
+}
+
+impl FieldVisitor for GepFieldVisitor {
+    type Field<M: Model + 'static> = GepField<M>;
+
+    fn add<M: Model + 'static>(&mut self, name: &'static str) -> Self::Field<M> {
+        let gep_index = self.gep_index_counter;
+        self.gep_index_counter += 1;
+        Self::Field { gep_index, name, model: M::default() }
+    }
+}
+
+struct TypeFieldVisitor<'ctx> {
+    tyctx: TypeContext<'ctx>,
+    ctx: &'ctx Context,
+    field_types: Vec<BasicTypeEnum<'ctx>>,
+}
+
+impl<'ctx> FieldVisitor for TypeFieldVisitor<'ctx> {
+    type Field<M: Model + 'static> = ();
+
+    fn add<M: Model + 'static>(&mut self, _name: &'static str) -> Self::Field<M> {
+        self.field_types.push(M::default().get_type(self.tyctx, self.ctx).as_basic_type_enum());
+    }
+}
+
+struct CheckTypeEntry {
+    check_type: Box<dyn CheckType + 'static>,
+    name: &'static str,
+}
+
+struct CheckTypeFieldVisitor<'ctx> {
+    tyctx: TypeContext<'ctx>,
+    ctx: &'ctx Context,
+    check_types: Vec<CheckTypeEntry>,
+}
+
+impl<'ctx> FieldVisitor for CheckTypeFieldVisitor<'ctx> {
+    type Field<M: Model + 'static> = ();
+
+    fn add<M: Model + 'static>(&mut self, name: &'static str) -> Self::Field<M> {
+        self.check_types.push(CheckTypeEntry { check_type: Box::<M>::default(), name });
+    }
+}
+
+pub trait StructKind: fmt::Debug + Clone + Copy + Default {
+    type Fields<F: FieldVisitor>;
+
+    fn visit_fields<F: FieldVisitor>(&self, visitor: &mut F) -> Self::Fields<F>;
+
+    fn fields(&self) -> Self::Fields<GepFieldVisitor> {
+        self.visit_fields(&mut GepFieldVisitor { gep_index_counter: 0 })
+    }
+
+    fn get_struct_type<'ctx>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &'ctx Context,
+    ) -> StructType<'ctx> {
+        let mut visitor = TypeFieldVisitor { tyctx, ctx, field_types: Vec::new() };
+        self.visit_fields(&mut visitor);
+
+        ctx.struct_type(&visitor.field_types, false)
+    }
+}
+
+#[derive(Debug, Clone, Copy, Default)]
+pub struct StructModel<S: StructKind>(pub S);
+pub type Struct<'ctx, S> = Instance<'ctx, StructModel<S>>;
+
+impl<S: StructKind> CheckType for StructModel<S> {
+    fn check_type_impl<'ctx>(
+        &self,
+        tyctx: TypeContext<'ctx>,
+        ctx: &'ctx Context,
+        ty: BasicTypeEnum<'ctx>,
+    ) -> Result<(), ModelError> {
+        let ty = ty.as_basic_type_enum();
+        let Ok(ty) = StructType::try_from(ty) else {
+            return Err(ModelError(format!("Expecting StructType, but got {ty:?}")));
+        };
+
+        let field_types = ty.get_field_types();
+
+        let check_types = {
+            let mut builder = CheckTypeFieldVisitor { tyctx, ctx, check_types: Vec::new() };
+            self.0.visit_fields(&mut builder);
+            builder.check_types
+        };
+
+        if check_types.len() != field_types.len() {
+            return Err(ModelError(format!(
+                "Expecting StructType to have {} field(s), but got {} field(s)",
+                check_types.len(),
+                field_types.len()
+            )));
+        }
+
+        for (field_i, (entry, field_type)) in izip!(check_types, field_types).enumerate() {
+            let field_at = field_i + 1;
+
+            entry.check_type.check_type_impl(tyctx, ctx, field_type).map_err(|err| {
+                err.under_context(format!("struct field #{field_at} '{}'", entry.name).as_str())
+            })?;
+        }
+
+        Ok(())
+    }
+}
+
+impl<S: StructKind> Model for StructModel<S> {
+    type Value<'ctx> = StructValue<'ctx>;
+    type Type<'ctx> = StructType<'ctx>;
+
+    fn get_type<'ctx>(&self, tyctx: TypeContext<'ctx>, ctx: &'ctx Context) -> Self::Type<'ctx> {
+        self.0.get_struct_type(tyctx, ctx)
+    }
+}
+
+impl<'ctx, S: StructKind> Ptr<'ctx, StructModel<S>> {
+    pub fn gep<M, GetField>(
+        &self,
+        ctx: &CodeGenContext<'ctx, '_>,
+        get_field: GetField,
+    ) -> Ptr<'ctx, M>
+    where
+        M: Model,
+        GetField: FnOnce(S::Fields<GepFieldVisitor>) -> GepField<M>,
+    {
+        let field = get_field(self.model.0 .0.fields());
+        let llvm_i32 = ctx.ctx.i32_type(); // must be i32, if its i64 then rust segfaults
+
+        let ptr = unsafe {
+            ctx.builder
+                .build_in_bounds_gep(
+                    self.value,
+                    &[llvm_i32.const_zero(), llvm_i32.const_int(field.gep_index, false)],
+                    field.name,
+                )
+                .unwrap()
+        };
+
+        let ptr_model = PtrModel(field.model);
+        ptr_model.believe_value(ptr)
+    }
+}
--- a/nac3core/src/codegen/model/util.rs
+++ b/nac3core/src/codegen/model/util.rs
@ -0,0 +1,23 @@
+use inkwell::{types::BasicType, values::IntValue};
+
+use crate::codegen::{llvm_intrinsics::call_memcpy_generic, CodeGenContext};
+
+use super::*;
+
+pub fn gen_model_memcpy<'ctx, M: Model>(
+    tyctx: TypeContext<'ctx>,
+    ctx: &CodeGenContext<'ctx, '_>,
+    dst: Ptr<'ctx, M>,
+    src: Ptr<'ctx, M>,
+    num_elements: IntValue<'ctx>,
+    volatile: bool,
+) {
+    let bool_model = IntModel(Bool);
+
+    let itemsize = M::default().get_type(tyctx, ctx.ctx).size_of().unwrap();
+    let totalsize =
+        ctx.builder.build_int_mul(itemsize, num_elements, "model_memcpy_totalsize").unwrap();
+    let is_volatile = bool_model.constant(tyctx, ctx.ctx, u64::from(volatile));
+
+    call_memcpy_generic(ctx, dst.value, src.value, totalsize, is_volatile.value);
+}
--- a/nac3core/src/codegen/numpy.rs
+++ b/nac3core/src/codegen/numpy.rs
--- a/nac3core/src/codegen/numpy_new/broadcast.rs
+++ b/nac3core/src/codegen/numpy_new/broadcast.rs
@ -0,0 +1,113 @@
+use itertools::Itertools;
+
+use crate::{
+    codegen::{
+        irrt::ndarray::broadcast::{
+            call_nac3_ndarray_broadcast_shapes, call_nac3_ndarray_broadcast_to, ShapeEntry,
+        },
+        model::*,
+        numpy_new::util::{create_ndims, extract_ndims},
+        CodeGenContext, CodeGenerator,
+    },
+    typecheck::typedef::Type,
+};
+
+use super::object::NDArrayObject;
+
+#[derive(Debug, Clone)]
+pub struct BroadcastAllResult<'ctx> {
+    /// The statically known `ndims` of the broadcast result.
+    pub ndims: u64,
+    /// The broadcasting shape.
+    pub shape: Ptr<'ctx, IntModel<SizeT>>,
+    /// Broadcasted views on the inputs.
+    ///
+    /// All of them will have `shape` [`BroadcastAllResult::shape`] and
+    /// `ndims` [`BroadcastAllResult::ndims`]. The length of the vector
+    /// is the same as the input.
+    pub ndarrays: Vec<NDArrayObject<'ctx>>,
+}
+
+// TODO: DOCUMENT: Behaves like `np.broadcast()`, except returns results differently.
+pub fn broadcast_all_ndarrays<'ctx, G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    ndarrays: Vec<NDArrayObject<'ctx>>,
+) -> BroadcastAllResult<'ctx> {
+    assert!(!ndarrays.is_empty());
+
+    let tyctx = generator.type_context(ctx.ctx);
+    let sizet_model = IntModel(SizeT);
+    let shape_model = StructModel(ShapeEntry);
+
+    // We can deduce the final ndims statically and immediately.
+    // It should be `max([ ndarray.ndims for ndarray in ndarrays ])`.
+    let broadcast_ndims =
+        ndarrays.iter().map(|ndarray| extract_ndims(&ctx.unifier, ndarray.ndims)).max().unwrap();
+    let broadcast_ndims_ty = create_ndims(&mut ctx.unifier, broadcast_ndims);
+
+    // NOTE: Now prepare before calling `call_nac3_ndarray_broadcast_shapes`
+
+    // Prepare input shape entries
+    let num_shape_entries =
+        sizet_model.constant(tyctx, ctx.ctx, u64::try_from(ndarrays.len()).unwrap());
+    let shape_entries =
+        shape_model.array_alloca(tyctx, ctx, num_shape_entries.value, "shape_entries");
+    for (i, ndarray) in ndarrays.iter().enumerate() {
+        let i = sizet_model.constant(tyctx, ctx.ctx, i as u64).value;
+
+        let this_shape = ndarray.instance.gep(ctx, |f| f.shape).load(tyctx, ctx, "this_shape");
+        let this_ndims = ndarray.instance.gep(ctx, |f| f.ndims).load(tyctx, ctx, "this_ndims");
+
+        let shape_entry = shape_entries.offset(tyctx, ctx, i, "shape_entry");
+        shape_entry.gep(ctx, |f| f.shape).store(ctx, this_shape);
+        shape_entry.gep(ctx, |f| f.ndims).store(ctx, this_ndims);
+    }
+
+    // Prepare destination
+    let dst_ndims = sizet_model.constant(tyctx, ctx.ctx, broadcast_ndims);
+    let dst_shape = sizet_model.array_alloca(tyctx, ctx, dst_ndims.value, "dst_shape");
+
+    call_nac3_ndarray_broadcast_shapes(
+        generator,
+        ctx,
+        num_shape_entries,
+        shape_entries,
+        dst_ndims,
+        dst_shape,
+    );
+
+    // Now that we know about the broadcasting shape, broadcast all the inputs.
+
+    // Broadcast all the inputs to shape `dst_shape`
+    let broadcasted_ndarrays = ndarrays
+        .into_iter()
+        .map(|ndarray| ndarray.broadcast_to(generator, ctx, broadcast_ndims_ty, dst_shape))
+        .collect_vec();
+
+    BroadcastAllResult { ndims: broadcast_ndims, shape: dst_shape, ndarrays: broadcasted_ndarrays }
+}
+
+impl<'ctx> NDArrayObject<'ctx> {
+    /// Broadcast an ndarray to a target shape.
+    #[must_use]
+    pub fn broadcast_to<G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+        target_ndims_ty: Type,
+        target_shape: Ptr<'ctx, IntModel<SizeT>>,
+    ) -> Self {
+        // Please see comment in IRRT on how the caller should prepare `dst_ndarray`
+        let dst_ndarray = NDArrayObject::alloca(
+            generator,
+            ctx,
+            target_ndims_ty,
+            self.dtype,
+            "broadcast_ndarray_to_dst",
+        );
+        dst_ndarray.copy_shape(generator, ctx, target_shape);
+        call_nac3_ndarray_broadcast_to(generator, ctx, self.instance, dst_ndarray.instance);
+        dst_ndarray
+    }
+}
--- a/nac3core/src/codegen/numpy_new/factory.rs
+++ b/nac3core/src/codegen/numpy_new/factory.rs
@ -0,0 +1,217 @@
+use inkwell::{
+    types::BasicType,
+    values::{BasicValue, BasicValueEnum, PointerValue},
+    AddressSpace,
+};
+use nac3parser::ast::StrRef;
+
+use crate::{
+    codegen::{
+        model::*,
+        numpy_new::util::{alloca_ndarray, init_ndarray_data_by_alloca, init_ndarray_shape},
+        structure::ndarray::NpArray,
+        util::shape::make_shape_writer,
+        CodeGenContext, CodeGenerator,
+    },
+    symbol_resolver::ValueEnum,
+    toplevel::DefinitionId,
+    typecheck::typedef::{FunSignature, Type},
+};
+
+use super::util::gen_foreach_ndarray_elements;
+
+/// Helper function to create an ndarray with uninitialized values
+///
+/// * `elem_ty` - The [`Type`] of the ndarray elements
+/// * `shape` - The user input shape argument
+/// * `shape_ty` - The [`Type`] of the shape argument
+/// * `name` - LLVM IR name of the returned ndarray
+fn create_empty_ndarray<'ctx, G>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    elem_ty: Type,
+    shape: BasicValueEnum<'ctx>,
+    shape_ty: Type,
+    name: &str,
+) -> Result<Ptr<'ctx, StructModel<NpArray>>, String>
+where
+    G: CodeGenerator + ?Sized,
+{
+    let tyctx = generator.type_context(ctx.ctx);
+    let sizet_model = IntModel(SizeT);
+
+    let shape_writer = make_shape_writer(generator, ctx, shape, shape_ty);
+    let ndims = shape_writer.len;
+
+    let ndarray = alloca_ndarray(generator, ctx, ndims, name);
+    init_ndarray_shape(generator, ctx, ndarray, &shape_writer)?;
+
+    let itemsize = ctx.get_llvm_type(generator, elem_ty).size_of().unwrap();
+    let itemsize = sizet_model.check_value(tyctx, ctx.ctx, itemsize).unwrap();
+    ndarray.gep(ctx, |f| f.itemsize).store(ctx, itemsize);
+
+    // Needs `itemsize` and `shape` initialized
+    init_ndarray_data_by_alloca(generator, ctx, ndarray);
+
+    Ok(ndarray)
+}
+
+/// Helper function to create an ndarray full of a value.
+///
+/// * `elem_ty` - The [`Type`] of the ndarray elements and the fill value
+/// * `shape` - The user input shape argument
+/// * `shape_ty` - The [`Type`] of the shape argument
+/// * `fill_value` - The user specified fill value
+/// * `name` - LLVM IR name of the returned ndarray
+fn create_full_ndarray<'ctx, G>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    elem_ty: Type,
+    shape: BasicValueEnum<'ctx>,
+    shape_ty: Type,
+    fill_value: BasicValueEnum<'ctx>,
+    name: &str,
+) -> Result<Ptr<'ctx, StructModel<NpArray>>, String>
+where
+    G: CodeGenerator + ?Sized,
+{
+    let pndarray = create_empty_ndarray(generator, ctx, elem_ty, shape, shape_ty, name)?;
+    gen_foreach_ndarray_elements(
+        generator,
+        ctx,
+        pndarray,
+        |_generator, ctx, _hooks, _i, pelement| {
+            // Cannot use Model here, fill_value's type is not statically known.
+            let pfill_value_ty = fill_value.get_type().ptr_type(AddressSpace::default());
+            let pelement =
+                ctx.builder.build_pointer_cast(pelement.value, pfill_value_ty, "pelement").unwrap();
+            ctx.builder.build_store(pelement, fill_value).unwrap();
+            Ok(())
+        },
+    )?;
+    Ok(pndarray)
+}
+
+/// Generates LLVM IR for `np.empty`.
+pub fn gen_ndarray_empty<'ctx>(
+    context: &mut CodeGenContext<'ctx, '_>,
+    obj: &Option<(Type, ValueEnum<'ctx>)>,
+    fun: (&FunSignature, DefinitionId),
+    args: &[(Option<StrRef>, ValueEnum<'ctx>)],
+    generator: &mut dyn CodeGenerator,
+) -> Result<PointerValue<'ctx>, String> {
+    assert!(obj.is_none());
+    assert_eq!(args.len(), 1);
+
+    // Parse arguments
+    let shape_ty = fun.0.args[0].ty;
+    let shape = args[0].1.clone().to_basic_value_enum(context, generator, shape_ty)?;
+
+    // Implementation
+    let ndarray_ptr = create_empty_ndarray(
+        generator,
+        context,
+        context.primitives.float,
+        shape,
+        shape_ty,
+        "ndarray",
+    )?;
+    Ok(ndarray_ptr.value)
+}
+
+/// Generates LLVM IR for `np.zeros`.
+pub fn gen_ndarray_zeros<'ctx>(
+    context: &mut CodeGenContext<'ctx, '_>,
+    obj: &Option<(Type, ValueEnum<'ctx>)>,
+    fun: (&FunSignature, DefinitionId),
+    args: &[(Option<StrRef>, ValueEnum<'ctx>)],
+    generator: &mut dyn CodeGenerator,
+) -> Result<PointerValue<'ctx>, String> {
+    assert!(obj.is_none());
+    assert_eq!(args.len(), 1);
+
+    // Parse arguments
+    let shape_ty = fun.0.args[0].ty;
+    let shape = args[0].1.clone().to_basic_value_enum(context, generator, shape_ty)?;
+
+    // Implementation
+    // NOTE: Currently nac3's `np.zeros` is always `float64`.
+    let float64_ty = context.primitives.float;
+    let float64_llvm_type = context.get_llvm_type(generator, float64_ty).into_float_type();
+
+    let ndarray_ptr = create_full_ndarray(
+        generator,
+        context,
+        float64_ty, // `elem_ty` is always `float64`
+        shape,
+        shape_ty,
+        float64_llvm_type.const_zero().as_basic_value_enum(),
+        "ndarray",
+    )?;
+    Ok(ndarray_ptr.value)
+}
+
+/// Generates LLVM IR for `np.ones`.
+pub fn gen_ndarray_ones<'ctx>(
+    context: &mut CodeGenContext<'ctx, '_>,
+    obj: &Option<(Type, ValueEnum<'ctx>)>,
+    fun: (&FunSignature, DefinitionId),
+    args: &[(Option<StrRef>, ValueEnum<'ctx>)],
+    generator: &mut dyn CodeGenerator,
+) -> Result<PointerValue<'ctx>, String> {
+    assert!(obj.is_none());
+    assert_eq!(args.len(), 1);
+
+    // Parse arguments
+    let shape_ty = fun.0.args[0].ty;
+    let shape = args[0].1.clone().to_basic_value_enum(context, generator, shape_ty)?;
+
+    // Implementation
+    // NOTE: Currently nac3's `np.ones` is always `float64`.
+    let float64_ty = context.primitives.float;
+    let float64_llvm_type = context.get_llvm_type(generator, float64_ty).into_float_type();
+
+    let ndarray_ptr = create_full_ndarray(
+        generator,
+        context,
+        float64_ty, // `elem_ty` is always `float64`
+        shape,
+        shape_ty,
+        float64_llvm_type.const_float(1.0).as_basic_value_enum(),
+        "ndarray",
+    )?;
+    Ok(ndarray_ptr.value)
+}
+
+/// Generates LLVM IR for `np.full`.
+pub fn gen_ndarray_full<'ctx>(
+    context: &mut CodeGenContext<'ctx, '_>,
+    obj: &Option<(Type, ValueEnum<'ctx>)>,
+    fun: (&FunSignature, DefinitionId),
+    args: &[(Option<StrRef>, ValueEnum<'ctx>)],
+    generator: &mut dyn CodeGenerator,
+) -> Result<PointerValue<'ctx>, String> {
+    assert!(obj.is_none());
+    assert_eq!(args.len(), 2);
+
+    // Parse argument #1 shape
+    let shape_ty = fun.0.args[0].ty;
+    let shape_arg = args[0].1.clone().to_basic_value_enum(context, generator, shape_ty)?;
+
+    // Parse argument #2 fill_value
+    let fill_value_ty = fun.0.args[1].ty;
+    let fill_value_arg =
+        args[1].1.clone().to_basic_value_enum(context, generator, fill_value_ty)?;
+
+    // Implementation
+    let ndarray_ptr = create_full_ndarray(
+        generator,
+        context,
+        fill_value_ty,
+        shape_arg,
+        shape_ty,
+        fill_value_arg,
+        "ndarray",
+    )?;
+    Ok(ndarray_ptr.value)
+}
--- a/nac3core/src/codegen/numpy_new/indexing.rs
+++ b/nac3core/src/codegen/numpy_new/indexing.rs
@ -0,0 +1,76 @@
+use crate::{
+    codegen::{
+        irrt::ndarray::indexing::{call_nac3_ndarray_index, RustNDIndex},
+        model::*,
+        CodeGenContext, CodeGenerator,
+    },
+    typecheck::typedef::{Type, Unifier},
+};
+
+use super::{
+    object::{NDArrayObject, ScalarObject, ScalarOrNDArray},
+    util::{create_ndims, extract_ndims},
+};
+
+impl<'ctx> NDArrayObject<'ctx> {
+    pub fn deduce_ndims_after_indexing_with(
+        &self,
+        unifier: &mut Unifier,
+        indexes: &[RustNDIndex<'ctx>],
+    ) -> Type {
+        let ndims = extract_ndims(unifier, self.ndims);
+        let new_ndims = RustNDIndex::deduce_ndims_after_indexing(indexes, ndims);
+        create_ndims(unifier, new_ndims)
+    }
+
+    #[must_use]
+    pub fn index_always_ndarray<G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+        indexes: &[RustNDIndex<'ctx>],
+        name: &str,
+    ) -> Self {
+        let tyctx = generator.type_context(ctx.ctx);
+
+        let dst_ndims = self.deduce_ndims_after_indexing_with(&mut ctx.unifier, indexes);
+        let dst_ndarray = NDArrayObject::alloca(generator, ctx, dst_ndims, self.dtype, name);
+
+        let (num_indexes, indexes) = RustNDIndex::alloca_ndindexes(tyctx, ctx, indexes);
+        call_nac3_ndarray_index(
+            generator,
+            ctx,
+            num_indexes,
+            indexes,
+            self.instance,
+            dst_ndarray.instance,
+        );
+
+        dst_ndarray
+    }
+
+    pub fn index<G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+        indexes: &[RustNDIndex<'ctx>],
+        name: &str,
+    ) -> ScalarOrNDArray<'ctx> {
+        let tyctx = generator.type_context(ctx.ctx);
+        let sizet_model = IntModel(SizeT);
+
+        let subndarray = self.index_always_ndarray(generator, ctx, indexes, name);
+        if subndarray.is_unsized(&ctx.unifier) {
+            // TODO: This actually never fails, don't use the `checked_` version.
+            let value = subndarray.checked_get_nth_element(
+                generator,
+                ctx,
+                sizet_model.const_0(tyctx, ctx.ctx),
+                name,
+            );
+            ScalarOrNDArray::Scalar(ScalarObject { dtype: self.dtype, value })
+        } else {
+            ScalarOrNDArray::NDArray(subndarray)
+        }
+    }
+}
--- a/nac3core/src/codegen/numpy_new/mod.rs
+++ b/nac3core/src/codegen/numpy_new/mod.rs
@ -0,0 +1,6 @@
+pub mod broadcast;
+pub mod factory;
+pub mod indexing;
+pub mod object;
+pub mod util;
+pub mod view;
--- a/nac3core/src/codegen/numpy_new/object.rs
+++ b/nac3core/src/codegen/numpy_new/object.rs
@ -0,0 +1,69 @@
+use inkwell::values::{BasicValue, BasicValueEnum};
+
+use crate::{
+    codegen::{model::*, structure::ndarray::NpArray, CodeGenContext},
+    toplevel::numpy::unpack_ndarray_var_tys,
+    typecheck::typedef::{Type, TypeEnum},
+};
+
+/// An LLVM ndarray instance with its typechecker [`Type`]s.
+#[derive(Debug, Clone, Copy)]
+pub struct NDArrayObject<'ctx> {
+    pub dtype: Type,
+    pub ndims: Type,
+    pub instance: Ptr<'ctx, StructModel<NpArray>>,
+}
+
+/// An LLVM numpy scalar with its [`Type`].
+#[derive(Debug, Clone, Copy)]
+pub struct ScalarObject<'ctx> {
+    pub dtype: Type,
+    pub value: BasicValueEnum<'ctx>,
+}
+
+#[derive(Debug, Clone, Copy)]
+pub enum ScalarOrNDArray<'ctx> {
+    Scalar(ScalarObject<'ctx>),
+    NDArray(NDArrayObject<'ctx>),
+}
+
+impl<'ctx> ScalarOrNDArray<'ctx> {
+    /// Get the underlying [`BasicValueEnum<'ctx>`] of this [`ScalarOrNDArray`].
+    #[must_use]
+    pub fn to_basic_value_enum(self) -> BasicValueEnum<'ctx> {
+        match self {
+            ScalarOrNDArray::Scalar(scalar) => scalar.value,
+            ScalarOrNDArray::NDArray(ndarray) => ndarray.instance.value.as_basic_value_enum(),
+        }
+    }
+}
+
+impl<'ctx> From<ScalarOrNDArray<'ctx>> for BasicValueEnum<'ctx> {
+    fn from(input: ScalarOrNDArray<'ctx>) -> BasicValueEnum<'ctx> {
+        input.to_basic_value_enum()
+    }
+}
+
+/// Split an [`BasicValueEnum<'ctx>`] into a [`ScalarOrNDArray`] depending
+/// on its [`Type`].
+pub fn split_scalar_or_ndarray<'ctx>(
+    tyctx: TypeContext<'ctx>,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    input: BasicValueEnum<'ctx>,
+    input_ty: Type,
+) -> ScalarOrNDArray<'ctx> {
+    let pndarray_model = PtrModel(StructModel(NpArray));
+
+    let input_ty_enum = ctx.unifier.get_ty(input_ty);
+    match &*input_ty_enum {
+        TypeEnum::TObj { obj_id, .. }
+            if *obj_id == ctx.primitives.ndarray.obj_id(&ctx.unifier).unwrap() =>
+        {
+            let value = pndarray_model.check_value(tyctx, ctx.ctx, input).unwrap();
+            let (dtype, ndims) = unpack_ndarray_var_tys(&mut ctx.unifier, input_ty);
+
+            ScalarOrNDArray::NDArray(NDArrayObject { dtype, ndims, instance: value })
+        }
+        _ => ScalarOrNDArray::Scalar(ScalarObject { dtype: input_ty, value: input }),
+    }
+}
--- a/nac3core/src/codegen/numpy_new/util.rs
+++ b/nac3core/src/codegen/numpy_new/util.rs
@ -0,0 +1,328 @@
+use inkwell::{
+    types::BasicType,
+    values::{BasicValueEnum, PointerValue},
+    AddressSpace,
+};
+use util::gen_model_memcpy;
+
+use crate::{
+    codegen::{
+        irrt::ndarray::basic::{
+            call_nac3_ndarray_copy_data, call_nac3_ndarray_get_nth_pelement,
+            call_nac3_ndarray_is_c_contiguous, call_nac3_ndarray_nbytes,
+            call_nac3_ndarray_set_strides_by_shape, call_nac3_ndarray_size,
+            call_nac3_ndarray_util_assert_shape_no_negative,
+        },
+        model::*,
+        stmt::BreakContinueHooks,
+        structure::ndarray::NpArray,
+        util::{array_writer::ArrayWriter, control::gen_model_for},
+        CodeGenContext, CodeGenerator,
+    },
+    symbol_resolver::SymbolValue,
+    typecheck::typedef::{Type, TypeEnum, Unifier},
+};
+
+use super::object::{NDArrayObject, ScalarOrNDArray};
+
+/// Extract an ndarray's `ndims` [type][`Type`] in `u64`. Panic if not possible.
+#[must_use]
+pub fn extract_ndims(unifier: &Unifier, ndims_ty: Type) -> u64 {
+    let ndims_ty_enum = unifier.get_ty_immutable(ndims_ty);
+    let TypeEnum::TLiteral { values, .. } = &*ndims_ty_enum else {
+        panic!("ndims_ty should be a TLiteral");
+    };
+
+    assert_eq!(values.len(), 1, "ndims_ty TLiteral should only contain 1 value");
+
+    let ndims = values[0].clone();
+    u64::try_from(ndims).unwrap()
+}
+
+/// Return an ndarray's `ndims` as a typechecker [`Type`] from its `u64` value.
+pub fn create_ndims(unifier: &mut Unifier, ndims: u64) -> Type {
+    unifier.get_fresh_literal(vec![SymbolValue::U64(ndims)], None)
+}
+
+/// Allocate an ndarray on the stack given its `ndims`.
+///
+/// `shape` and `strides` will be automatically allocated on the stack.
+///
+/// The returned ndarray's content will be:
+/// - `data`: `nullptr`
+/// - `itemsize`: **uninitialized** value
+/// - `ndims`: initialized value, set to the input `ndims`
+/// - `shape`: initialized pointer to an allocated stack with **uninitialized** values
+/// - `strides`: initialized pointer to an allocated stack with **uninitialized** values
+pub fn alloca_ndarray<'ctx, G>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    ndims: Int<'ctx, SizeT>,
+    name: &str,
+) -> Ptr<'ctx, StructModel<NpArray>>
+where
+    G: CodeGenerator + ?Sized,
+{
+    let tyctx = generator.type_context(ctx.ctx);
+
+    let sizet_model = IntModel(SizeT);
+    let ndarray_model = StructModel(NpArray);
+    let ndarray_data_model = PtrModel(IntModel(Byte));
+
+    // Setup ndarray
+    let ndarray_ptr = ndarray_model.alloca(tyctx, ctx, name);
+    let shape = sizet_model.array_alloca(tyctx, ctx, ndims.value, "shape");
+    let strides = sizet_model.array_alloca(tyctx, ctx, ndims.value, "strides");
+
+    ndarray_ptr.gep(ctx, |f| f.data).store(ctx, ndarray_data_model.nullptr(tyctx, ctx.ctx));
+    ndarray_ptr.gep(ctx, |f| f.ndims).store(ctx, ndims);
+    ndarray_ptr.gep(ctx, |f| f.shape).store(ctx, shape);
+    ndarray_ptr.gep(ctx, |f| f.strides).store(ctx, strides);
+
+    ndarray_ptr
+}
+
+/// Initialize an ndarray's `shape` and asserts on.
+/// `shape`'s values and prohibit illegal inputs like negative dimensions.
+pub fn init_ndarray_shape<'ctx, G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    pndarray: Ptr<'ctx, StructModel<NpArray>>,
+    shape_writer: &ArrayWriter<'ctx, G, SizeT, IntModel<SizeT>>,
+) -> Result<(), String> {
+    let tyctx = generator.type_context(ctx.ctx);
+    let shape = pndarray.gep(ctx, |f| f.shape).load(tyctx, ctx, "shape");
+    (shape_writer.write)(generator, ctx, shape)?;
+    call_nac3_ndarray_util_assert_shape_no_negative(generator, ctx, shape_writer.len, shape);
+    Ok(())
+}
+
+/// Initialize an ndarray's `data` by allocating a buffer on the stack.
+/// The allocated data buffer is considered to be *owned* by the ndarray.
+///
+/// `strides` of the ndarray will also be updated with `set_strides_by_shape`.
+///
+/// `shape` and `itemsize` of the ndarray ***must*** be initialized first.
+pub fn init_ndarray_data_by_alloca<'ctx, G: CodeGenerator + ?Sized>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    pndarray: Ptr<'ctx, StructModel<NpArray>>,
+) {
+    let tyctx = generator.type_context(ctx.ctx);
+    let ndarray_data_model = IntModel(Byte);
+
+    let nbytes = call_nac3_ndarray_nbytes(generator, ctx, pndarray);
+    let data = ndarray_data_model.array_alloca(tyctx, ctx, nbytes.value, "data");
+    pndarray.gep(ctx, |f| f.data).store(ctx, data);
+    call_nac3_ndarray_set_strides_by_shape(generator, ctx, pndarray);
+}
+
+/// Iterate through all elements in an ndarray.
+///
+/// `body` is given the index of an element and an opaque pointer (as an `uint8_t*`, you might want to cast it) to the element.
+///
+/// Short-circuiting is possible with the given [`BreakContinueHooks`].
+pub fn gen_foreach_ndarray_elements<'ctx, G, F>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    pndarray: Ptr<'ctx, StructModel<NpArray>>,
+    body: F,
+) -> Result<(), String>
+where
+    G: CodeGenerator + ?Sized,
+    F: Fn(
+        &mut G,
+        &mut CodeGenContext<'ctx, '_>,
+        BreakContinueHooks<'ctx>,
+        Int<'ctx, SizeT>,
+        Ptr<'ctx, IntModel<Byte>>,
+    ) -> Result<(), String>,
+{
+    // TODO: Make this more efficient - use a special NDArray iterator?
+
+    let tyctx = generator.type_context(ctx.ctx);
+
+    let sizet_model = IntModel(SizeT);
+    let size = call_nac3_ndarray_size(generator, ctx, pndarray);
+
+    gen_model_for(
+        generator,
+        ctx,
+        sizet_model.const_0(tyctx, ctx.ctx),
+        size,
+        sizet_model.const_1(tyctx, ctx.ctx),
+        |generator, ctx, hooks, index| {
+            let pelement = call_nac3_ndarray_get_nth_pelement(generator, ctx, pndarray, index);
+            body(generator, ctx, hooks, index, pelement)
+        },
+    )
+}
+
+impl<'ctx> ScalarOrNDArray<'ctx> {
+    /// Convert `input` to an ndarray - behaves like `np.asarray`.
+    pub fn as_ndarray<G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+    ) -> NDArrayObject<'ctx> {
+        match self {
+            ScalarOrNDArray::NDArray(ndarray) => *ndarray,
+            ScalarOrNDArray::Scalar(scalar) => {
+                let tyctx = generator.type_context(ctx.ctx);
+                let pbyte_model = PtrModel(IntModel(Byte));
+
+                // We have to put the value on the stack to get a data pointer.
+                let data =
+                    ctx.builder.build_alloca(scalar.value.get_type(), "as_ndarray_scalar").unwrap();
+                ctx.builder.build_store(data, scalar.value).unwrap();
+                let data = pbyte_model.transmute(tyctx, ctx, data, "data");
+
+                let ndims_ty = create_ndims(&mut ctx.unifier, 0);
+                let ndarray = NDArrayObject::alloca(
+                    generator,
+                    ctx,
+                    ndims_ty,
+                    scalar.dtype,
+                    "scalar_as_ndarray",
+                );
+                ndarray.instance.gep(ctx, |f| f.data).store(ctx, data);
+
+                // No need to initialize/setup strides or shapes - because `ndims` is 0.
+                // So we only have to set `data`, `itemsize`, and `ndims = 0`.
+
+                ndarray
+            }
+        }
+    }
+}
+
+impl<'ctx> NDArrayObject<'ctx> {
+    pub fn alloca<G: CodeGenerator + ?Sized>(
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+        ndims: Type,
+        dtype: Type,
+        name: &str,
+    ) -> Self {
+        let tyctx = generator.type_context(ctx.ctx);
+        let sizet_model = IntModel(SizeT);
+
+        let ndims_int = sizet_model.constant(tyctx, ctx.ctx, extract_ndims(&ctx.unifier, ndims));
+        let instance = alloca_ndarray(generator, ctx, ndims_int, name);
+
+        // Set itemsize
+        let dtype_ty = ctx.get_llvm_type(generator, dtype);
+        let itemsize = dtype_ty.size_of().unwrap();
+        let itemsize = sizet_model.s_extend_or_bit_cast(tyctx, ctx, itemsize, "itemsize");
+        instance.gep(ctx, |f| f.itemsize).store(ctx, itemsize);
+
+        NDArrayObject { dtype, ndims, instance }
+    }
+
+    pub fn copy_shape<G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+        src_shape: Ptr<'ctx, IntModel<SizeT>>,
+    ) {
+        let tyctx = generator.type_context(ctx.ctx);
+        let sizet_model = IntModel(SizeT);
+
+        let self_shape = self.instance.gep(ctx, |f| f.shape).load(tyctx, ctx, "self_shape");
+        let ndims_int =
+            sizet_model.constant(tyctx, ctx.ctx, extract_ndims(&ctx.unifier, self.ndims));
+        gen_model_memcpy(tyctx, ctx, self_shape, src_shape, ndims_int.value, false);
+    }
+
+    pub fn copy_shape_from<G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+        src_ndarray: NDArrayObject<'ctx>,
+    ) {
+        let tyctx = generator.type_context(ctx.ctx);
+        let src_shape = src_ndarray.instance.gep(ctx, |f| f.shape).load(tyctx, ctx, "src_shape");
+        self.copy_shape(generator, ctx, src_shape);
+    }
+
+    pub fn update_strides_by_shape<G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+    ) {
+        call_nac3_ndarray_set_strides_by_shape(generator, ctx, self.instance);
+    }
+
+    pub fn checked_get_nth_pelement<G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+        i: Int<'ctx, SizeT>,
+        name: &str,
+    ) -> PointerValue<'ctx> {
+        let elem_ty = ctx.get_llvm_type(generator, self.dtype);
+
+        let p = call_nac3_ndarray_get_nth_pelement(generator, ctx, self.instance, i);
+        ctx.builder
+            .build_pointer_cast(p.value, elem_ty.ptr_type(AddressSpace::default()), name)
+            .unwrap()
+    }
+
+    pub fn checked_get_nth_element<G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+        i: Int<'ctx, SizeT>,
+        name: &str,
+    ) -> BasicValueEnum<'ctx> {
+        let pelement = self.checked_get_nth_pelement(generator, ctx, i, "pelement");
+        ctx.builder.build_load(pelement, name).unwrap()
+    }
+
+    #[must_use]
+    pub fn is_unsized(&self, unifier: &Unifier) -> bool {
+        extract_ndims(unifier, self.ndims) == 0
+    }
+
+    pub fn size<G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+    ) -> Int<'ctx, SizeT> {
+        call_nac3_ndarray_size(generator, ctx, self.instance)
+    }
+
+    pub fn nbytes<G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+    ) -> Int<'ctx, SizeT> {
+        call_nac3_ndarray_nbytes(generator, ctx, self.instance)
+    }
+
+    pub fn is_c_contiguous<G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+    ) -> Int<'ctx, Bool> {
+        call_nac3_ndarray_is_c_contiguous(generator, ctx, self.instance)
+    }
+
+    pub fn alloca_owned_data<G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+    ) {
+        init_ndarray_data_by_alloca(generator, ctx, self.instance);
+    }
+
+    pub fn copy_data_from<G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+        src: NDArrayObject<'ctx>,
+    ) {
+        assert!(ctx.unifier.unioned(self.dtype, src.dtype), "self and src dtype should match");
+        call_nac3_ndarray_copy_data(generator, ctx, src.instance, self.instance);
+    }
+}
--- a/nac3core/src/codegen/numpy_new/view.rs
+++ b/nac3core/src/codegen/numpy_new/view.rs
@ -0,0 +1,114 @@
+use inkwell::values::PointerValue;
+use nac3parser::ast::StrRef;
+
+use crate::{
+    codegen::{
+        irrt::ndarray::reshape::call_nac3_ndarray_resolve_and_check_new_shape,
+        model::*,
+        numpy_new::{object::split_scalar_or_ndarray, util::extract_ndims},
+        util::shape::make_shape_writer,
+        CodeGenContext, CodeGenerator,
+    },
+    symbol_resolver::ValueEnum,
+    toplevel::{numpy::unpack_ndarray_var_tys, DefinitionId},
+    typecheck::typedef::{FunSignature, Type},
+};
+
+use super::object::NDArrayObject;
+
+impl<'ctx> NDArrayObject<'ctx> {
+    #[must_use]
+    pub fn reshape_or_copy<G: CodeGenerator + ?Sized>(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+        new_ndims: Type,
+        new_shape: Ptr<'ctx, IntModel<SizeT>>,
+    ) -> Self {
+        let tyctx = generator.type_context(ctx.ctx);
+
+        let current_bb = ctx.builder.get_insert_block().unwrap();
+        let then_bb = ctx.ctx.insert_basic_block_after(current_bb, "then_bb");
+        let else_bb = ctx.ctx.insert_basic_block_after(then_bb, "else_bb");
+        let end_bb = ctx.ctx.insert_basic_block_after(else_bb, "end_bb");
+
+        let dst_ndarray =
+            NDArrayObject::alloca(generator, ctx, new_ndims, self.dtype, "reshaped_ndarray");
+        dst_ndarray.copy_shape(generator, ctx, new_shape);
+        dst_ndarray.update_strides_by_shape(generator, ctx);
+
+        let is_c_contiguous = self.is_c_contiguous(generator, ctx);
+        ctx.builder.build_conditional_branch(is_c_contiguous.value, then_bb, else_bb).unwrap();
+
+        // Inserting into then_bb: reshape is possible without copying
+        ctx.builder.position_at_end(then_bb);
+        dst_ndarray
+            .instance
+            .gep(ctx, |f| f.data)
+            .store(ctx, dst_ndarray.instance.gep(ctx, |f| f.data).load(tyctx, ctx, "data"));
+        ctx.builder.build_unconditional_branch(end_bb).unwrap();
+
+        // Inserting into else_bb: reshape is impossible without copying
+        ctx.builder.position_at_end(else_bb);
+        dst_ndarray.alloca_owned_data(generator, ctx);
+        dst_ndarray.copy_data_from(generator, ctx, *self);
+        ctx.builder.build_unconditional_branch(end_bb).unwrap();
+
+        // Reposition for continuation
+        ctx.builder.position_at_end(end_bb);
+
+        dst_ndarray
+    }
+}
+
+/// Generates LLVM IR for `np.reshape`.
+pub fn gen_ndarray_reshape<'ctx>(
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    obj: &Option<(Type, ValueEnum<'ctx>)>,
+    fun: (&FunSignature, DefinitionId),
+    args: &[(Option<StrRef>, ValueEnum<'ctx>)],
+    generator: &mut dyn CodeGenerator,
+) -> Result<PointerValue<'ctx>, String> {
+    assert!(obj.is_none());
+    assert_eq!(args.len(), 2);
+
+    // Parse argument #1 input
+    let input_ty = fun.0.args[0].ty;
+    let input_arg = args[0].1.clone().to_basic_value_enum(ctx, generator, input_ty)?;
+
+    // Parse argument #2 shape
+    let shape_ty = fun.0.args[1].ty;
+    let shape_arg = args[1].1.clone().to_basic_value_enum(ctx, generator, shape_ty)?;
+
+    // Define models
+    let tyctx = generator.type_context(ctx.ctx);
+    let sizet_model = IntModel(SizeT);
+
+    // Extract reshaped_ndims
+    let (_, reshaped_ndims) = unpack_ndarray_var_tys(&mut ctx.unifier, fun.0.ret);
+    let reshaped_ndims_int = extract_ndims(&ctx.unifier, reshaped_ndims);
+
+    // Process `input`
+    let ndarray =
+        split_scalar_or_ndarray(tyctx, ctx, input_arg, input_ty).as_ndarray(generator, ctx);
+
+    // Process the shape input from user and resolve negative indices
+    let new_shape = make_shape_writer(generator, ctx, shape_arg, shape_ty).alloca_array_and_write(
+        generator,
+        ctx,
+        "new_shape",
+    )?;
+    let size = ndarray.size(generator, ctx);
+    call_nac3_ndarray_resolve_and_check_new_shape(
+        generator,
+        ctx,
+        size,
+        sizet_model.constant(tyctx, ctx.ctx, reshaped_ndims_int),
+        new_shape,
+    );
+
+    // Reshape
+    let reshaped_ndarray = ndarray.reshape_or_copy(generator, ctx, reshaped_ndims, new_shape);
+
+    Ok(reshaped_ndarray.instance.value)
+}
--- a/nac3core/src/codegen/stmt.rs
+++ b/nac3core/src/codegen/stmt.rs
@ -1,8 +1,11 @@
+use super::model::*;
+use super::structure::cslice::CSlice;
 use super::{
    super::symbol_resolver::ValueEnum,
    expr::destructure_range,
    irrt::{handle_slice_indices, list_slice_assignment},
-    CodeGenContext, CodeGenerator,
+    structure::exception::Exception,
+    CodeGenContext, CodeGenerator, Int32, IntModel, Ptr, StructModel,
 };
 use crate::{
    codegen::{
@ -206,6 +209,7 @@ pub fn gen_assign<'ctx, G: CodeGenerator>(
    ctx: &mut CodeGenContext<'ctx, '_>,
    target: &Expr<Option<Type>>,
    value: ValueEnum<'ctx>,
+    value_ty: Type,
 ) -> Result<(), String> {
    let llvm_usize = generator.get_size_type(ctx.ctx);

@ -222,7 +226,7 @@ pub fn gen_assign<'ctx, G: CodeGenerator>(
                    .builder
                    .build_extract_value(v, u32::try_from(i).unwrap(), "struct_elem")
                    .unwrap();
-                generator.gen_assign(ctx, elt, v.into())?;
+                generator.gen_assign(ctx, elt, v.into(), value_ty)?;
            }
        }
        ExprKind::Subscript { value: ls, slice, .. }
@ -431,7 +435,7 @@ pub fn gen_for<G: CodeGenerator>(
            .map(BasicValueEnum::into_int_value)
            .unwrap();
        let val = ctx.build_gep_and_load(arr_ptr, &[index], Some("val"));
-        generator.gen_assign(ctx, target, val.into())?;
+        generator.gen_assign(ctx, target, val.into(), ctx.primitives.int32)?;
        generator.gen_block(ctx, body.iter())?;
    }

@ -494,6 +498,7 @@ pub struct BreakContinueHooks<'ctx> {
 pub fn gen_for_callback<'ctx, 'a, G, I, InitFn, CondFn, BodyFn, UpdateFn>(
    generator: &mut G,
    ctx: &mut CodeGenContext<'ctx, 'a>,
+    label: Option<&str>,
    init: InitFn,
    cond: CondFn,
    body: BodyFn,
@ -504,18 +509,24 @@ where
    I: Clone,
    InitFn: FnOnce(&mut G, &mut CodeGenContext<'ctx, 'a>) -> Result<I, String>,
    CondFn: FnOnce(&mut G, &mut CodeGenContext<'ctx, 'a>, I) -> Result<IntValue<'ctx>, String>,
-    BodyFn:
-        FnOnce(&mut G, &mut CodeGenContext<'ctx, 'a>, BreakContinueHooks, I) -> Result<(), String>,
+    BodyFn: FnOnce(
+        &mut G,
+        &mut CodeGenContext<'ctx, 'a>,
+        BreakContinueHooks<'ctx>,
+        I,
+    ) -> Result<(), String>,
    UpdateFn: FnOnce(&mut G, &mut CodeGenContext<'ctx, 'a>, I) -> Result<(), String>,
 {
+    let label = label.unwrap_or("for");
+
    let current_bb = ctx.builder.get_insert_block().unwrap();
-    let init_bb = ctx.ctx.insert_basic_block_after(current_bb, "for.init");
+    let init_bb = ctx.ctx.insert_basic_block_after(current_bb, &format!("{label}.init"));
    // The BB containing the loop condition check
-    let cond_bb = ctx.ctx.insert_basic_block_after(init_bb, "for.cond");
-    let body_bb = ctx.ctx.insert_basic_block_after(cond_bb, "for.body");
+    let cond_bb = ctx.ctx.insert_basic_block_after(init_bb, &format!("{label}.cond"));
+    let body_bb = ctx.ctx.insert_basic_block_after(cond_bb, &format!("{label}.body"));
    // The BB containing the increment expression
-    let update_bb = ctx.ctx.insert_basic_block_after(body_bb, "for.update");
-    let cont_bb = ctx.ctx.insert_basic_block_after(update_bb, "for.end");
+    let update_bb = ctx.ctx.insert_basic_block_after(body_bb, &format!("{label}.update"));
+    let cont_bb = ctx.ctx.insert_basic_block_after(update_bb, &format!("{label}.end"));

    // store loop bb information and restore it later
    let loop_bb = ctx.loop_target.replace((update_bb, cont_bb));
@ -572,6 +583,7 @@ where
 pub fn gen_for_callback_incrementing<'ctx, 'a, G, BodyFn>(
    generator: &mut G,
    ctx: &mut CodeGenContext<'ctx, 'a>,
+    label: Option<&str>,
    init_val: IntValue<'ctx>,
    max_val: (IntValue<'ctx>, bool),
    body: BodyFn,
@ -582,7 +594,7 @@ where
    BodyFn: FnOnce(
        &mut G,
        &mut CodeGenContext<'ctx, 'a>,
-        BreakContinueHooks,
+        BreakContinueHooks<'ctx>,
        IntValue<'ctx>,
    ) -> Result<(), String>,
 {
@ -591,6 +603,7 @@ where
    gen_for_callback(
        generator,
        ctx,
+        label,
        |generator, ctx| {
            let i_addr = generator.gen_var_alloc(ctx, init_val_t.into(), None)?;
            ctx.builder.build_store(i_addr, init_val).unwrap();
@ -642,9 +655,11 @@ where
 /// - `step_fn`: A lambda of IR statements that retrieves the `step` value of the  `range`-like
 /// iterable. This value will be extended to the size of `start`.
 /// - `body_fn`: A lambda of IR statements within the loop body.
+#[allow(clippy::too_many_arguments)]
 pub fn gen_for_range_callback<'ctx, 'a, G, StartFn, StopFn, StepFn, BodyFn>(
    generator: &mut G,
    ctx: &mut CodeGenContext<'ctx, 'a>,
+    label: Option<&str>,
    is_unsigned: bool,
    start_fn: StartFn,
    (stop_fn, stop_inclusive): (StopFn, bool),
@ -656,13 +671,19 @@ where
    StartFn: Fn(&mut G, &mut CodeGenContext<'ctx, 'a>) -> Result<IntValue<'ctx>, String>,
    StopFn: Fn(&mut G, &mut CodeGenContext<'ctx, 'a>) -> Result<IntValue<'ctx>, String>,
    StepFn: Fn(&mut G, &mut CodeGenContext<'ctx, 'a>) -> Result<IntValue<'ctx>, String>,
-    BodyFn: FnOnce(&mut G, &mut CodeGenContext<'ctx, 'a>, IntValue<'ctx>) -> Result<(), String>,
+    BodyFn: FnOnce(
+        &mut G,
+        &mut CodeGenContext<'ctx, 'a>,
+        BreakContinueHooks,
+        IntValue<'ctx>,
+    ) -> Result<(), String>,
 {
    let init_val_t = start_fn(generator, ctx).map(IntValue::get_type).unwrap();

    gen_for_callback(
        generator,
        ctx,
+        label,
        |generator, ctx| {
            let i_addr = generator.gen_var_alloc(ctx, init_val_t.into(), None)?;

@ -720,10 +741,10 @@ where

            Ok(cond)
        },
-        |generator, ctx, _, (i_addr, _)| {
+        |generator, ctx, hooks, (i_addr, _)| {
            let i = ctx.builder.build_load(i_addr, "").map(BasicValueEnum::into_int_value).unwrap();

-            body_fn(generator, ctx, i)
+            body_fn(generator, ctx, hooks, i)
        },
        |generator, ctx, (i_addr, _)| {
            let i = ctx.builder.build_load(i_addr, "").map(BasicValueEnum::into_int_value).unwrap();
@ -1113,47 +1134,37 @@ pub fn exn_constructor<'ctx>(
 pub fn gen_raise<'ctx, G: CodeGenerator + ?Sized>(
    generator: &mut G,
    ctx: &mut CodeGenContext<'ctx, '_>,
-    exception: Option<&BasicValueEnum<'ctx>>,
+    exception: Option<Ptr<'ctx, StructModel<Exception>>>,
    loc: Location,
 ) {
-    if let Some(exception) = exception {
-        unsafe {
-            let int32 = ctx.ctx.i32_type();
-            let zero = int32.const_zero();
-            let exception = exception.into_pointer_value();
-            let file_ptr = ctx
-                .builder
-                .build_in_bounds_gep(exception, &[zero, int32.const_int(1, false)], "file_ptr")
-                .unwrap();
-            let filename = ctx.gen_string(generator, loc.file.0);
-            ctx.builder.build_store(file_ptr, filename).unwrap();
-            let row_ptr = ctx
-                .builder
-                .build_in_bounds_gep(exception, &[zero, int32.const_int(2, false)], "row_ptr")
-                .unwrap();
-            ctx.builder.build_store(row_ptr, int32.const_int(loc.row as u64, false)).unwrap();
-            let col_ptr = ctx
-                .builder
-                .build_in_bounds_gep(exception, &[zero, int32.const_int(3, false)], "col_ptr")
-                .unwrap();
-            ctx.builder.build_store(col_ptr, int32.const_int(loc.column as u64, false)).unwrap();
+    if let Some(pexn) = exception {
+        let type_context = generator.type_context(ctx.ctx);
+        let i32_model = IntModel(Int32);
+        let cslice_model = StructModel(CSlice);

-            let current_fun = ctx.builder.get_insert_block().unwrap().get_parent().unwrap();
-            let fun_name = ctx.gen_string(generator, current_fun.get_name().to_str().unwrap());
-            let name_ptr = ctx
-                .builder
-                .build_in_bounds_gep(exception, &[zero, int32.const_int(4, false)], "name_ptr")
-                .unwrap();
-            ctx.builder.build_store(name_ptr, fun_name).unwrap();
-        }
+        // Get and store filename
+        let filename = loc.file.0;
+        let filename = ctx.gen_string(generator, &String::from(filename)).value;
+        let filename = cslice_model.check_value(type_context, ctx.ctx, filename).unwrap();
+        pexn.gep(ctx, |f| f.filename).store(ctx, filename);
+
+        let row = i32_model.constant(type_context, ctx.ctx, loc.row as u64);
+        pexn.gep(ctx, |f| f.line).store(ctx, row);
+
+        let column = i32_model.constant(type_context, ctx.ctx, loc.column as u64);
+        pexn.gep(ctx, |f| f.column).store(ctx, column);
+
+        let current_fn = ctx.builder.get_insert_block().unwrap().get_parent().unwrap();
+        let fn_name = ctx.gen_string(generator, current_fn.get_name().to_str().unwrap());
+        pexn.gep(ctx, |f| f.function).store(ctx, fn_name);

        let raise = get_builtins(generator, ctx, "__nac3_raise");
-        let exception = *exception;
-        ctx.build_call_or_invoke(raise, &[exception], "raise");
+        ctx.build_call_or_invoke(raise, &[pexn.value.into()], "raise");
    } else {
        let resume = get_builtins(generator, ctx, "__nac3_resume");
        ctx.build_call_or_invoke(resume, &[], "resume");
    }
+
    ctx.builder.build_unreachable().unwrap();
 }

@ -1575,14 +1586,16 @@ pub fn gen_stmt<G: CodeGenerator>(
        }
        StmtKind::AnnAssign { target, value, .. } => {
            if let Some(value) = value {
+                let value_ty = value.custom.unwrap();
                let Some(value) = generator.gen_expr(ctx, value)? else { return Ok(()) };
-                generator.gen_assign(ctx, target, value)?;
+                generator.gen_assign(ctx, target, value, value_ty)?;
            }
        }
        StmtKind::Assign { targets, value, .. } => {
+            let value_ty = value.custom.unwrap();
            let Some(value) = generator.gen_expr(ctx, value)? else { return Ok(()) };
            for target in targets {
-                generator.gen_assign(ctx, target, value.clone())?;
+                generator.gen_assign(ctx, target, value.clone(), value_ty)?;
            }
        }
        StmtKind::Continue { .. } => {
@ -1596,6 +1609,7 @@ pub fn gen_stmt<G: CodeGenerator>(
        StmtKind::For { .. } => generator.gen_for(ctx, stmt)?,
        StmtKind::With { .. } => generator.gen_with(ctx, stmt)?,
        StmtKind::AugAssign { target, op, value, .. } => {
+            let value_ty = value.custom.unwrap();
            let value = gen_binop_expr(
                generator,
                ctx,
@ -1604,7 +1618,7 @@ pub fn gen_stmt<G: CodeGenerator>(
                value,
                stmt.location,
            )?;
-            generator.gen_assign(ctx, target, value.unwrap())?;
+            generator.gen_assign(ctx, target, value.unwrap(), value_ty)?;
        }
        StmtKind::Try { .. } => gen_try(generator, ctx, stmt)?,
        StmtKind::Raise { exc, .. } => {
@ -1614,30 +1628,43 @@ pub fn gen_stmt<G: CodeGenerator>(
                } else {
                    return Ok(());
                };
-                gen_raise(generator, ctx, Some(&exc), stmt.location);
+
+                let type_context = generator.type_context(ctx.ctx);
+                let pexn_model = PtrModel(StructModel(Exception));
+                let exn = pexn_model.check_value(type_context, ctx.ctx, exc).unwrap();
+
+                gen_raise(generator, ctx, Some(exn), stmt.location);
            } else {
                gen_raise(generator, ctx, None, stmt.location);
            }
        }
        StmtKind::Assert { test, msg, .. } => {
-            let test = if let Some(v) = generator.gen_expr(ctx, test)? {
-                v.to_basic_value_enum(ctx, generator, test.custom.unwrap())?
-            } else {
+            let type_context = generator.type_context(ctx.ctx);
+            let byte_model = IntModel(Byte);
+            let cslice_model = StructModel(CSlice);
+
+            let Some(test) = generator.gen_expr(ctx, test)? else {
                return Ok(());
            };
+            let test = test.to_basic_value_enum(ctx, generator, ctx.primitives.bool)?;
+            let test = byte_model.check_value(type_context, ctx.ctx, test).unwrap(); // Python `bool` is represented as `i8` in nac3core
+
+            // Check `msg`
            let err_msg = match msg {
                Some(msg) => {
-                    if let Some(v) = generator.gen_expr(ctx, msg)? {
-                        v.to_basic_value_enum(ctx, generator, msg.custom.unwrap())?
-                    } else {
+                    let Some(msg) = generator.gen_expr(ctx, msg)? else {
                        return Ok(());
-                    }
+                    };
+
+                    let msg = msg.to_basic_value_enum(ctx, generator, ctx.primitives.str)?;
+                    cslice_model.check_value(type_context, ctx.ctx, msg).unwrap()
                }
                None => ctx.gen_string(generator, ""),
            };
+
            ctx.make_assert_impl(
                generator,
-                test.into_int_value(),
+                test.value,
                "0:AssertionError",
                err_msg,
                [None, None, None],
--- a/nac3core/src/codegen/structure/cslice.rs
+++ b/nac3core/src/codegen/structure/cslice.rs
@ -0,0 +1,43 @@
+use crate::codegen::{model::*, CodeGenContext};
+
+/// Fields of [`CSlice<'ctx>`].
+pub struct CSliceFields<F: FieldVisitor> {
+    /// Pointer to the data.
+    pub base: F::Field<PtrModel<IntModel<Byte>>>,
+    /// Number of bytes of the data.
+    pub len: F::Field<IntModel<SizeT>>,
+}
+
+/// See <https://crates.io/crates/cslice>.
+///
+/// Additionally, see <https://github.com/m-labs/artiq/blob/b0d2705c385f64b6e6711c1726cd9178f40b598e/artiq/firmware/libeh/eh_artiq.rs>)
+/// for ARTIQ-specific notes.
+#[derive(Debug, Clone, Copy, Default)]
+pub struct CSlice;
+
+impl StructKind for CSlice {
+    type Fields<F: FieldVisitor> = CSliceFields<F>;
+
+    fn visit_fields<F: FieldVisitor>(&self, visitor: &mut F) -> Self::Fields<F> {
+        Self::Fields { base: visitor.add("base"), len: visitor.add("len") }
+    }
+}
+
+impl StructModel<CSlice> {
+    /// Create a [`CSlice`].
+    ///
+    /// `base` and `len` must be LLVM global constants.
+    pub fn create_const<'ctx>(
+        &self,
+        type_context: TypeContext<'ctx>,
+        ctx: &CodeGenContext<'ctx, '_>,
+        base: Ptr<'ctx, IntModel<Byte>>,
+        len: Int<'ctx, SizeT>,
+    ) -> Struct<'ctx, CSlice> {
+        let value = self
+            .0
+            .get_struct_type(type_context, ctx.ctx)
+            .const_named_struct(&[base.value.into(), len.value.into()]);
+        self.believe_value(value)
+    }
+}
--- a/nac3core/src/codegen/structure/exception.rs
+++ b/nac3core/src/codegen/structure/exception.rs
@ -0,0 +1,57 @@
+use crate::codegen::model::*;
+
+use super::cslice::CSlice;
+
+/// The LLVM int type of an Exception ID.
+pub type ExceptionId = Int32;
+
+/// Fields of [`Exception<'ctx>`]
+///
+/// The definition came from `pub struct Exception<'a>` in
+/// <https://github.com/m-labs/artiq/blob/master/artiq/firmware/libeh/eh_artiq.rs>.
+pub struct ExceptionFields<F: FieldVisitor> {
+    /// nac3core's ID of the exception
+    pub id: F::Field<IntModel<ExceptionId>>,
+    /// The name of the file this `Exception` was raised in.
+    pub filename: F::Field<StructModel<CSlice>>,
+    /// The line number in the file this `Exception` was raised in.
+    pub line: F::Field<IntModel<Int32>>,
+    /// The column number in the file this `Exception` was raised in.
+    pub column: F::Field<IntModel<Int32>>,
+    /// The name of the Python function this `Exception` was raised in.
+    pub function: F::Field<StructModel<CSlice>>,
+    /// The message of this Exception.
+    ///
+    /// The message can optionally contain integer parameters `{0}`, `{1}`, and `{2}` in its string,
+    /// where they will be substituted by `params[0]`, `params[1]`, and `params[2]` respectively (as `int64_t`s).
+    /// Here is an example:
+    ///
+    /// ```ignore
+    /// "Index {0} is out of bounds! List only has {1} element(s)."
+    /// ```
+    ///
+    /// In this case, `params[0]` and `params[1]` must be specified, and `params[2]` is ***unused***.
+    /// Having only 3 parameters is a constraint in ARTIQ.
+    pub msg: F::Field<StructModel<CSlice>>,
+    pub params: [F::Field<IntModel<Int64>>; 3],
+}
+
+/// nac3core & ARTIQ's Exception
+#[derive(Debug, Clone, Copy, Default)]
+pub struct Exception;
+
+impl StructKind for Exception {
+    type Fields<F: FieldVisitor> = ExceptionFields<F>;
+
+    fn visit_fields<F: FieldVisitor>(&self, visitor: &mut F) -> Self::Fields<F> {
+        Self::Fields {
+            id: visitor.add("id"),
+            filename: visitor.add("filename"),
+            line: visitor.add("line"),
+            column: visitor.add("column"),
+            function: visitor.add("function"),
+            msg: visitor.add("msg"),
+            params: [visitor.add("params[0]"), visitor.add("params[1]"), visitor.add("params[2]")],
+        }
+    }
+}
--- a/nac3core/src/codegen/structure/mod.rs
+++ b/nac3core/src/codegen/structure/mod.rs
@ -0,0 +1,3 @@
+pub mod cslice;
+pub mod exception;
+pub mod ndarray;
--- a/nac3core/src/codegen/structure/ndarray.rs
+++ b/nac3core/src/codegen/structure/ndarray.rs
@ -0,0 +1,27 @@
+use crate::codegen::*;
+
+pub struct NpArrayFields<F: FieldVisitor> {
+    pub data: F::Field<PtrModel<IntModel<Byte>>>,
+    pub itemsize: F::Field<IntModel<SizeT>>,
+    pub ndims: F::Field<IntModel<SizeT>>,
+    pub shape: F::Field<PtrModel<IntModel<SizeT>>>,
+    pub strides: F::Field<PtrModel<IntModel<SizeT>>>,
+}
+
+// TODO: Rename to `NDArray` when the old NDArray is removed.
+#[derive(Debug, Clone, Copy, Default)]
+pub struct NpArray;
+
+impl StructKind for NpArray {
+    type Fields<F: FieldVisitor> = NpArrayFields<F>;
+
+    fn visit_fields<F: FieldVisitor>(&self, visitor: &mut F) -> Self::Fields<F> {
+        Self::Fields {
+            data: visitor.add("data"),
+            itemsize: visitor.add("itemsize"),
+            ndims: visitor.add("ndims"),
+            shape: visitor.add("shape"),
+            strides: visitor.add("strides"),
+        }
+    }
+}
--- a/nac3core/src/codegen/test.rs
+++ b/nac3core/src/codegen/test.rs
@ -189,6 +189,8 @@ fn test_primitives() {
        let expected = indoc! {"
            ; ModuleID = 'test'
            source_filename = \"test\"
+            target datalayout = \"e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128\"
+            target triple = \"x86_64-unknown-linux-gnu\"

            ; Function Attrs: mustprogress nofree norecurse nosync nounwind readnone willreturn
            define i32 @testing(i32 %0, i32 %1) local_unnamed_addr #0 !dbg !4 {
@ -368,6 +370,8 @@ fn test_simple_call() {
        let expected = indoc! {"
            ; ModuleID = 'test'
            source_filename = \"test\"
+            target datalayout = \"e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128\"
+            target triple = \"x86_64-unknown-linux-gnu\"

            ; Function Attrs: mustprogress nofree norecurse nosync nounwind readnone willreturn
            define i32 @testing(i32 %0) local_unnamed_addr #0 !dbg !5 {
--- a/nac3core/src/codegen/util/array_writer.rs
+++ b/nac3core/src/codegen/util/array_writer.rs
@ -0,0 +1,34 @@
+use crate::codegen::{model::*, CodeGenContext, CodeGenerator};
+
+/// A closure containing details on how to write to/initialize an array.
+#[allow(clippy::type_complexity)]
+pub struct ArrayWriter<'ctx, G: CodeGenerator + ?Sized, Len: IntKind, Item: Model> {
+    /// Number of items to write
+    pub len: Int<'ctx, Len>,
+    /// Implementation to write to an array given its base pointer.
+    pub write: Box<
+        dyn Fn(
+                &mut G,
+                &mut CodeGenContext<'ctx, '_>,
+                Ptr<'ctx, Item>, // Base pointer
+            ) -> Result<(), String>
+            + 'ctx,
+    >,
+}
+
+impl<'ctx, G: CodeGenerator + ?Sized, Len: IntKind, Item: Model> ArrayWriter<'ctx, G, Len, Item> {
+    pub fn alloca_array_and_write(
+        &self,
+        generator: &mut G,
+        ctx: &mut CodeGenContext<'ctx, '_>,
+        name: &str,
+    ) -> Result<Ptr<'ctx, Item>, String> {
+        let tyctx = generator.type_context(ctx.ctx);
+
+        let item_model = Item::default();
+
+        let item_array = item_model.array_alloca(tyctx, ctx, self.len.value, name);
+        (self.write)(generator, ctx, item_array)?;
+        Ok(item_array)
+    }
+}
--- a/nac3core/src/codegen/util/control.rs
+++ b/nac3core/src/codegen/util/control.rs
@ -0,0 +1,42 @@
+use crate::codegen::{
+    model::*,
+    stmt::{gen_for_callback_incrementing, BreakContinueHooks},
+    CodeGenContext, CodeGenerator,
+};
+
+// TODO: Document
+// TODO: Rename function
+/// Only allows positive steps
+pub fn gen_model_for<'ctx, 'a, G, F, I>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, 'a>,
+    start: Int<'ctx, I>,
+    stop: Int<'ctx, I>,
+    step: Int<'ctx, I>,
+    body: F,
+) -> Result<(), String>
+where
+    G: CodeGenerator + ?Sized,
+    F: FnOnce(
+        &mut G,
+        &mut CodeGenContext<'ctx, 'a>,
+        BreakContinueHooks<'ctx>,
+        Int<'ctx, I>,
+    ) -> Result<(), String>,
+    I: IntKind,
+{
+    let int_model = IntModel(I::default());
+
+    gen_for_callback_incrementing(
+        generator,
+        ctx,
+        None,
+        start.value,
+        (stop.value, false),
+        |g, ctx, hooks, i| {
+            let i = int_model.believe_value(i);
+            body(g, ctx, hooks, i)
+        },
+        step.value,
+    )
+}
--- a/nac3core/src/codegen/util/mod.rs
+++ b/nac3core/src/codegen/util/mod.rs
@ -0,0 +1,3 @@
+pub mod array_writer;
+pub mod control;
+pub mod shape;
--- a/nac3core/src/codegen/util/shape.rs
+++ b/nac3core/src/codegen/util/shape.rs
@ -0,0 +1,127 @@
+use inkwell::values::BasicValueEnum;
+
+use crate::{
+    codegen::{
+        classes::{ListValue, UntypedArrayLikeAccessor},
+        model::*,
+        CodeGenContext, CodeGenerator,
+    },
+    typecheck::typedef::{Type, TypeEnum},
+};
+
+use super::{array_writer::ArrayWriter, control::gen_model_for};
+
+// TODO: Generalize to complex iterables under a common interface
+/// Create an [`ArrayWriter`] from a NumPy-like `shape` argument input.
+/// * `shape` - The `shape` parameter.
+/// * `shape_ty` - The element type of the `NDArray`.
+///
+/// The `shape` argument type may only be one of the following:
+///   1. A list of `int32`;   e.g., `np.empty([600, 800, 3])`
+///   2. A tuple of `int32`;  e.g., `np.empty((600, 800, 3))`
+///   3. A scalar `int32`;     e.g., `np.empty(3)`, this is functionally equivalent to `np.empty([3])`
+///
+/// The `int32` values will be sign-extended to `SizeT`
+pub fn make_shape_writer<'ctx, G>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, '_>,
+    shape: BasicValueEnum<'ctx>,
+    shape_ty: Type,
+) -> ArrayWriter<'ctx, G, SizeT, IntModel<SizeT>>
+where
+    G: CodeGenerator + ?Sized,
+{
+    let tyctx = generator.type_context(ctx.ctx);
+    let sizet_model = IntModel(SizeT);
+
+    match &*ctx.unifier.get_ty(shape_ty) {
+        TypeEnum::TObj { obj_id, .. }
+            if *obj_id == ctx.primitives.list.obj_id(&ctx.unifier).unwrap() =>
+        {
+            // 1. A list of `int32`;   e.g., `np.empty([600, 800, 3])`
+
+            // TODO: Remove ListValue with Model
+
+            let shape = ListValue::from_ptr_val(shape.into_pointer_value(), tyctx.size_type, None);
+            let len =
+                sizet_model.check_value(tyctx, ctx.ctx, shape.load_size(ctx, Some("len"))).unwrap();
+
+            ArrayWriter {
+                len,
+                write: Box::new(move |generator, ctx, dst_array| {
+                    gen_model_for(
+                        generator,
+                        ctx,
+                        sizet_model.constant(tyctx, ctx.ctx, 0),
+                        len,
+                        sizet_model.constant(tyctx, ctx.ctx, 1),
+                        |generator, ctx, _hooks, i| {
+                            let dim =
+                                shape.data().get(ctx, generator, &i.value, None).into_int_value();
+                            let dim = sizet_model.s_extend_or_bit_cast(tyctx, ctx, dim, "");
+
+                            dst_array.offset(tyctx, ctx, i.value, "pdim").store(ctx, dim);
+                            Ok(())
+                        },
+                    )
+                }),
+            }
+        }
+        TypeEnum::TTuple { ty: tuple_types } => {
+            // 2. A tuple of ints; e.g., `np.empty((600, 800, 3))`
+
+            let ndims = tuple_types.len();
+
+            // A tuple has to be a StructValue
+            // Read [`codegen::expr::gen_expr`] to see how `nac3core` translates a Python tuple into LLVM.
+            let shape = shape.into_struct_value();
+
+            ArrayWriter {
+                len: sizet_model.constant(tyctx, ctx.ctx, ndims as u64),
+                write: Box::new(move |_generator, ctx, dst_array| {
+                    for axis in 0..ndims {
+                        let dim = ctx
+                            .builder
+                            .build_extract_value(shape, axis as u32, format!("dim{axis}").as_str())
+                            .unwrap()
+                            .into_int_value();
+                        let dim = sizet_model.s_extend_or_bit_cast(tyctx, ctx, dim, "");
+
+                        dst_array
+                            .offset(
+                                tyctx,
+                                ctx,
+                                sizet_model.constant(tyctx, ctx.ctx, axis as u64).value,
+                                "pdim",
+                            )
+                            .store(ctx, dim);
+                    }
+                    Ok(())
+                }),
+            }
+        }
+        TypeEnum::TObj { obj_id, .. }
+            if *obj_id == ctx.primitives.int32.obj_id(&ctx.unifier).unwrap() =>
+        {
+            // 3. A scalar int; e.g., `np.empty(3)`, this is functionally equivalent to `np.empty([3])`
+
+            // The value has to be an integer
+            let shape_int = shape.into_int_value();
+
+            ArrayWriter {
+                len: sizet_model.constant(tyctx, ctx.ctx, 1),
+                write: Box::new(move |_generator, ctx, dst_array| {
+                    let dim = sizet_model.s_extend_or_bit_cast(tyctx, ctx, shape_int, "");
+
+                    // Set shape[0] = shape_int
+                    dst_array
+                        .offset(tyctx, ctx, sizet_model.constant(tyctx, ctx.ctx, 0).value, "pdim")
+                        .store(ctx, dim);
+
+                    Ok(())
+                }),
+            }
+        }
+        _ => panic!("encountered shape type"),
+    }
+}
--- a/nac3core/src/lib.rs
+++ b/nac3core/src/lib.rs
@ -23,4 +23,3 @@ pub mod codegen;
 pub mod symbol_resolver;
 pub mod toplevel;
 pub mod typecheck;
-pub mod util;
--- a/nac3core/src/toplevel/builtins.rs
+++ b/nac3core/src/toplevel/builtins.rs
@ -1,6 +1,5 @@
 use std::iter::once;

-use crate::util::SizeVariant;
 use helper::{debug_assert_prim_is_allowed, make_exception_fields, PrimDefDetails};
 use indexmap::IndexMap;
 use inkwell::{
@ -10,16 +9,20 @@ use inkwell::{
    IntPredicate,
 };
 use itertools::Either;
+use ndarray::basic::call_nac3_ndarray_len;
 use strum::IntoEnumIterator;

 use crate::{
    codegen::{
        builtin_fns,
-        classes::{ArrayLikeValue, NDArrayValue, ProxyValue, RangeValue, TypedArrayLikeAccessor},
+        classes::{ProxyValue, RangeValue},
        expr::destructure_range,
        irrt::*,
+        model::*,
        numpy::*,
+        numpy_new,
        stmt::exn_constructor,
+        structure::ndarray::NpArray,
    },
    symbol_resolver::SymbolValue,
    toplevel::{helper::PrimDef, numpy::make_ndarray_ty},
@ -279,10 +282,19 @@ pub fn get_builtins(unifier: &mut Unifier, primitives: &PrimitiveStore) -> Built
        .collect()
 }

-fn size_variant_to_int_type(variant: SizeVariant, primitives: &PrimitiveStore) -> Type {
-    match variant {
-        SizeVariant::Bits32 => primitives.int32,
-        SizeVariant::Bits64 => primitives.int64,
+/// A helper enum used by [`BuiltinBuilder`]
+#[derive(Clone, Copy)]
+enum SizeVariant {
+    Bits32,
+    Bits64,
+}
+
+impl SizeVariant {
+    fn of_int(self, primitives: &PrimitiveStore) -> Type {
+        match self {
+            SizeVariant::Bits32 => primitives.int32,
+            SizeVariant::Bits64 => primitives.int64,
+        }
    }
 }

@ -338,8 +350,8 @@ impl<'a> BuiltinBuilder<'a> {
        let (is_some_ty, unwrap_ty, option_tvar) =
            if let TypeEnum::TObj { fields, params, .. } = unifier.get_ty(option).as_ref() {
                (
-                    *fields.get(&PrimDef::OptionIsSome.simple_name().into()).unwrap(),
-                    *fields.get(&PrimDef::OptionUnwrap.simple_name().into()).unwrap(),
+                    *fields.get(&PrimDef::FunOptionIsSome.simple_name().into()).unwrap(),
+                    *fields.get(&PrimDef::FunOptionUnwrap.simple_name().into()).unwrap(),
                    iter_type_vars(params).next().unwrap(),
                )
            } else {
@ -354,9 +366,9 @@ impl<'a> BuiltinBuilder<'a> {
        let ndarray_dtype_tvar = iter_type_vars(ndarray_params).next().unwrap();
        let ndarray_ndims_tvar = iter_type_vars(ndarray_params).nth(1).unwrap();
        let ndarray_copy_ty =
-            *ndarray_fields.get(&PrimDef::NDArrayCopy.simple_name().into()).unwrap();
+            *ndarray_fields.get(&PrimDef::FunNDArrayCopy.simple_name().into()).unwrap();
        let ndarray_fill_ty =
-            *ndarray_fields.get(&PrimDef::NDArrayFill.simple_name().into()).unwrap();
+            *ndarray_fields.get(&PrimDef::FunNDArrayFill.simple_name().into()).unwrap();

        let num_ty = unifier.get_fresh_var_with_range(
            &[int32, int64, float, boolean, uint32, uint64],
@ -456,14 +468,14 @@ impl<'a> BuiltinBuilder<'a> {
            PrimDef::Exception => self.build_exception_class_related(prim),

            PrimDef::Option
-            | PrimDef::OptionIsSome
-            | PrimDef::OptionIsNone
-            | PrimDef::OptionUnwrap
+            | PrimDef::FunOptionIsSome
+            | PrimDef::FunOptionIsNone
+            | PrimDef::FunOptionUnwrap
            | PrimDef::FunSome => self.build_option_class_related(prim),

            PrimDef::List => self.build_list_class_related(prim),

-            PrimDef::NDArray | PrimDef::NDArrayCopy | PrimDef::NDArrayFill => {
+            PrimDef::NDArray | PrimDef::FunNDArrayCopy | PrimDef::FunNDArrayFill => {
                self.build_ndarray_class_related(prim)
            }

@ -484,6 +496,8 @@ impl<'a> BuiltinBuilder<'a> {
            | PrimDef::FunNpEye
            | PrimDef::FunNpIdentity => self.build_ndarray_other_factory_function(prim),

+            PrimDef::FunNpReshape => self.build_ndarray_view_functions(prim),
+
            PrimDef::FunStr => self.build_str_function(),

            PrimDef::FunFloor | PrimDef::FunFloor64 | PrimDef::FunCeil | PrimDef::FunCeil64 => {
@ -502,7 +516,9 @@ impl<'a> BuiltinBuilder<'a> {

            PrimDef::FunMin | PrimDef::FunMax => self.build_min_max_function(prim),

-            PrimDef::FunNpMin | PrimDef::FunNpMax => self.build_np_min_max_function(prim),
+            PrimDef::FunNpArgmin | PrimDef::FunNpArgmax | PrimDef::FunNpMin | PrimDef::FunNpMax => {
+                self.build_np_max_min_function(prim)
+            }

            PrimDef::FunNpMinimum | PrimDef::FunNpMaximum => {
                self.build_np_minimum_maximum_function(prim)
@ -554,7 +570,7 @@ impl<'a> BuiltinBuilder<'a> {
            match (&tld, prim.details()) {
                (
                    TopLevelDef::Class { name, object_id, .. },
-                    PrimDefDetails::PrimClass { name: exp_name },
+                    PrimDefDetails::PrimClass { name: exp_name, .. },
                ) => {
                    let exp_object_id = prim.id();
                    assert_eq!(name, &exp_name.into());
@ -784,9 +800,9 @@ impl<'a> BuiltinBuilder<'a> {
            prim,
            &[
                PrimDef::Option,
-                PrimDef::OptionIsSome,
-                PrimDef::OptionIsNone,
-                PrimDef::OptionUnwrap,
+                PrimDef::FunOptionIsSome,
+                PrimDef::FunOptionIsNone,
+                PrimDef::FunOptionUnwrap,
                PrimDef::FunSome,
            ],
        );
@ -799,9 +815,9 @@ impl<'a> BuiltinBuilder<'a> {
                fields: Vec::default(),
                attributes: Vec::default(),
                methods: vec![
-                    Self::create_method(PrimDef::OptionIsSome, self.is_some_ty.0),
-                    Self::create_method(PrimDef::OptionIsNone, self.is_some_ty.0),
-                    Self::create_method(PrimDef::OptionUnwrap, self.unwrap_ty.0),
+                    Self::create_method(PrimDef::FunOptionIsSome, self.is_some_ty.0),
+                    Self::create_method(PrimDef::FunOptionIsNone, self.is_some_ty.0),
+                    Self::create_method(PrimDef::FunOptionUnwrap, self.unwrap_ty.0),
                ],
                ancestors: vec![TypeAnnotation::CustomClass {
                    id: prim.id(),
@ -812,7 +828,7 @@ impl<'a> BuiltinBuilder<'a> {
                loc: None,
            },

-            PrimDef::OptionUnwrap => TopLevelDef::Function {
+            PrimDef::FunOptionUnwrap => TopLevelDef::Function {
                name: prim.name().into(),
                simple_name: prim.simple_name().into(),
                signature: self.unwrap_ty.0,
@ -826,7 +842,7 @@ impl<'a> BuiltinBuilder<'a> {
                loc: None,
            },

-            PrimDef::OptionIsNone | PrimDef::OptionIsSome => TopLevelDef::Function {
+            PrimDef::FunOptionIsNone | PrimDef::FunOptionIsSome => TopLevelDef::Function {
                name: prim.name().to_string(),
                simple_name: prim.simple_name().into(),
                signature: self.is_some_ty.0,
@ -847,10 +863,10 @@ impl<'a> BuiltinBuilder<'a> {
                        };

                        let returned_int = match prim {
-                            PrimDef::OptionIsNone => {
+                            PrimDef::FunOptionIsNone => {
                                ctx.builder.build_is_null(ptr, prim.simple_name())
                            }
-                            PrimDef::OptionIsSome => {
+                            PrimDef::FunOptionIsSome => {
                                ctx.builder.build_is_not_null(ptr, prim.simple_name())
                            }
                            _ => unreachable!(),
@ -923,7 +939,7 @@ impl<'a> BuiltinBuilder<'a> {
    fn build_ndarray_class_related(&self, prim: PrimDef) -> TopLevelDef {
        debug_assert_prim_is_allowed(
            prim,
-            &[PrimDef::NDArray, PrimDef::NDArrayCopy, PrimDef::NDArrayFill],
+            &[PrimDef::NDArray, PrimDef::FunNDArrayCopy, PrimDef::FunNDArrayFill],
        );

        match prim {
@ -934,8 +950,8 @@ impl<'a> BuiltinBuilder<'a> {
                fields: Vec::default(),
                attributes: Vec::default(),
                methods: vec![
-                    Self::create_method(PrimDef::NDArrayCopy, self.ndarray_copy_ty.0),
-                    Self::create_method(PrimDef::NDArrayFill, self.ndarray_fill_ty.0),
+                    Self::create_method(PrimDef::FunNDArrayCopy, self.ndarray_copy_ty.0),
+                    Self::create_method(PrimDef::FunNDArrayFill, self.ndarray_fill_ty.0),
                ],
                ancestors: Vec::default(),
                constructor: None,
@ -943,7 +959,7 @@ impl<'a> BuiltinBuilder<'a> {
                loc: None,
            },

-            PrimDef::NDArrayCopy => TopLevelDef::Function {
+            PrimDef::FunNDArrayCopy => TopLevelDef::Function {
                name: prim.name().into(),
                simple_name: prim.simple_name().into(),
                signature: self.ndarray_copy_ty.0,
@ -953,15 +969,14 @@ impl<'a> BuiltinBuilder<'a> {
                resolver: None,
                codegen_callback: Some(Arc::new(GenCall::new(Box::new(
                    |ctx, obj, fun, args, generator| {
-                        todo!()
-                        // gen_ndarray_copy(ctx, &obj, fun, &args, generator)
-                        //     .map(|val| Some(val.as_basic_value_enum()))
+                        gen_ndarray_copy(ctx, &obj, fun, &args, generator)
+                            .map(|val| Some(val.as_basic_value_enum()))
                    },
                )))),
                loc: None,
            },

-            PrimDef::NDArrayFill => TopLevelDef::Function {
+            PrimDef::FunNDArrayFill => TopLevelDef::Function {
                name: prim.name().into(),
                simple_name: prim.simple_name().into(),
                signature: self.ndarray_fill_ty.0,
@ -971,9 +986,8 @@ impl<'a> BuiltinBuilder<'a> {
                resolver: None,
                codegen_callback: Some(Arc::new(GenCall::new(Box::new(
                    |ctx, obj, fun, args, generator| {
-                        todo!()
-                        // gen_ndarray_fill(ctx, &obj, fun, &args, generator)?;
-                        // Ok(None)
+                        gen_ndarray_fill(ctx, &obj, fun, &args, generator)?;
+                        Ok(None)
                    },
                )))),
                loc: None,
@ -1053,7 +1067,7 @@ impl<'a> BuiltinBuilder<'a> {
        );

        // The size variant of the function determines the size of the returned int.
-        let int_sized = size_variant_to_int_type(size_variant, self.primitives);
+        let int_sized = size_variant.of_int(self.primitives);

        let ndarray_int_sized =
            make_ndarray_ty(self.unifier, self.primitives, Some(int_sized), Some(common_ndim.ty));
@ -1078,7 +1092,7 @@ impl<'a> BuiltinBuilder<'a> {
                let arg_ty = fun.0.args[0].ty;
                let arg = args[0].1.clone().to_basic_value_enum(ctx, generator, arg_ty)?;

-                let ret_elem_ty = size_variant_to_int_type(size_variant, &ctx.primitives);
+                let ret_elem_ty = size_variant.of_int(&ctx.primitives);
                Ok(Some(builtin_fns::call_round(generator, ctx, (arg_ty, arg), ret_elem_ty)?))
            }),
        )
@ -1119,7 +1133,7 @@ impl<'a> BuiltinBuilder<'a> {
            make_ndarray_ty(self.unifier, self.primitives, Some(float), Some(common_ndim.ty));

        // The size variant of the function determines the type of int returned
-        let int_sized = size_variant_to_int_type(size_variant, self.primitives);
+        let int_sized = size_variant.of_int(self.primitives);
        let ndarray_int_sized =
            make_ndarray_ty(self.unifier, self.primitives, Some(int_sized), Some(common_ndim.ty));

@ -1142,7 +1156,7 @@ impl<'a> BuiltinBuilder<'a> {
                let arg_ty = fun.0.args[0].ty;
                let arg = args[0].1.clone().to_basic_value_enum(ctx, generator, arg_ty)?;

-                let ret_elem_ty = size_variant_to_int_type(size_variant, &ctx.primitives);
+                let ret_elem_ty = size_variant.of_int(&ctx.primitives);
                let func = match kind {
                    Kind::Ceil => builtin_fns::call_ceil,
                    Kind::Floor => builtin_fns::call_floor,
@ -1193,14 +1207,15 @@ impl<'a> BuiltinBuilder<'a> {
            self.ndarray_float,
            &[(self.ndarray_factory_fn_shape_arg_tvar.ty, "shape")],
            Box::new(move |ctx, obj, fun, args, generator| {
-                todo!()
-                // let func = match prim {
-                //     PrimDef::FunNpNDArray | PrimDef::FunNpEmpty => gen_ndarray_empty,
-                //     PrimDef::FunNpZeros => gen_ndarray_zeros,
-                //     PrimDef::FunNpOnes => gen_ndarray_ones,
-                //     _ => unreachable!(),
-                // };
-                // func(ctx, &obj, fun, &args, generator).map(|val| Some(val.as_basic_value_enum()))
+                let func = match prim {
+                    PrimDef::FunNpNDArray | PrimDef::FunNpEmpty => {
+                        numpy_new::factory::gen_ndarray_empty
+                    }
+                    PrimDef::FunNpZeros => numpy_new::factory::gen_ndarray_zeros,
+                    PrimDef::FunNpOnes => numpy_new::factory::gen_ndarray_ones,
+                    _ => unreachable!(),
+                };
+                func(ctx, &obj, fun, &args, generator).map(|val| Some(val.as_basic_value_enum()))
            }),
        )
    }
@ -1246,9 +1261,8 @@ impl<'a> BuiltinBuilder<'a> {
                    resolver: None,
                    codegen_callback: Some(Arc::new(GenCall::new(Box::new(
                        |ctx, obj, fun, args, generator| {
-                            todo!()
-                            // gen_ndarray_array(ctx, &obj, fun, &args, generator)
-                            //     .map(|val| Some(val.as_basic_value_enum()))
+                            gen_ndarray_array(ctx, &obj, fun, &args, generator)
+                                .map(|val| Some(val.as_basic_value_enum()))
                        },
                    )))),
                    loc: None,
@ -1266,9 +1280,8 @@ impl<'a> BuiltinBuilder<'a> {
                    // type variable
                    &[(self.list_int32, "shape"), (tv.ty, "fill_value")],
                    Box::new(move |ctx, obj, fun, args, generator| {
-                        todo!()
-                        // gen_ndarray_full(ctx, &obj, fun, &args, generator)
-                        //     .map(|val| Some(val.as_basic_value_enum()))
+                        numpy_new::factory::gen_ndarray_full(ctx, &obj, fun, &args, generator)
+                            .map(|val| Some(val.as_basic_value_enum()))
                    }),
                )
            }
@ -1300,9 +1313,8 @@ impl<'a> BuiltinBuilder<'a> {
                    resolver: None,
                    codegen_callback: Some(Arc::new(GenCall::new(Box::new(
                        |ctx, obj, fun, args, generator| {
-                            todo!()
-                            // gen_ndarray_eye(ctx, &obj, fun, &args, generator)
-                            //     .map(|val| Some(val.as_basic_value_enum()))
+                            gen_ndarray_eye(ctx, &obj, fun, &args, generator)
+                                .map(|val| Some(val.as_basic_value_enum()))
                        },
                    )))),
                    loc: None,
@ -1315,15 +1327,49 @@ impl<'a> BuiltinBuilder<'a> {
                self.ndarray_float_2d,
                &[(int32, "n")],
                Box::new(|ctx, obj, fun, args, generator| {
-                    todo!()
-                    // gen_ndarray_identity(ctx, &obj, fun, &args, generator)
-                    //     .map(|val| Some(val.as_basic_value_enum()))
+                    gen_ndarray_identity(ctx, &obj, fun, &args, generator)
+                        .map(|val| Some(val.as_basic_value_enum()))
                }),
            ),
            _ => unreachable!(),
        }
    }

+    // Build functions related to NDArray views
+    fn build_ndarray_view_functions(&mut self, prim: PrimDef) -> TopLevelDef {
+        debug_assert_prim_is_allowed(prim, &[PrimDef::FunNpReshape]);
+
+        match prim {
+            PrimDef::FunNpReshape => {
+                // TODO: Support scalar inputs, e.g., `np.reshape(99, (1, 1, 1, 1))`
+
+                let new_ndim_ty = self.unifier.get_fresh_var(Some("NewNDim".into()), None);
+                let returned_ndarray_ty = make_ndarray_ty(
+                    self.unifier,
+                    self.primitives,
+                    Some(self.ndarray_dtype_tvar.ty),
+                    Some(new_ndim_ty.ty),
+                );
+
+                create_fn_by_codegen(
+                    self.unifier,
+                    &into_var_map([self.ndarray_dtype_tvar, self.ndarray_ndims_tvar, new_ndim_ty]),
+                    prim.name(),
+                    returned_ndarray_ty,
+                    &[
+                        (self.primitives.ndarray, "array"),
+                        (self.ndarray_factory_fn_shape_arg_tvar.ty, "shape"),
+                    ],
+                    Box::new(|ctx, obj, fun, args, generator| {
+                        numpy_new::view::gen_ndarray_reshape(ctx, &obj, fun, &args, generator)
+                            .map(|val| Some(val.as_basic_value_enum()))
+                    }),
+                )
+            }
+            _ => unreachable!(),
+        }
+    }
+
    /// Build the `str()` function.
    fn build_str_function(&mut self) -> TopLevelDef {
        let prim = PrimDef::FunStr;
@ -1461,51 +1507,13 @@ impl<'a> BuiltinBuilder<'a> {
                                }
                            }
                            TypeEnum::TObj { obj_id, .. } if *obj_id == PrimDef::NDArray.id() => {
-                                let llvm_i32 = ctx.ctx.i32_type();
-                                let llvm_usize = generator.get_size_type(ctx.ctx);
+                                let tyctx = generator.type_context(ctx.ctx);
+                                let pndarray_model = PtrModel(StructModel(NpArray));

-                                let arg = NDArrayValue::from_ptr_val(
-                                    arg.into_pointer_value(),
-                                    llvm_usize,
-                                    None,
-                                );
-
-                                let ndims = arg.dim_sizes().size(ctx, generator);
-                                ctx.make_assert(
-                                    generator,
-                                    ctx.builder
-                                        .build_int_compare(
-                                            IntPredicate::NE,
-                                            ndims,
-                                            llvm_usize.const_zero(),
-                                            "",
-                                        )
-                                        .unwrap(),
-                                    "0:TypeError",
-                                    &format!("{name}() of unsized object", name = prim.name()),
-                                    [None, None, None],
-                                    ctx.current_loc,
-                                );
-
-                                let len = unsafe {
-                                    arg.dim_sizes().get_typed_unchecked(
-                                        ctx,
-                                        generator,
-                                        &llvm_usize.const_zero(),
-                                        None,
-                                    )
-                                };
-
-                                if len.get_type().get_bit_width() == 32 {
-                                    Some(len.into())
-                                } else {
-                                    Some(
-                                        ctx.builder
-                                            .build_int_truncate(len, llvm_i32, "len")
-                                            .map(Into::into)
-                                            .unwrap(),
-                                    )
-                                }
+                                let ndarray =
+                                    pndarray_model.check_value(tyctx, ctx.ctx, arg).unwrap();
+                                let len = call_nac3_ndarray_len(generator, ctx, ndarray);
+                                Some(len.value.as_basic_value_enum())
                            }
                            _ => unreachable!(),
                        }
@ -1554,39 +1562,45 @@ impl<'a> BuiltinBuilder<'a> {
        }
    }

-    /// Build the functions `np_min()` and `np_max()`.
-    fn build_np_min_max_function(&mut self, prim: PrimDef) -> TopLevelDef {
-        debug_assert_prim_is_allowed(prim, &[PrimDef::FunNpMin, PrimDef::FunNpMax]);
+    /// Build the functions `np_max()`, `np_min()`, `np_argmax()` and `np_argmin()`
+    /// Calls `call_numpy_max_min` with the function name
+    fn build_np_max_min_function(&mut self, prim: PrimDef) -> TopLevelDef {
+        debug_assert_prim_is_allowed(
+            prim,
+            &[PrimDef::FunNpArgmin, PrimDef::FunNpArgmax, PrimDef::FunNpMin, PrimDef::FunNpMax],
+        );

-        let ret_ty = self.unifier.get_fresh_var(Some("R".into()), None);
-        let var_map = self
-            .num_or_ndarray_var_map
-            .clone()
-            .into_iter()
-            .chain(once((ret_ty.id, ret_ty.ty)))
-            .collect::<IndexMap<_, _>>();
+        let (var_map, ret_ty) = match prim {
+            PrimDef::FunNpArgmax | PrimDef::FunNpArgmin => {
+                (self.num_or_ndarray_var_map.clone(), self.primitives.int64)
+            }
+            PrimDef::FunNpMax | PrimDef::FunNpMin => {
+                let ret_ty = self.unifier.get_fresh_var(Some("R".into()), None);
+                let var_map = self
+                    .num_or_ndarray_var_map
+                    .clone()
+                    .into_iter()
+                    .chain(once((ret_ty.id, ret_ty.ty)))
+                    .collect::<IndexMap<_, _>>();
+                (var_map, ret_ty.ty)
+            }
+            _ => unreachable!(),
+        };

        create_fn_by_codegen(
            self.unifier,
            &var_map,
            prim.name(),
-            ret_ty.ty,
-            &[(self.float_or_ndarray_ty.ty, "a")],
+            ret_ty,
+            &[(self.num_or_ndarray_ty.ty, "a")],
            Box::new(move |ctx, _, fun, args, generator| {
                let a_ty = fun.0.args[0].ty;
                let a = args[0].1.clone().to_basic_value_enum(ctx, generator, a_ty)?;

-                let func = match prim {
-                    PrimDef::FunNpMin => builtin_fns::call_numpy_min,
-                    PrimDef::FunNpMax => builtin_fns::call_numpy_max,
-                    _ => unreachable!(),
-                };
-
-                Ok(Some(func(generator, ctx, (a_ty, a))?))
+                Ok(Some(builtin_fns::call_numpy_max_min(generator, ctx, (a_ty, a), prim.name())?))
            }),
        )
    }
-
    /// Build the functions `np_minimum()` and `np_maximum()`.
    fn build_np_minimum_maximum_function(&mut self, prim: PrimDef) -> TopLevelDef {
        debug_assert_prim_is_allowed(prim, &[PrimDef::FunNpMinimum, PrimDef::FunNpMaximum]);
--- a/nac3core/src/toplevel/composer.rs
+++ b/nac3core/src/toplevel/composer.rs
@ -766,6 +766,7 @@ impl TopLevelComposer {
            let target_ty = get_type_from_type_annotation_kinds(
                &temp_def_list,
                unifier,
+                primitives,
                &def,
                &mut subst_list,
            )?;
@ -936,6 +937,7 @@ impl TopLevelComposer {
                        let ty = get_type_from_type_annotation_kinds(
                            temp_def_list.as_ref(),
                            unifier,
+                            primitives_store,
                            &type_annotation,
                            &mut None,
                        )?;
@ -1002,6 +1004,7 @@ impl TopLevelComposer {
                    get_type_from_type_annotation_kinds(
                        &temp_def_list,
                        unifier,
+                        primitives_store,
                        &return_ty_annotation,
                        &mut None,
                    )?
@ -1622,6 +1625,7 @@ impl TopLevelComposer {
                let self_type = get_type_from_type_annotation_kinds(
                    &def_list,
                    unifier,
+                    primitives_ty,
                    &make_self_type_annotation(type_vars, *object_id),
                    &mut None,
                )?;
@ -1803,7 +1807,11 @@ impl TopLevelComposer {

                        let ty_ann = make_self_type_annotation(type_vars, *class_id);
                        let self_ty = get_type_from_type_annotation_kinds(
-                            &def_list, unifier, &ty_ann, &mut None,
+                            &def_list,
+                            unifier,
+                            primitives_ty,
+                            &ty_ann,
+                            &mut None,
                        )?;
                        vars.extend(type_vars.iter().map(|ty| {
                            let TypeEnum::TVar { id, .. } = &*unifier.get_ty(*ty) else {
--- a/nac3core/src/toplevel/helper.rs
+++ b/nac3core/src/toplevel/helper.rs
@ -27,17 +27,22 @@ pub enum PrimDef {
    List,
    NDArray,

-    // Member Functions
-    OptionIsSome,
-    OptionIsNone,
-    OptionUnwrap,
-    NDArrayCopy,
-    NDArrayFill,
-    FunInt32,
-    FunInt64,
-    FunUInt32,
-    FunUInt64,
-    FunFloat,
+    // Option methods
+    FunOptionIsSome,
+    FunOptionIsNone,
+    FunOptionUnwrap,
+
+    // Option-related functions
+    FunSome,
+
+    // NDArray methods
+    FunNDArrayCopy,
+    FunNDArrayFill,
+
+    // Range methods
+    FunRangeInit,
+
+    // NumPy factory functions
    FunNpNDArray,
    FunNpEmpty,
    FunNpZeros,
@ -46,26 +51,20 @@ pub enum PrimDef {
    FunNpArray,
    FunNpEye,
    FunNpIdentity,
-    FunRound,
-    FunRound64,
+
+    // NumPy view functions
+    FunNpReshape,
+
+    // Miscellaneous NumPy & SciPy functions
    FunNpRound,
-    FunRangeInit,
-    FunStr,
-    FunBool,
-    FunFloor,
-    FunFloor64,
    FunNpFloor,
-    FunCeil,
-    FunCeil64,
    FunNpCeil,
-    FunLen,
-    FunMin,
    FunNpMin,
    FunNpMinimum,
-    FunMax,
+    FunNpArgmin,
    FunNpMax,
    FunNpMaximum,
-    FunAbs,
+    FunNpArgmax,
    FunNpIsNan,
    FunNpIsInf,
    FunNpSin,
@ -104,14 +103,30 @@ pub enum PrimDef {
    FunNpHypot,
    FunNpNextAfter,

-    // Top-Level Functions
-    FunSome,
+    // Miscellaneous Python & NAC3 functions
+    FunInt32,
+    FunInt64,
+    FunUInt32,
+    FunUInt64,
+    FunFloat,
+    FunRound,
+    FunRound64,
+    FunStr,
+    FunBool,
+    FunFloor,
+    FunFloor64,
+    FunCeil,
+    FunCeil64,
+    FunLen,
+    FunMin,
+    FunMax,
+    FunAbs,
 }

 /// Associated details of a [`PrimDef`]
 pub enum PrimDefDetails {
    PrimFunction { name: &'static str, simple_name: &'static str },
-    PrimClass { name: &'static str },
+    PrimClass { name: &'static str, get_ty_fn: fn(&PrimitiveStore) -> Type },
 }

 impl PrimDef {
@ -153,15 +168,17 @@ impl PrimDef {
    #[must_use]
    pub fn name(&self) -> &'static str {
        match self.details() {
-            PrimDefDetails::PrimFunction { name, .. } | PrimDefDetails::PrimClass { name } => name,
+            PrimDefDetails::PrimFunction { name, .. } | PrimDefDetails::PrimClass { name, .. } => {
+                name
+            }
        }
    }

    /// Get the associated details of this [`PrimDef`]
    #[must_use]
    pub fn details(self) -> PrimDefDetails {
-        fn class(name: &'static str) -> PrimDefDetails {
-            PrimDefDetails::PrimClass { name }
+        fn class(name: &'static str, get_ty_fn: fn(&PrimitiveStore) -> Type) -> PrimDefDetails {
+            PrimDefDetails::PrimClass { name, get_ty_fn }
        }

        fn fun(name: &'static str, simple_name: Option<&'static str>) -> PrimDefDetails {
@ -169,29 +186,37 @@ impl PrimDef {
        }

        match self {
-            PrimDef::Int32 => class("int32"),
-            PrimDef::Int64 => class("int64"),
-            PrimDef::Float => class("float"),
-            PrimDef::Bool => class("bool"),
-            PrimDef::None => class("none"),
-            PrimDef::Range => class("range"),
-            PrimDef::Str => class("str"),
-            PrimDef::Exception => class("Exception"),
-            PrimDef::UInt32 => class("uint32"),
-            PrimDef::UInt64 => class("uint64"),
-            PrimDef::Option => class("Option"),
-            PrimDef::OptionIsSome => fun("Option.is_some", Some("is_some")),
-            PrimDef::OptionIsNone => fun("Option.is_none", Some("is_none")),
-            PrimDef::OptionUnwrap => fun("Option.unwrap", Some("unwrap")),
-            PrimDef::List => class("list"),
-            PrimDef::NDArray => class("ndarray"),
-            PrimDef::NDArrayCopy => fun("ndarray.copy", Some("copy")),
-            PrimDef::NDArrayFill => fun("ndarray.fill", Some("fill")),
-            PrimDef::FunInt32 => fun("int32", None),
-            PrimDef::FunInt64 => fun("int64", None),
-            PrimDef::FunUInt32 => fun("uint32", None),
-            PrimDef::FunUInt64 => fun("uint64", None),
-            PrimDef::FunFloat => fun("float", None),
+            // Classes
+            PrimDef::Int32 => class("int32", |primitives| primitives.int32),
+            PrimDef::Int64 => class("int64", |primitives| primitives.int64),
+            PrimDef::Float => class("float", |primitives| primitives.float),
+            PrimDef::Bool => class("bool", |primitives| primitives.bool),
+            PrimDef::None => class("none", |primitives| primitives.none),
+            PrimDef::Range => class("range", |primitives| primitives.range),
+            PrimDef::Str => class("str", |primitives| primitives.str),
+            PrimDef::Exception => class("Exception", |primitives| primitives.exception),
+            PrimDef::UInt32 => class("uint32", |primitives| primitives.uint32),
+            PrimDef::UInt64 => class("uint64", |primitives| primitives.uint64),
+            PrimDef::Option => class("Option", |primitives| primitives.option),
+            PrimDef::List => class("list", |primitives| primitives.list),
+            PrimDef::NDArray => class("ndarray", |primitives| primitives.ndarray),
+
+            // Option methods
+            PrimDef::FunOptionIsSome => fun("Option.is_some", Some("is_some")),
+            PrimDef::FunOptionIsNone => fun("Option.is_none", Some("is_none")),
+            PrimDef::FunOptionUnwrap => fun("Option.unwrap", Some("unwrap")),
+
+            // Option-related functions
+            PrimDef::FunSome => fun("Some", None),
+
+            // NDArray methods
+            PrimDef::FunNDArrayCopy => fun("ndarray.copy", Some("copy")),
+            PrimDef::FunNDArrayFill => fun("ndarray.fill", Some("fill")),
+
+            // Range methods
+            PrimDef::FunRangeInit => fun("range.__init__", Some("__init__")),
+
+            // NumPy factory functions
            PrimDef::FunNpNDArray => fun("np_ndarray", None),
            PrimDef::FunNpEmpty => fun("np_empty", None),
            PrimDef::FunNpZeros => fun("np_zeros", None),
@ -200,26 +225,20 @@ impl PrimDef {
            PrimDef::FunNpArray => fun("np_array", None),
            PrimDef::FunNpEye => fun("np_eye", None),
            PrimDef::FunNpIdentity => fun("np_identity", None),
-            PrimDef::FunRound => fun("round", None),
-            PrimDef::FunRound64 => fun("round64", None),
+
+            // NumPy view functions
+            PrimDef::FunNpReshape => fun("np_reshape", None),
+
+            // Miscellaneous NumPy & SciPy functions
            PrimDef::FunNpRound => fun("np_round", None),
-            PrimDef::FunRangeInit => fun("range.__init__", Some("__init__")),
-            PrimDef::FunStr => fun("str", None),
-            PrimDef::FunBool => fun("bool", None),
-            PrimDef::FunFloor => fun("floor", None),
-            PrimDef::FunFloor64 => fun("floor64", None),
            PrimDef::FunNpFloor => fun("np_floor", None),
-            PrimDef::FunCeil => fun("ceil", None),
-            PrimDef::FunCeil64 => fun("ceil64", None),
            PrimDef::FunNpCeil => fun("np_ceil", None),
-            PrimDef::FunLen => fun("len", None),
-            PrimDef::FunMin => fun("min", None),
            PrimDef::FunNpMin => fun("np_min", None),
            PrimDef::FunNpMinimum => fun("np_minimum", None),
-            PrimDef::FunMax => fun("max", None),
+            PrimDef::FunNpArgmin => fun("np_argmin", None),
            PrimDef::FunNpMax => fun("np_max", None),
            PrimDef::FunNpMaximum => fun("np_maximum", None),
-            PrimDef::FunAbs => fun("abs", None),
+            PrimDef::FunNpArgmax => fun("np_argmax", None),
            PrimDef::FunNpIsNan => fun("np_isnan", None),
            PrimDef::FunNpIsInf => fun("np_isinf", None),
            PrimDef::FunNpSin => fun("np_sin", None),
@ -257,7 +276,25 @@ impl PrimDef {
            PrimDef::FunNpLdExp => fun("np_ldexp", None),
            PrimDef::FunNpHypot => fun("np_hypot", None),
            PrimDef::FunNpNextAfter => fun("np_nextafter", None),
-            PrimDef::FunSome => fun("Some", None),
+
+            // Miscellaneous Python & NAC3 functions
+            PrimDef::FunInt32 => fun("int32", None),
+            PrimDef::FunInt64 => fun("int64", None),
+            PrimDef::FunUInt32 => fun("uint32", None),
+            PrimDef::FunUInt64 => fun("uint64", None),
+            PrimDef::FunFloat => fun("float", None),
+            PrimDef::FunRound => fun("round", None),
+            PrimDef::FunRound64 => fun("round64", None),
+            PrimDef::FunStr => fun("str", None),
+            PrimDef::FunBool => fun("bool", None),
+            PrimDef::FunFloor => fun("floor", None),
+            PrimDef::FunFloor64 => fun("floor64", None),
+            PrimDef::FunCeil => fun("ceil", None),
+            PrimDef::FunCeil64 => fun("ceil64", None),
+            PrimDef::FunLen => fun("len", None),
+            PrimDef::FunMin => fun("min", None),
+            PrimDef::FunMax => fun("max", None),
+            PrimDef::FunAbs => fun("abs", None),
        }
    }
 }
@ -408,9 +445,9 @@ impl TopLevelComposer {
        let option = unifier.add_ty(TypeEnum::TObj {
            obj_id: PrimDef::Option.id(),
            fields: vec![
-                (PrimDef::OptionIsSome.simple_name().into(), (is_some_type_fun_ty, true)),
-                (PrimDef::OptionIsNone.simple_name().into(), (is_some_type_fun_ty, true)),
-                (PrimDef::OptionUnwrap.simple_name().into(), (unwrap_fun_ty, true)),
+                (PrimDef::FunOptionIsSome.simple_name().into(), (is_some_type_fun_ty, true)),
+                (PrimDef::FunOptionIsNone.simple_name().into(), (is_some_type_fun_ty, true)),
+                (PrimDef::FunOptionUnwrap.simple_name().into(), (unwrap_fun_ty, true)),
            ]
            .into_iter()
            .collect::<HashMap<_, _>>(),
@ -451,8 +488,8 @@ impl TopLevelComposer {
        let ndarray = unifier.add_ty(TypeEnum::TObj {
            obj_id: PrimDef::NDArray.id(),
            fields: Mapping::from([
-                (PrimDef::NDArrayCopy.simple_name().into(), (ndarray_copy_fun_ty, true)),
-                (PrimDef::NDArrayFill.simple_name().into(), (ndarray_fill_fun_ty, true)),
+                (PrimDef::FunNDArrayCopy.simple_name().into(), (ndarray_copy_fun_ty, true)),
+                (PrimDef::FunNDArrayFill.simple_name().into(), (ndarray_fill_fun_ty, true)),
            ]),
            params: into_var_map([ndarray_dtype_tvar, ndarray_ndims_tvar]),
        });
--- a/nac3core/src/toplevel/snapshots/nac3coretopleveltest__test_analyze__generic_class.snap
+++ b/nac3core/src/toplevel/snapshots/nac3coretopleveltest__test_analyze__generic_class.snap
@ -5,7 +5,7 @@ expression: res_vec
 [
    "Class {\nname: \"Generic_A\",\nancestors: [\"Generic_A[V]\", \"B\"],\nfields: [\"aa\", \"a\"],\nmethods: [(\"__init__\", \"fn[[], none]\"), (\"foo\", \"fn[[b:T], none]\"), (\"fun\", \"fn[[a:int32], V]\")],\ntype_vars: [\"V\"]\n}\n",
    "Function {\nname: \"Generic_A.__init__\",\nsig: \"fn[[], none]\",\nvar_id: []\n}\n",
-    "Function {\nname: \"Generic_A.fun\",\nsig: \"fn[[a:int32], V]\",\nvar_id: [TypeVarId(245)]\n}\n",
+    "Function {\nname: \"Generic_A.fun\",\nsig: \"fn[[a:int32], V]\",\nvar_id: [TypeVarId(248)]\n}\n",
    "Class {\nname: \"B\",\nancestors: [\"B\"],\nfields: [\"aa\"],\nmethods: [(\"__init__\", \"fn[[], none]\"), (\"foo\", \"fn[[b:T], none]\")],\ntype_vars: []\n}\n",
    "Function {\nname: \"B.__init__\",\nsig: \"fn[[], none]\",\nvar_id: []\n}\n",
    "Function {\nname: \"B.foo\",\nsig: \"fn[[b:T], none]\",\nvar_id: []\n}\n",
--- a/nac3core/src/toplevel/snapshots/nac3coretopleveltest__test_analyze__inheritance_override.snap
+++ b/nac3core/src/toplevel/snapshots/nac3coretopleveltest__test_analyze__inheritance_override.snap
@ -7,7 +7,7 @@ expression: res_vec
    "Function {\nname: \"A.__init__\",\nsig: \"fn[[t:T], none]\",\nvar_id: []\n}\n",
    "Function {\nname: \"A.fun\",\nsig: \"fn[[a:int32, b:T], list[virtual[B[bool]]]]\",\nvar_id: []\n}\n",
    "Function {\nname: \"A.foo\",\nsig: \"fn[[c:C], none]\",\nvar_id: []\n}\n",
-    "Class {\nname: \"B\",\nancestors: [\"B[typevar234]\", \"A[float]\"],\nfields: [\"a\", \"b\", \"c\", \"d\"],\nmethods: [(\"__init__\", \"fn[[], none]\"), (\"fun\", \"fn[[a:int32, b:T], list[virtual[B[bool]]]]\"), (\"foo\", \"fn[[c:C], none]\")],\ntype_vars: [\"typevar234\"]\n}\n",
+    "Class {\nname: \"B\",\nancestors: [\"B[typevar237]\", \"A[float]\"],\nfields: [\"a\", \"b\", \"c\", \"d\"],\nmethods: [(\"__init__\", \"fn[[], none]\"), (\"fun\", \"fn[[a:int32, b:T], list[virtual[B[bool]]]]\"), (\"foo\", \"fn[[c:C], none]\")],\ntype_vars: [\"typevar237\"]\n}\n",
    "Function {\nname: \"B.__init__\",\nsig: \"fn[[], none]\",\nvar_id: []\n}\n",
    "Function {\nname: \"B.fun\",\nsig: \"fn[[a:int32, b:T], list[virtual[B[bool]]]]\",\nvar_id: []\n}\n",
    "Class {\nname: \"C\",\nancestors: [\"C\", \"B[bool]\", \"A[float]\"],\nfields: [\"a\", \"b\", \"c\", \"d\", \"e\"],\nmethods: [(\"__init__\", \"fn[[], none]\"), (\"fun\", \"fn[[a:int32, b:T], list[virtual[B[bool]]]]\"), (\"foo\", \"fn[[c:C], none]\")],\ntype_vars: []\n}\n",
--- a/nac3core/src/toplevel/snapshots/nac3coretopleveltest__test_analyze__list_tuple_generic.snap
+++ b/nac3core/src/toplevel/snapshots/nac3coretopleveltest__test_analyze__list_tuple_generic.snap
@ -5,8 +5,8 @@ expression: res_vec
 [
    "Function {\nname: \"foo\",\nsig: \"fn[[a:list[int32], b:tuple[T, float]], A[B, bool]]\",\nvar_id: []\n}\n",
    "Class {\nname: \"A\",\nancestors: [\"A[T, V]\"],\nfields: [\"a\", \"b\"],\nmethods: [(\"__init__\", \"fn[[v:V], none]\"), (\"fun\", \"fn[[a:T], V]\")],\ntype_vars: [\"T\", \"V\"]\n}\n",
-    "Function {\nname: \"A.__init__\",\nsig: \"fn[[v:V], none]\",\nvar_id: [TypeVarId(247)]\n}\n",
-    "Function {\nname: \"A.fun\",\nsig: \"fn[[a:T], V]\",\nvar_id: [TypeVarId(252)]\n}\n",
+    "Function {\nname: \"A.__init__\",\nsig: \"fn[[v:V], none]\",\nvar_id: [TypeVarId(250)]\n}\n",
+    "Function {\nname: \"A.fun\",\nsig: \"fn[[a:T], V]\",\nvar_id: [TypeVarId(255)]\n}\n",
    "Function {\nname: \"gfun\",\nsig: \"fn[[a:A[list[float], int32]], none]\",\nvar_id: []\n}\n",
    "Class {\nname: \"B\",\nancestors: [\"B\"],\nfields: [],\nmethods: [(\"__init__\", \"fn[[], none]\")],\ntype_vars: []\n}\n",
    "Function {\nname: \"B.__init__\",\nsig: \"fn[[], none]\",\nvar_id: []\n}\n",
--- a/nac3core/src/toplevel/snapshots/nac3coretopleveltest__test_analyze__self1.snap
+++ b/nac3core/src/toplevel/snapshots/nac3coretopleveltest__test_analyze__self1.snap
@ -3,7 +3,7 @@ source: nac3core/src/toplevel/test.rs
 expression: res_vec
 ---
 [
-    "Class {\nname: \"A\",\nancestors: [\"A[typevar233, typevar234]\"],\nfields: [\"a\", \"b\"],\nmethods: [(\"__init__\", \"fn[[a:A[float, bool], b:B], none]\"), (\"fun\", \"fn[[a:A[float, bool]], A[bool, int32]]\")],\ntype_vars: [\"typevar233\", \"typevar234\"]\n}\n",
+    "Class {\nname: \"A\",\nancestors: [\"A[typevar236, typevar237]\"],\nfields: [\"a\", \"b\"],\nmethods: [(\"__init__\", \"fn[[a:A[float, bool], b:B], none]\"), (\"fun\", \"fn[[a:A[float, bool]], A[bool, int32]]\")],\ntype_vars: [\"typevar236\", \"typevar237\"]\n}\n",
    "Function {\nname: \"A.__init__\",\nsig: \"fn[[a:A[float, bool], b:B], none]\",\nvar_id: []\n}\n",
    "Function {\nname: \"A.fun\",\nsig: \"fn[[a:A[float, bool]], A[bool, int32]]\",\nvar_id: []\n}\n",
    "Class {\nname: \"B\",\nancestors: [\"B\", \"A[int64, bool]\"],\nfields: [\"a\", \"b\"],\nmethods: [(\"__init__\", \"fn[[], none]\"), (\"fun\", \"fn[[a:A[float, bool]], A[bool, int32]]\"), (\"foo\", \"fn[[b:B], B]\"), (\"bar\", \"fn[[a:A[list[B], int32]], tuple[A[virtual[A[B, int32]], bool], B]]\")],\ntype_vars: []\n}\n",
--- a/nac3core/src/toplevel/snapshots/nac3coretopleveltest__test_analyze__simple_class_compose.snap
+++ b/nac3core/src/toplevel/snapshots/nac3coretopleveltest__test_analyze__simple_class_compose.snap
@ -6,12 +6,12 @@ expression: res_vec
    "Class {\nname: \"A\",\nancestors: [\"A\"],\nfields: [\"a\"],\nmethods: [(\"__init__\", \"fn[[], none]\"), (\"fun\", \"fn[[b:B], none]\"), (\"foo\", \"fn[[a:T, b:V], none]\")],\ntype_vars: []\n}\n",
    "Function {\nname: \"A.__init__\",\nsig: \"fn[[], none]\",\nvar_id: []\n}\n",
    "Function {\nname: \"A.fun\",\nsig: \"fn[[b:B], none]\",\nvar_id: []\n}\n",
-    "Function {\nname: \"A.foo\",\nsig: \"fn[[a:T, b:V], none]\",\nvar_id: [TypeVarId(253)]\n}\n",
+    "Function {\nname: \"A.foo\",\nsig: \"fn[[a:T, b:V], none]\",\nvar_id: [TypeVarId(256)]\n}\n",
    "Class {\nname: \"B\",\nancestors: [\"B\", \"C\", \"A\"],\nfields: [\"a\"],\nmethods: [(\"__init__\", \"fn[[], none]\"), (\"fun\", \"fn[[b:B], none]\"), (\"foo\", \"fn[[a:T, b:V], none]\")],\ntype_vars: []\n}\n",
    "Function {\nname: \"B.__init__\",\nsig: \"fn[[], none]\",\nvar_id: []\n}\n",
    "Class {\nname: \"C\",\nancestors: [\"C\", \"A\"],\nfields: [\"a\"],\nmethods: [(\"__init__\", \"fn[[], none]\"), (\"fun\", \"fn[[b:B], none]\"), (\"foo\", \"fn[[a:T, b:V], none]\")],\ntype_vars: []\n}\n",
    "Function {\nname: \"C.__init__\",\nsig: \"fn[[], none]\",\nvar_id: []\n}\n",
    "Function {\nname: \"C.fun\",\nsig: \"fn[[b:B], none]\",\nvar_id: []\n}\n",
    "Function {\nname: \"foo\",\nsig: \"fn[[a:A], none]\",\nvar_id: []\n}\n",
-    "Function {\nname: \"ff\",\nsig: \"fn[[a:T], V]\",\nvar_id: [TypeVarId(261)]\n}\n",
+    "Function {\nname: \"ff\",\nsig: \"fn[[a:T], V]\",\nvar_id: [TypeVarId(264)]\n}\n",
 ]
--- a/nac3core/src/toplevel/type_annotation.rs
+++ b/nac3core/src/toplevel/type_annotation.rs
@ -1,8 +1,9 @@
 use super::*;
 use crate::symbol_resolver::SymbolValue;
-use crate::toplevel::helper::PrimDef;
+use crate::toplevel::helper::{PrimDef, PrimDefDetails};
 use crate::typecheck::typedef::VarMap;
 use nac3parser::ast::Constant;
+use strum::IntoEnumIterator;

 #[derive(Clone, Debug)]
 pub enum TypeAnnotation {
@ -357,6 +358,7 @@ pub fn parse_ast_to_type_annotation_kinds<T, S: std::hash::BuildHasher + Clone>(
 pub fn get_type_from_type_annotation_kinds(
    top_level_defs: &[Arc<RwLock<TopLevelDef>>],
    unifier: &mut Unifier,
+    primitives: &PrimitiveStore,
    ann: &TypeAnnotation,
    subst_list: &mut Option<Vec<Type>>,
 ) -> Result<Type, HashSet<String>> {
@ -379,100 +381,141 @@ pub fn get_type_from_type_annotation_kinds(
            let param_ty = params
                .iter()
                .map(|x| {
-                    get_type_from_type_annotation_kinds(top_level_defs, unifier, x, subst_list)
+                    get_type_from_type_annotation_kinds(
+                        top_level_defs,
+                        unifier,
+                        primitives,
+                        x,
+                        subst_list,
+                    )
                })
                .collect::<Result<Vec<_>, _>>()?;

-            let subst = {
-                // check for compatible range
-                // TODO: if allow type var to be applied(now this disallowed in the parse_to_type_annotation), need more check
-                let mut result = VarMap::new();
-                for (tvar, p) in type_vars.iter().zip(param_ty) {
-                    match unifier.get_ty(*tvar).as_ref() {
-                        TypeEnum::TVar {
-                            id,
-                            range,
-                            fields: None,
-                            name,
-                            loc,
-                            is_const_generic: false,
-                        } => {
-                            let ok: bool = {
-                                // create a temp type var and unify to check compatibility
-                                p == *tvar || {
-                                    let temp = unifier.get_fresh_var_with_range(
-                                        range.as_slice(),
-                                        *name,
-                                        *loc,
-                                    );
-                                    unifier.unify(temp.ty, p).is_ok()
-                                }
-                            };
-                            if ok {
-                                result.insert(*id, p);
-                            } else {
-                                return Err(HashSet::from([format!(
-                                    "cannot apply type {} to type variable with id {:?}",
-                                    unifier.internal_stringify(
-                                        p,
-                                        &mut |id| format!("class{id}"),
-                                        &mut |id| format!("typevar{id}"),
-                                        &mut None
-                                    ),
-                                    *id
-                                )]));
-                            }
-                        }
+            let ty = if let Some(prim_def) = PrimDef::iter().find(|prim| prim.id() == *obj_id) {
+                // Primitive TopLevelDefs do not contain all fields that are present in their Type
+                // counterparts, so directly perform subst on the Type instead.

-                        TypeEnum::TVar { id, range, name, loc, is_const_generic: true, .. } => {
-                            let ty = range[0];
-                            let ok: bool = {
-                                // create a temp type var and unify to check compatibility
-                                p == *tvar || {
-                                    let temp = unifier.get_fresh_const_generic_var(ty, *name, *loc);
-                                    unifier.unify(temp.ty, p).is_ok()
-                                }
-                            };
-                            if ok {
-                                result.insert(*id, p);
-                            } else {
-                                return Err(HashSet::from([format!(
-                                    "cannot apply type {} to type variable {}",
-                                    unifier.stringify(p),
-                                    name.unwrap_or_else(|| format!("typevar{id}").into()),
-                                )]));
-                            }
-                        }
+                let PrimDefDetails::PrimClass { get_ty_fn, .. } = prim_def.details() else {
+                    unreachable!()
+                };

-                        _ => unreachable!("must be generic type var"),
+                let base_ty = get_ty_fn(primitives);
+                let params =
+                    if let TypeEnum::TObj { params, .. } = &*unifier.get_ty_immutable(base_ty) {
+                        params.clone()
+                    } else {
+                        unreachable!()
+                    };
+
+                unifier
+                    .subst(
+                        get_ty_fn(primitives),
+                        &params
+                            .iter()
+                            .zip(param_ty)
+                            .map(|(obj_tv, param)| (*obj_tv.0, param))
+                            .collect(),
+                    )
+                    .unwrap_or(base_ty)
+            } else {
+                let subst = {
+                    // check for compatible range
+                    // TODO: if allow type var to be applied(now this disallowed in the parse_to_type_annotation), need more check
+                    let mut result = VarMap::new();
+                    for (tvar, p) in type_vars.iter().zip(param_ty) {
+                        match unifier.get_ty(*tvar).as_ref() {
+                            TypeEnum::TVar {
+                                id,
+                                range,
+                                fields: None,
+                                name,
+                                loc,
+                                is_const_generic: false,
+                            } => {
+                                let ok: bool = {
+                                    // create a temp type var and unify to check compatibility
+                                    p == *tvar || {
+                                        let temp = unifier.get_fresh_var_with_range(
+                                            range.as_slice(),
+                                            *name,
+                                            *loc,
+                                        );
+                                        unifier.unify(temp.ty, p).is_ok()
+                                    }
+                                };
+                                if ok {
+                                    result.insert(*id, p);
+                                } else {
+                                    return Err(HashSet::from([format!(
+                                        "cannot apply type {} to type variable with id {:?}",
+                                        unifier.internal_stringify(
+                                            p,
+                                            &mut |id| format!("class{id}"),
+                                            &mut |id| format!("typevar{id}"),
+                                            &mut None
+                                        ),
+                                        *id
+                                    )]));
+                                }
+                            }
+
+                            TypeEnum::TVar {
+                                id, range, name, loc, is_const_generic: true, ..
+                            } => {
+                                let ty = range[0];
+                                let ok: bool = {
+                                    // create a temp type var and unify to check compatibility
+                                    p == *tvar || {
+                                        let temp =
+                                            unifier.get_fresh_const_generic_var(ty, *name, *loc);
+                                        unifier.unify(temp.ty, p).is_ok()
+                                    }
+                                };
+                                if ok {
+                                    result.insert(*id, p);
+                                } else {
+                                    return Err(HashSet::from([format!(
+                                        "cannot apply type {} to type variable {}",
+                                        unifier.stringify(p),
+                                        name.unwrap_or_else(|| format!("typevar{id}").into()),
+                                    )]));
+                                }
+                            }
+
+                            _ => unreachable!("must be generic type var"),
+                        }
+                    }
+                    result
+                };
+                // Class Attributes keep a copy with Class Definition and are not added to objects
+                let mut tobj_fields = methods
+                    .iter()
+                    .map(|(name, ty, _)| {
+                        let subst_ty = unifier.subst(*ty, &subst).unwrap_or(*ty);
+                        // methods are immutable
+                        (*name, (subst_ty, false))
+                    })
+                    .collect::<HashMap<_, _>>();
+                tobj_fields.extend(fields.iter().map(|(name, ty, mutability)| {
+                    let subst_ty = unifier.subst(*ty, &subst).unwrap_or(*ty);
+                    (*name, (subst_ty, *mutability))
+                }));
+                let need_subst = !subst.is_empty();
+                let ty = unifier.add_ty(TypeEnum::TObj {
+                    obj_id: *obj_id,
+                    fields: tobj_fields,
+                    params: subst,
+                });
+
+                if need_subst {
+                    if let Some(wl) = subst_list.as_mut() {
+                        wl.push(ty);
                    }
                }
-                result
+
+                ty
            };
-            // Class Attributes keep a copy with Class Definition and are not added to objects
-            let mut tobj_fields = methods
-                .iter()
-                .map(|(name, ty, _)| {
-                    let subst_ty = unifier.subst(*ty, &subst).unwrap_or(*ty);
-                    // methods are immutable
-                    (*name, (subst_ty, false))
-                })
-                .collect::<HashMap<_, _>>();
-            tobj_fields.extend(fields.iter().map(|(name, ty, mutability)| {
-                let subst_ty = unifier.subst(*ty, &subst).unwrap_or(*ty);
-                (*name, (subst_ty, *mutability))
-            }));
-            let need_subst = !subst.is_empty();
-            let ty = unifier.add_ty(TypeEnum::TObj {
-                obj_id: *obj_id,
-                fields: tobj_fields,
-                params: subst,
-            });
-            if need_subst {
-                if let Some(wl) = subst_list.as_mut() {
-                    wl.push(ty);
-                }
-            }
+
            Ok(ty)
        }
        TypeAnnotation::Primitive(ty) | TypeAnnotation::TypeVar(ty) => Ok(*ty),
@ -490,6 +533,7 @@ pub fn get_type_from_type_annotation_kinds(
            let ty = get_type_from_type_annotation_kinds(
                top_level_defs,
                unifier,
+                primitives,
                ty.as_ref(),
                subst_list,
            )?;
@ -499,7 +543,13 @@ pub fn get_type_from_type_annotation_kinds(
            let tys = tys
                .iter()
                .map(|x| {
-                    get_type_from_type_annotation_kinds(top_level_defs, unifier, x, subst_list)
+                    get_type_from_type_annotation_kinds(
+                        top_level_defs,
+                        unifier,
+                        primitives,
+                        x,
+                        subst_list,
+                    )
                })
                .collect::<Result<Vec<_>, _>>()?;
            Ok(unifier.add_ty(TypeEnum::TTuple { ty: tys }))
--- a/nac3core/src/typecheck/type_inferencer/mod.rs
+++ b/nac3core/src/typecheck/type_inferencer/mod.rs
@ -389,7 +389,7 @@ impl<'a> Fold<()> for Inferencer<'a> {
            }
            ast::StmtKind::Assign { targets, value, .. } => {
                for target in targets {
-                    self.unify(target.custom.unwrap(), value.custom.unwrap(), &target.location)?;
+                    self.fold_assign(target, value)?;
                }
            }
            ast::StmtKind::Raise { exc, cause, .. } => {
@ -398,7 +398,10 @@ impl<'a> Fold<()> for Inferencer<'a> {
                }
                if let Some(exc) = exc {
                    self.virtual_checks.push((
-                        exc.custom.unwrap(),
+                        match &*self.unifier.get_ty(exc.custom.unwrap()) {
+                            TypeEnum::TFunc(sign) => sign.ret,
+                            _ => exc.custom.unwrap(),
+                        },
                        self.primitives.exception,
                        exc.location,
                    ));
@ -1387,6 +1390,55 @@ impl<'a> Inferencer<'a> {
            }));
        }

+        // Handle `np.reshape(<array>, <shape>)`
+        if ["np_reshape".into()].contains(id) && args.len() == 2 {
+            // Extract arguments
+            let array_expr = args.remove(0);
+            let shape_expr = args.remove(0);
+
+            // Fold `<array>`
+            let array = self.fold_expr(array_expr)?;
+            let array_ty = array.custom.unwrap();
+            let (array_dtype, _) = unpack_ndarray_var_tys(self.unifier, array_ty);
+
+            // Fold `<shape>`
+            let (target_ndims, target_shape) =
+                self.fold_numpy_function_call_shape_argument(*id, 0, shape_expr)?;
+            let target_shape_ty = target_shape.custom.unwrap();
+            // ... and deduce the return type of the call
+            let target_ndims_ty =
+                self.unifier.get_fresh_literal(vec![SymbolValue::U64(target_ndims)], None);
+            let ret = make_ndarray_ty(
+                self.unifier,
+                self.primitives,
+                Some(array_dtype),
+                Some(target_ndims_ty),
+            );
+
+            let custom = self.unifier.add_ty(TypeEnum::TFunc(FunSignature {
+                args: vec![
+                    FuncArg { name: "array".into(), ty: array_ty, default_value: None },
+                    FuncArg { name: "shape".into(), ty: target_shape_ty, default_value: None },
+                ],
+                ret,
+                vars: VarMap::new(),
+            }));
+
+            return Ok(Some(Located {
+                location,
+                custom: Some(ret),
+                node: ExprKind::Call {
+                    func: Box::new(Located {
+                        custom: Some(custom),
+                        location: func.location,
+                        node: ExprKind::Name { id: *id, ctx: *ctx },
+                    }),
+                    args: vec![array, target_shape],
+                    keywords: vec![],
+                },
+            }));
+        }
+
        // 2-argument ndarray n-dimensional creation functions
        if id == &"np_full".into() && args.len() == 2 {
            let ExprKind::List { elts, .. } = &args[0].node else {
@ -2107,4 +2159,58 @@ impl<'a> Inferencer<'a> {
        self.constrain(body.custom.unwrap(), orelse.custom.unwrap(), &body.location)?;
        Ok(body.custom.unwrap())
    }
+
+    fn fold_assign(
+        &mut self,
+        target: &ast::Expr<Option<Type>>,
+        value: &ast::Expr<Option<Type>>,
+    ) -> Result<(), HashSet<String>> {
+        let target_ty = target.custom.unwrap();
+        let value_ty = value.custom.unwrap();
+
+        match (&target.node, &*self.unifier.get_ty(target_ty)) {
+            (ExprKind::Subscript { .. }, TypeEnum::TObj { obj_id: target_obj_id, .. })
+                if *target_obj_id == self.primitives.ndarray.obj_id(self.unifier).unwrap() =>
+            {
+                // Pattern match expressions like `my_ndarray[slices] = value`.
+                // TODO: `(my_ndarray[slices1], my_ndarray[slices2]) = (value1, value2)` are not supported for now.
+
+                // Suppose `my_ndarray` has type `ndarray[target_dtype, ndims]`
+                // value's type could be one of the following:
+                //   Case 1. `target_dtype`
+                //   Case 2. `ndarray[target_dtype, ?]`
+                //   Case 3. list, tuple, iterables (TODO: NOT IMPLEMENTED)
+
+                let (target_dtype, _) = unpack_ndarray_var_tys(self.unifier, target_ty);
+
+                // Typecheck `value_ty`
+                match &*self.unifier.get_ty(value_ty) {
+                    TypeEnum::TObj { obj_id: value_obj_id, .. }
+                        if *value_obj_id
+                            == self.primitives.ndarray.obj_id(self.unifier).unwrap() =>
+                    {
+                        // Case 2
+                        // - `dtype` of `target_ty` and `value_ty` must unify.
+                        // - `ndims` of `value_ty` is ignored.
+                        let (value_dtype, _) = unpack_ndarray_var_tys(self.unifier, value_ty);
+
+                        self.unify(target_dtype, value_dtype, &target.location)?;
+                    }
+                    _ => {
+                        // If `value_ty` is not an ndarray, simply typecheck as through it has to be Case 1.
+                        self.unify(target_dtype, value_ty, &target.location)?;
+                    }
+                }
+            }
+            _ => {
+                // To handle
+                //   - variable assignments `target = value`
+                //   - and attribute assignments `target.my_attr = value`
+                //
+                // For these cases in nac3core, types of LHS and RHS must unify
+                self.unify(target_ty, value_ty, &target.location)?;
+            }
+        }
+        Ok(())
+    }
 }
--- a/nac3standalone/demo/check_demo.sh
+++ b/nac3standalone/demo/check_demo.sh
@ -14,12 +14,21 @@ while [ $# -gt 1 ]; do
 done
 demo="$1"

-echo -n "Checking $demo... "
-./interpret_demo.py "$demo" > interpreted.log
-./run_demo.sh --out run.log "${nac3args[@]}" "$demo"
-./run_demo.sh --lli --out run_lli.log "${nac3args[@]}" "$demo"
-diff -Nau interpreted.log run.log
-diff -Nau interpreted.log run_lli.log
-echo "ok"
+echo "### Checking $demo..."

-rm -f interpreted.log run.log run_lli.log
+# Get reference output
+echo ">>>>>> Running $demo with the Python interpreter"
+./interpret_demo.py "$demo" > interpreted.log
+
+echo "...... Trying NAC3's 32-bit code generator output"
+./run_demo.sh -i386 --out run_32.log "${nac3args[@]}" "$demo"
+diff -Nau interpreted.log run_32.log
+
+echo "...... Trying NAC3's 64-bit code generator output"
+./run_demo.sh --out run_64.log "${nac3args[@]}" "$demo"
+diff -Nau interpreted.log run_64.log
+
+echo "...... OK"
+
+rm -f interpreted.log \
+  run_32.log run_64.log
--- a/nac3standalone/demo/demo.c
+++ b/nac3standalone/demo/demo.c
@ -6,8 +6,6 @@
 #include <stdlib.h>
 #include <string.h>

-#define usize size_t
-
 double dbl_nan(void) {
  return NAN;
 }
@ -64,14 +62,14 @@ void output_asciiart(int32_t x) {

 struct cslice {
    void *data;
-    usize len;
+    size_t len;
 };

 void output_int32_list(struct cslice *slice) {
    const int32_t *data = (int32_t *) slice->data;

    putchar('[');
-    for (usize i = 0; i < slice->len; ++i) {
+    for (size_t i = 0; i < slice->len; ++i) {
        if (i == slice->len - 1) {
            printf("%d", data[i]);
        } else {
@ -85,7 +83,7 @@ void output_int32_list(struct cslice *slice) {
 void output_str(struct cslice *slice) {
    const char *data = (const char *) slice->data;

-    for (usize i = 0; i < slice->len; ++i) {
+    for (size_t i = 0; i < slice->len; ++i) {
        putchar(data[i]);
    }
 }
@ -107,8 +105,25 @@ uint32_t __nac3_personality(uint32_t state, uint32_t exception_object, uint32_t
    __builtin_unreachable();
 }

-uint32_t __nac3_raise(uint32_t state, uint32_t exception_object, uint32_t context) {
-    printf("__nac3_raise(state: %u, exception_object: %u, context: %u)\n", state, exception_object, context);
+// See `struct Exception<'a>` in
+// https://github.com/m-labs/artiq/blob/master/artiq/firmware/libeh/eh_artiq.rs
+struct Exception {
+    uint32_t id;
+    struct cslice file;
+    uint32_t line;
+    uint32_t column;
+    struct cslice function;
+    struct cslice message;
+    int64_t param[3];
+};
+
+uint32_t __nac3_raise(struct Exception* e) {
+    printf("__nac3_raise called. Exception details:\n");
+    printf("          ID: %"PRIu32"\n", e->id);
+    printf("    Location: %*s:%"PRIu32":%"PRIu32"\n" , (int) e->file.len, (const char*) e->file.data, e->line, e->column);
+    printf("    Function: %*s\n" , (int) e->function.len, (const char*) e->function.data);
+    printf("     Message: \"%*s\"\n" , (int) e->message.len, (const char*) e->message.data);
+    printf("      Params: {0}=%"PRId64", {1}=%"PRId64", {2}=%"PRId64"\n", e->param[0], e->param[1], e->param[2]);
    exit(101);
    __builtin_unreachable();
 }
--- a/nac3standalone/demo/interpret_demo.py
+++ b/nac3standalone/demo/interpret_demo.py
@ -167,7 +167,7 @@ def patch(module):
    module.ceil64 = _ceil
    module.np_ceil = np.ceil

-    # NumPy ndarray functions
+    # NumPy NDArray factory functions
    module.ndarray = NDArray
    module.np_ndarray = np.ndarray
    module.np_empty = np.empty
@ -178,13 +178,18 @@ def patch(module):
    module.np_identity = np.identity
    module.np_array = np.array

+    # NumPy view functions
+    module.np_reshape = np.reshape
+
    # NumPy Math functions
    module.np_isnan = np.isnan
    module.np_isinf = np.isinf
    module.np_min = np.min
    module.np_minimum = np.minimum
+    module.np_argmin = np.argmin
    module.np_max = np.max
    module.np_maximum = np.maximum
+    module.np_argmax = np.argmax
    module.np_sin = np.sin
    module.np_cos = np.cos
    module.np_exp = np.exp
@ -216,7 +221,7 @@ def patch(module):
    module.np_hypot = np.hypot
    module.np_nextafter = np.nextafter

-    # SciPy Math Functions
+    # SciPy Math functions
    module.sp_spec_erf = special.erf
    module.sp_spec_erfc = special.erfc
    module.sp_spec_gamma = special.gamma
@ -224,15 +229,6 @@ def patch(module):
    module.sp_spec_j0 = special.j0
    module.sp_spec_j1 = special.j1

-    # NumPy NDArray Functions
-    module.np_ndarray = np.ndarray
-    module.np_empty = np.empty
-    module.np_zeros = np.zeros
-    module.np_ones = np.ones
-    module.np_full = np.full
-    module.np_eye = np.eye
-    module.np_identity = np.identity
-
 def file_import(filename, prefix="file_import_"):
    filename = pathlib.Path(filename)
    modname = prefix + filename.stem
--- a/nac3standalone/demo/run_demo.sh
+++ b/nac3standalone/demo/run_demo.sh
@ -11,19 +11,19 @@ declare -a nac3args
 while [ $# -ge 1 ]; do
  case "$1" in
    --help)
-      echo "Usage: run_demo.sh [--help] [--out OUTFILE] [--lli] [--debug] -- [NAC3ARGS...]"
+      echo "Usage: run_demo.sh [--help] [--out OUTFILE] [--debug] [-i386] -- [NAC3ARGS...]"
      exit
      ;;
    --out)
      shift
      outfile="$1"
      ;;
-    --lli)
-      use_lli=1
-      ;;
    --debug)
      debug=1
      ;;
+    -i386)
+      i386=1
+      ;;
    --)
      shift
      break
@ -50,29 +50,23 @@ else
 fi

 rm -f ./*.o ./*.bc demo
-if [ -z "$use_lli" ]; then
+
+if [ -z "$i386" ]; then
  $nac3standalone "${nac3args[@]}"

  clang -c -std=gnu11 -Wall -Wextra -O3 -o demo.o demo.c
-  clang -lm -o demo module.o demo.o
-
-  if [ -z "$outfile" ]; then
-    ./demo
-  else
-    ./demo > "$outfile"
-  fi
+  clang -lm -Wl,--no-warn-search-mismatch -o demo module.o demo.o
 else
-  $nac3standalone --emit-llvm "${nac3args[@]}"
+   # Enable SSE2 to avoid rounding errors with X87's 80-bit fp precision computations

-  clang -c -std=gnu11 -Wall -Wextra -O3 -emit-llvm -o demo.bc demo.c
+   $nac3standalone --triple i386-pc-linux-gnu --target-features +sse2 "${nac3args[@]}"

-  shopt -s nullglob
-  llvm-link -o nac3out.bc module*.bc main.bc
-  shopt -u nullglob
-
-  if [ -z "$outfile" ]; then
-    lli --extra-module demo.bc --extra-module irrt.bc nac3out.bc
-  else
-    lli --extra-module demo.bc --extra-module irrt.bc nac3out.bc > "$outfile"
-  fi
+   clang -m32 -c -std=gnu11 -Wall -Wextra -O3 -msse2 -o demo.o demo.c
+   clang -m32 -lm -Wl,--no-warn-search-mismatch -o demo module.o demo.o
+fi
+
+if [ -z "$outfile" ]; then
+  ./demo
+else
+  ./demo > "$outfile"
 fi
--- a/nac3standalone/demo/src/ndarray.py
+++ b/nac3standalone/demo/src/ndarray.py
@ -867,6 +867,13 @@ def test_ndarray_minimum_broadcast_rhs_scalar():
    output_ndarray_float_2(min_x_zeros)
    output_ndarray_float_2(min_x_ones)

+def test_ndarray_argmin():
+    x = np_array([[1., 2.], [3., 4.]])
+    y = np_argmin(x)
+
+    output_ndarray_float_2(x)
+    output_int64(y)
+
 def test_ndarray_max():
    x = np_identity(2)
    y = np_max(x)
@ -910,6 +917,13 @@ def test_ndarray_maximum_broadcast_rhs_scalar():
    output_ndarray_float_2(max_x_zeros)
    output_ndarray_float_2(max_x_ones)

+def test_ndarray_argmax():
+    x = np_array([[1., 2.], [3., 4.]])
+    y = np_argmax(x)
+
+    output_ndarray_float_2(x)
+    output_int64(y)
+
 def test_ndarray_abs():
    x = np_identity(2)
    y = abs(x)
@ -1524,11 +1538,13 @@ def run() -> int32:
    test_ndarray_minimum_broadcast()
    test_ndarray_minimum_broadcast_lhs_scalar()
    test_ndarray_minimum_broadcast_rhs_scalar()
+    test_ndarray_argmin()
    test_ndarray_max()
    test_ndarray_maximum()
    test_ndarray_maximum_broadcast()
    test_ndarray_maximum_broadcast_lhs_scalar()
    test_ndarray_maximum_broadcast_rhs_scalar()
+    test_ndarray_argmax()
    test_ndarray_abs()
    test_ndarray_isnan()
    test_ndarray_isinf()
--- a/nac3standalone/src/main.rs
+++ b/nac3standalone/src/main.rs
@ -9,15 +9,11 @@
 #![allow(clippy::too_many_lines, clippy::wildcard_imports)]

 use clap::Parser;
+use inkwell::context::Context;
 use inkwell::{
    memory_buffer::MemoryBuffer, passes::PassBuilderOptions, support::is_multithreaded, targets::*,
    OptimizationLevel,
 };
-use parking_lot::{Mutex, RwLock};
-use std::collections::HashSet;
-use std::num::NonZeroUsize;
-use std::{collections::HashMap, fs, path::Path, sync::Arc};
-
 use nac3core::{
    codegen::{
        concrete_type::ConcreteTypeStore, irrt::load_irrt, CodeGenLLVMOptions,
@ -39,6 +35,10 @@ use nac3parser::{
    ast::{Constant, Expr, ExprKind, StmtKind, StrRef},
    parser,
 };
+use parking_lot::{Mutex, RwLock};
+use std::collections::HashSet;
+use std::num::NonZeroUsize;
+use std::{collections::HashMap, fs, path::Path, sync::Arc};

 mod basic_symbol_resolver;
 use basic_symbol_resolver::*;
@ -113,7 +113,9 @@ fn handle_typevar_definition(
                        x,
                        HashMap::new(),
                    )?;
-                    get_type_from_type_annotation_kinds(def_list, unifier, &ty, &mut None)
+                    get_type_from_type_annotation_kinds(
+                        def_list, unifier, primitives, &ty, &mut None,
+                    )
                })
                .collect::<Result<Vec<_>, _>>()?;
            let loc = func.location;
@ -152,7 +154,7 @@ fn handle_typevar_definition(
                HashMap::new(),
            )?;
            let constraint =
-                get_type_from_type_annotation_kinds(def_list, unifier, &ty, &mut None)?;
+                get_type_from_type_annotation_kinds(def_list, unifier, primitives, &ty, &mut None)?;
            let loc = func.location;

            Ok(unifier.get_fresh_const_generic_var(constraint, Some(generic_name), Some(loc)).ty)
@ -239,8 +241,6 @@ fn handle_assignment_pattern(
 }

 fn main() {
-    const SIZE_T: u32 = usize::BITS;
-
    let cli = CommandLineArgs::parse();
    let CommandLineArgs { file_name, threads, opt_level, emit_llvm, triple, mcpu, target_features } =
        cli;
@ -273,6 +273,24 @@ fn main() {
        _ => OptimizationLevel::Aggressive,
    };

+    let target_machine_options = CodeGenTargetMachineOptions {
+        triple,
+        cpu: mcpu,
+        features: target_features,
+        reloc_mode: RelocMode::PIC,
+        ..host_target_machine
+    };
+
+    let size_t = Context::create()
+        .ptr_sized_int_type(
+            &target_machine_options
+                .create_target_machine(opt_level)
+                .map(|tm| tm.get_target_data())
+                .unwrap(),
+            None,
+        )
+        .get_bit_width();
+
    let program = match fs::read_to_string(file_name.clone()) {
        Ok(program) => program,
        Err(err) => {
@ -281,9 +299,9 @@ fn main() {
        }
    };

-    let primitive: PrimitiveStore = TopLevelComposer::make_primitives(SIZE_T).0;
+    let primitive: PrimitiveStore = TopLevelComposer::make_primitives(size_t).0;
    let (mut composer, builtins_def, builtins_ty) =
-        TopLevelComposer::new(vec![], ComposerConfig::default(), SIZE_T);
+        TopLevelComposer::new(vec![], ComposerConfig::default(), size_t);

    let internal_resolver: Arc<ResolverInternal> = ResolverInternal {
        id_to_type: builtins_ty.into(),
@ -371,16 +389,7 @@ fn main() {
        instance_to_stmt[""].clone()
    };

-    let llvm_options = CodeGenLLVMOptions {
-        opt_level,
-        target: CodeGenTargetMachineOptions {
-            triple,
-            cpu: mcpu,
-            features: target_features,
-            reloc_mode: RelocMode::PIC,
-            ..host_target_machine
-        },
-    };
+    let llvm_options = CodeGenLLVMOptions { opt_level, target: target_machine_options };

    let task = CodeGenTask {
        subst: Vec::default(),
@ -403,7 +412,7 @@ fn main() {
        membuffer.lock().push(buffer);
    })));
    let threads = (0..threads)
-        .map(|i| Box::new(DefaultCodeGenerator::new(format!("module{i}"), SIZE_T)))
+        .map(|i| Box::new(DefaultCodeGenerator::new(format!("module{i}"), size_t)))
        .collect();
    let (registry, handles) = WorkerRegistry::create_workers(threads, top_level, &llvm_options, &f);
    registry.add_task(task);
--- a/nix/windows/default.nix
+++ b/nix/windows/default.nix
@ -81,7 +81,6 @@ in rec {
    ''
    mkdir -p $out/bin
    ln -s ${llvm-nac3}/bin/clang.exe $out/bin/clang-irrt.exe
-    ln -s ${llvm-nac3}/bin/clang.exe $out/bin/clang-irrt-test.exe
    ln -s ${llvm-nac3}/bin/llvm-as.exe $out/bin/llvm-as-irrt.exe
    '';
  nac3artiq = pkgs.rustPlatform.buildRustPackage {
Author	SHA1	Message	Date
lyken	2ab7b299b8	core/ndstrides: refactor numpy indexing	2024-07-31 09:53:15 +08:00
lyken	86b0d31290	core/ndstrides: pub ScalarOrNDArray::to_basic_value_enum	2024-07-31 09:53:15 +08:00
lyken	6369db94ab	core/codegen: gen_assign to take in value_ty	2024-07-31 09:53:15 +08:00
lyken	3d8240259c	core/typecheck: Inferencer allow heterogenerous assignemnt	2024-07-31 09:53:15 +08:00
lyken	e4f6adb1ec	core/ndstrides: add numpy broadcasting utils	2024-07-31 09:53:15 +08:00
lyken	eb295cf7e4	core/ndstrides: implement numpy broadcasting IRRT	2024-07-31 09:53:15 +08:00
lyken	7501a086d0	core/irrt: print_value add bool	2024-07-31 09:53:15 +08:00
lyken	fb54d5d112	core/ndstrides: add TODO in np_reshape	2024-07-31 09:53:15 +08:00
lyken	3dc4b17310	core/ndstrides: introduce NDArrayObject & refactor reshape	2024-07-31 09:53:15 +08:00
lyken	7436513b64	core/model: add util.rs & gen_model_memcpy	2024-07-31 09:53:15 +08:00
lyken	7e056b9747	core/ndstrides: fix alloca_ndarray comment	2024-07-31 09:53:15 +08:00
lyken	ac7cc15d90	core/ndstrides: remove unnecessary Result<_, String>	2024-07-31 09:53:15 +08:00
lyken	28e6f23034	core/ndstrides: rewrite and fix np_reshape() bug Data content should be copied and strides should be updated after negative indices are resolved.	2024-07-31 09:53:15 +08:00
lyken	dfb8bf9748	core/ndstrides: fix and rewrite is_c_contiguous	2024-07-31 09:53:15 +08:00
lyken	d5880b119a	core/ndstrides: move functions to numpy_new/util.rs	2024-07-31 09:53:15 +08:00
lyken	2747869a45	core/ndstrides: implement general ndarray reshaping	2024-07-31 09:53:15 +08:00
lyken	bd5cb14d0d	core/ndstrides: implement general ndarray basic indexing	2024-07-31 09:53:15 +08:00
lyken	4b14609342	core/ndstrides: implement IRRT slice Needed by ndarray indexing	2024-07-31 09:53:15 +08:00
lyken	2211c4d852	core/ndstrides: implement gen_foreach_ndarray_elements & np_{empty,ndarray,zeros,ones,full}	2024-07-31 09:53:15 +08:00
lyken	5b9ac9b09c	core/ndstrides: implement ndarray len()	2024-07-31 09:53:15 +08:00
lyken	02e3ddfce6	core: make get_llvm_type return new NDArray with strides NOTE: All old numpy functions are now impossible to run, until NDArray with strides is fully implemented.	2024-07-31 09:53:15 +08:00
lyken	8ae9a4294b	core/ndstrides: add basic ndarray IRRT functions	2024-07-31 09:53:15 +08:00
lyken	e5fe86cc93	core/ndstrides: add ArrayWriter & make_shape_writer	2024-07-31 09:53:15 +08:00
lyken	fd3d02bff0	core/ndstrides: add NDArray with strides definition	2024-07-31 09:53:15 +08:00
lyken	7502b14d55	core/irrt: add ErrorContext	2024-07-31 09:53:15 +08:00
lyken	5b7588df75	core/model: add and use CSlice and Exception	2024-07-31 09:53:15 +08:00
lyken	0477e2acfa	core/irrt: comment arrays_match()	2024-07-31 09:53:15 +08:00
lyken	bf0dcf325e	core/irrt: add cstr_utils	2024-07-31 09:53:15 +08:00
lyken	c772fdb83a	core/model: introduce codegen/model	2024-07-31 09:53:15 +08:00
lyken	c1369ea5bd	core/irrt: introduce irrt testing `cargo test -F test` would compile `nac3core/irrt/irrt_test.cpp` targetted to the host machine (it gets to use `std`) and run the test executable.	2024-07-31 09:52:43 +08:00
lyken	ef28138291	core/irrt: split irrt.cpp into headers To scale IRRT implementations	2024-07-31 09:52:43 +08:00
lyken	984843a46a	core/irrt: build.rs capture IR defined constants	2024-07-31 09:52:43 +08:00
lyken	c5626e4947	core/irrt: build.rs capture IR defined types	2024-07-31 09:52:43 +08:00
lyken	e4ba5e6411	core/irrt: reformat	2024-07-31 09:52:43 +08:00
lyken	31d0fdd818	core: add .clang-format	2024-07-31 09:52:43 +08:00
lyken	3f0e7e28b8	core/irrt: comment build.rs & move irrt to its own dir To prepare for future IRRT implementations, and to also make cargo only have to watch a single directory.	2024-07-31 09:52:43 +08:00
David Mak	318a675ea6	standalone: Rename -m32 to -i386	2024-07-29 14:58:58 +08:00
David Mak	32e52ce198	standalone: Revert using uint32_t as slice length Turns out list and str have always been size_t.	2024-07-29 14:58:29 +08:00
Sebastien Bourdeauducq	665ca8e32d	cargo: update dependencies	2024-07-27 22:24:56 +08:00
Sebastien Bourdeauducq	12c12b1d80	flake: update nixpkgs	2024-07-27 22:22:20 +08:00
lyken	72972fa909	core/toplevel: add more numpy categories	2024-07-27 21:57:47 +08:00
lyken	142cd48594	core/toplevel: reorder PrimDef::details	2024-07-27 21:57:47 +08:00
lyken	8adfe781c5	core/toplevel: fix PrimDef method names	2024-07-27 21:57:47 +08:00
lyken	339b74161b	core/toplevel: reorganize PrimDef	2024-07-27 21:57:47 +08:00
David Mak	8c5ba37d09	standalone: Add 32-bit execution tests to check_demo.sh	2024-07-26 13:35:40 +08:00
David Mak	05a8948ff2	core: Minor cleanup to use ListValue APIs	2024-07-26 13:35:40 +08:00
David Mak	6d171ec284	core: Add label name and hooks to gen_for functions	2024-07-26 13:35:40 +08:00
David Mak	0ba68f6657	core: Set target triple and datalayout for each module Fixes an issue with inconsistent pointer sizes causing crashes.	2024-07-26 13:35:40 +08:00
David Mak	693b2a8863	core: Add support for 32-bit size_t on 64-bit targets	2024-07-26 13:35:40 +08:00
David Mak	5faeede0e5	Determine size_t using LLVM target machine	2024-07-26 13:35:38 +08:00
David Mak	266707df9d	standalone: Add support for running 32-bit binaries	2024-07-26 13:32:38 +08:00
David Mak	3d3c258756	standalone: Remove support for --lli	2024-07-26 13:32:38 +08:00
David Mak	ed1182cb24	standalone: Update format specifiers for exceptions Use platform-agnostic identifiers instead.	2024-07-26 13:32:37 +08:00
David Mak	fd025c1137	standalone: Use uint32_t for cslice length Matching the expected type of string and list slices.	2024-07-26 13:32:21 +08:00
David Mak	f139db9af9	meta: Update dependencies	2024-07-26 10:33:02 +08:00
lyken	44487b76ae	standalone: interpret_demo.py remove duplicated section	2024-07-22 17:23:35 +08:00
lyken	1332f113e8	standalone: fix interpret_demo.py comments	2024-07-22 17:06:14 +08:00
Sébastien Bourdeauducq	7632d6f72a	cargo: update dependencies	2024-07-21 11:00:25 +08:00
David Mak	4948395ca2	core/toplevel/type_annotation: Add handling for mismatching class def Primitive types only contain fields in its Type and not its TopLevelDef. This causes primitive object types to lack some fields.	2024-07-19 14:42:14 +08:00
David Mak	3db3061d99	artiq/symbol_resolver: Handle type of zero-length lists	2024-07-19 14:42:14 +08:00
David Mak	51c2175c80	core/codegen/stmt: Convert assertion values to i1	2024-07-19 14:42:14 +08:00
lyken	1a31a50b8a	standalone: fix __nac3_raise def in demo.c	2024-07-17 21:22:08 +08:00
lyken	6c10e3d056	core: cargo clippy	2024-07-12 21:18:53 +08:00
lyken	2dbc1ec659	cargo fmt	2024-07-12 21:16:38 +08:00
Sebastien Bourdeauducq	c80378063a	add np_argmin/argmax to interpret_demo environment	2024-07-12 13:27:52 +02:00
abdul124	513d30152b	core: support raise exception short form	2024-07-12 18:58:34 +08:00
abdul124	45e9360c4d	standalone: Add np_argmax and np_argmin tests	2024-07-12 18:19:56 +08:00
abdul124	2e01b77fc8	core: refactor np_max/np_min functions	2024-07-12 18:18:54 +08:00
abdul124	cea7cade51	core: add np_argmax/np_argmin functions	2024-07-12 18:18:28 +08:00