WIP

core: irrt general numpy broadcasting
core: irrt general numpy slicing
2024-07-10 17:27:10 +08:00 · 2024-07-10 17:05:01 +08:00 · 2024-07-10 14:05:08 +08:00 · 2024-07-10 11:56:31 +08:00 · 2024-07-10 10:17:45 +08:00 · 2024-07-10 10:17:45 +08:00
61 changed files with 8040 additions and 5455 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@ -105,9 +105,9 @@ checksum = "349f9b6a179ed607305526ca489b34ad0a41aed5f7980fa90eb03160b69598fb"

 [[package]]
 name = "bitflags"
-version = "2.5.0"
+version = "2.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cf4b9d6a944f767f8e5e0db018570623c85f3d925ac718db4e06d0187adb21c1"
+checksum = "b048fb63fd8b5923fc5aa7b340d8e156aec7ec02f0c78fa8a6ddc2613f6f71de"

 [[package]]
 name = "byteorder"
@ -117,9 +117,9 @@ checksum = "1fd0f2584146f6f2ef48085050886acf353beff7305ebd1ae69500e27c67f64b"

 [[package]]
 name = "cc"
-version = "1.0.99"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "96c51067fd44124faa7f870b4b1c969379ad32b2ba805aa959430ceaa384f695"
+checksum = "eaff6f8ce506b9773fa786672d63fc7a191ffea1be33f72bbd4aeacefca9ffc8"

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

 [[package]]
 name = "clap"
-version = "4.5.7"
+version = "4.5.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5db83dced34638ad474f39f250d7fea9598bdd239eaced1bdf45d597da0f433f"
+checksum = "64acc1846d54c1fe936a78dc189c34e28d3f5afc348403f28ecf53660b9b8462"
 dependencies = [
 "clap_builder",
 "clap_derive",
@ -139,9 +139,9 @@ dependencies = [

 [[package]]
 name = "clap_builder"
-version = "4.5.7"
+version = "4.5.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f7e204572485eb3fbf28f871612191521df159bc3e15a9f5064c66dba3a8c05f"
+checksum = "6fb8393d67ba2e7bfaf28a23458e4e2b543cc73a99595511eb207fdb8aede942"
 dependencies = [
 "anstream",
 "anstyle",
@ -151,14 +151,14 @@ dependencies = [

 [[package]]
 name = "clap_derive"
-version = "4.5.5"
+version = "4.5.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c780290ccf4fb26629baa7a1081e68ced113f1d3ec302fa5948f1c381ebf06c6"
+checksum = "2bac35c6dafb060fd4d275d9a4ffae97917c13a6327903a8be2153cd964f7085"
 dependencies = [
 "heck 0.5.0",
 "proc-macro2",
 "quote",
- "syn 2.0.66",
+ "syn 2.0.70",
 ]

 [[package]]
@ -270,9 +270,9 @@ dependencies = [

 [[package]]
 name = "either"
-version = "1.12.0"
+version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3dca9240753cf90908d7e4aac30f630662b02aebaa1b58a3cadabdb23385b58b"
+checksum = "60b1af1c220855b6ceac025d3f6ecdd2b7c4894bfe9cd9bda4fbb4bc7c0d4cf0"

 [[package]]
 name = "ena"
@ -421,7 +421,7 @@ checksum = "4fa4d8d74483041a882adaa9a29f633253a66dde85055f0495c121620ac484b2"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.66",
+ "syn 2.0.70",
 ]

 [[package]]
@ -501,9 +501,9 @@ dependencies = [

 [[package]]
 name = "lazy_static"
-version = "1.4.0"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"

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

 [[package]]
 name = "libloading"
-version = "0.8.3"
+version = "0.8.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0c2a198fb6b0eada2a8df47933734e6d35d350665a33a3593d7164fa52c75c19"
+checksum = "e310b3a6b5907f99202fcdb4960ff45b93735d7c7d96b760fcff8db2dc0e103d"
 dependencies = [
 "cfg-if",
 "windows-targets",
@ -568,9 +568,9 @@ dependencies = [

 [[package]]
 name = "log"
-version = "0.4.21"
+version = "0.4.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90ed8c1e510134f979dbc4f070f87d4313098b704861a105fe34231c70a3901c"
+checksum = "a7a70ba024b9dc04c27ea2f0c0548feb474ec5c54bba33a7f72f873a39d07b24"

 [[package]]
 name = "memchr"
@ -749,7 +749,7 @@ dependencies = [
 "phf_shared 0.11.2",
 "proc-macro2",
 "quote",
- "syn 2.0.66",
+ "syn 2.0.70",
 ]

 [[package]]
@ -796,9 +796,9 @@ checksum = "925383efa346730478fb4838dbe9137d2a47675ad789c546d150a6e1dd4ab31c"

 [[package]]
 name = "proc-macro2"
-version = "1.0.85"
+version = "1.0.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "22244ce15aa966053a896d1accb3a6e68469b97c7f33f284b99f0d576879fc23"
+checksum = "5e719e8df665df0d1c8fbfd238015744736151d4445ec0836b8e628aae103b77"
 dependencies = [
 "unicode-ident",
 ]
@ -850,7 +850,7 @@ dependencies = [
 "proc-macro2",
 "pyo3-macros-backend",
 "quote",
- "syn 2.0.66",
+ "syn 2.0.70",
 ]

 [[package]]
@ -863,7 +863,7 @@ dependencies = [
 "proc-macro2",
 "pyo3-build-config",
 "quote",
- "syn 2.0.66",
+ "syn 2.0.70",
 ]

 [[package]]
@ -1029,29 +1029,29 @@ checksum = "61697e0a1c7e512e84a621326239844a24d8207b4669b41bc18b32ea5cbf988b"

 [[package]]
 name = "serde"
-version = "1.0.203"
+version = "1.0.204"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7253ab4de971e72fb7be983802300c30b5a7f0c2e56fab8abfc6a214307c0094"
+checksum = "bc76f558e0cbb2a839d37354c575f1dc3fdc6546b5be373ba43d95f231bf7c12"
 dependencies = [
 "serde_derive",
 ]

 [[package]]
 name = "serde_derive"
-version = "1.0.203"
+version = "1.0.204"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "500cbc0ebeb6f46627f50f3f5811ccf6bf00643be300b4c3eabc0ef55dc5b5ba"
+checksum = "e0cd7e117be63d3c3678776753929474f3b04a43a080c744d6b0ae2a8c28e222"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.66",
+ "syn 2.0.70",
 ]

 [[package]]
 name = "serde_json"
-version = "1.0.117"
+version = "1.0.120"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "455182ea6142b14f93f4bc5320a2b31c1f266b66a4a5c858b013302a5d8cbfc3"
+checksum = "4e0d21c9a8cae1235ad58a00c11cb40d4b1e5c784f1ef2c537876ed6ffd8b7c5"
 dependencies = [
 "itoa",
 "ryu",
@ -1120,9 +1120,9 @@ checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"

 [[package]]
 name = "strum"
-version = "0.26.2"
+version = "0.26.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5d8cec3501a5194c432b2b7976db6b7d10ec95c253208b45f83f7136aa985e29"
+checksum = "8fec0f0aef304996cf250b31b5a10dee7980c85da9d759361292b8bca5a18f06"

 [[package]]
 name = "strum_macros"
@ -1134,7 +1134,7 @@ dependencies = [
 "proc-macro2",
 "quote",
 "rustversion",
- "syn 2.0.66",
+ "syn 2.0.70",
 ]

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

 [[package]]
 name = "syn"
-version = "2.0.66"
+version = "2.0.70"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c42f3f41a2de00b01c0aaad383c5a45241efc8b2d1eda5661812fda5f3cdcff5"
+checksum = "2f0209b68b3613b093e0ec905354eccaedcfe83b8cb37cbdeae64026c3064c16"
 dependencies = [
 "proc-macro2",
 "quote",
@ -1161,9 +1161,9 @@ dependencies = [

 [[package]]
 name = "target-lexicon"
-version = "0.12.14"
+version = "0.12.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e1fc403891a21bcfb7c37834ba66a547a8f402146eba7265b5a6d88059c9ff2f"
+checksum = "4873307b7c257eddcb50c9bedf158eb669578359fb28428bef438fec8e6ba7c2"

 [[package]]
 name = "tempfile"
@ -1218,7 +1218,7 @@ checksum = "46c3384250002a6d5af4d114f2845d37b57521033f30d5c3f46c4d70e1197533"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.66",
+ "syn 2.0.70",
 ]

 [[package]]
@ -1398,9 +1398,9 @@ dependencies = [

 [[package]]
 name = "windows-targets"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6f0713a46559409d202e70e28227288446bf7841d3211583a4b53e3f6d96e7eb"
+checksum = "9b724f72796e036ab90c1021d4780d4d3d648aca59e491e6b98e725b84e99973"
 dependencies = [
 "windows_aarch64_gnullvm",
 "windows_aarch64_msvc",
@ -1414,51 +1414,51 @@ dependencies = [

 [[package]]
 name = "windows_aarch64_gnullvm"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7088eed71e8b8dda258ecc8bac5fb1153c5cffaf2578fc8ff5d61e23578d3263"
+checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"

 [[package]]
 name = "windows_aarch64_msvc"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9985fd1504e250c615ca5f281c3f7a6da76213ebd5ccc9561496568a2752afb6"
+checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"

 [[package]]
 name = "windows_i686_gnu"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "88ba073cf16d5372720ec942a8ccbf61626074c6d4dd2e745299726ce8b89670"
+checksum = "8e9b5ad5ab802e97eb8e295ac6720e509ee4c243f69d781394014ebfe8bbfa0b"

 [[package]]
 name = "windows_i686_gnullvm"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "87f4261229030a858f36b459e748ae97545d6f1ec60e5e0d6a3d32e0dc232ee9"
+checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"

 [[package]]
 name = "windows_i686_msvc"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "db3c2bf3d13d5b658be73463284eaf12830ac9a26a90c717b7f771dfe97487bf"
+checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"

 [[package]]
 name = "windows_x86_64_gnu"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4e4246f76bdeff09eb48875a0fd3e2af6aada79d409d33011886d3e1581517d9"
+checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"

 [[package]]
 name = "windows_x86_64_gnullvm"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "852298e482cd67c356ddd9570386e2862b5673c85bd5f88df9ab6802b334c596"
+checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"

 [[package]]
 name = "windows_x86_64_msvc"
-version = "0.52.5"
+version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bec47e5bfd1bff0eeaf6d8b485cc1074891a197ab4225d504cb7a1ab88b02bf0"
+checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"

 [[package]]
 name = "yaml-rust"
@ -1471,20 +1471,20 @@ dependencies = [

 [[package]]
 name = "zerocopy"
-version = "0.7.34"
+version = "0.7.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ae87e3fcd617500e5d106f0380cf7b77f3c6092aae37191433159dda23cfb087"
+checksum = "1b9b4fd18abc82b8136838da5d50bae7bdea537c574d8dc1a34ed098d6c166f0"
 dependencies = [
 "zerocopy-derive",
 ]

 [[package]]
 name = "zerocopy-derive"
-version = "0.7.34"
+version = "0.7.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "15e934569e47891f7d9411f1a451d947a60e000ab3bd24fbb970f000387d1b3b"
+checksum = "fa4f8080344d4671fb4e831a13ad1e68092748387dfc4f55e356242fae12ce3e"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.66",
+ "syn 2.0.70",
 ]
--- a/flake.lock
+++ b/flake.lock
@ -2,11 +2,11 @@
  "nodes": {
    "nixpkgs": {
      "locked": {
-        "lastModified": 1718530797,
-        "narHash": "sha256-pup6cYwtgvzDpvpSCFh1TEUjw2zkNpk8iolbKnyFmmU=",
+        "lastModified": 1720418205,
+        "narHash": "sha256-cPJoFPXU44GlhWg4pUk9oUPqurPlCFZ11ZQPk21GTPU=",
        "owner": "NixOS",
        "repo": "nixpkgs",
-        "rev": "b60ebf54c15553b393d144357375ea956f89e9a9",
+        "rev": "655a58a72a6601292512670343087c2d75d859c1",
        "type": "github"
      },
      "original": {
--- a/flake.nix
+++ b/flake.nix
@ -13,6 +13,7 @@
          ''
          mkdir -p $out/bin
          ln -s ${pkgs.llvmPackages_14.clang-unwrapped}/bin/clang $out/bin/clang-irrt
+          ln -s ${pkgs.llvmPackages_14.clang}/bin/clang $out/bin/clang-irrt-test
          ln -s ${pkgs.llvmPackages_14.llvm.out}/bin/llvm-as $out/bin/llvm-as-irrt
          '';
        nac3artiq = pkgs.python3Packages.toPythonModule (
@ -23,6 +24,7 @@
            cargoLock = {
              lockFile = ./Cargo.lock;
            };
+            cargoTestFlags = [ "--features" "test" ];
            passthru.cargoLock = cargoLock;
            nativeBuildInputs = [ pkgs.python3 pkgs.llvmPackages_14.clang llvm-tools-irrt pkgs.llvmPackages_14.llvm.out llvm-nac3 ];
            buildInputs = [ pkgs.python3 llvm-nac3 ];
@ -161,7 +163,10 @@
          clippy
          pre-commit
          rustfmt
+          rust-analyzer
        ];
+        # https://nixos.wiki/wiki/Rust#Shell.nix_example
+        RUST_SRC_PATH = "${pkgs.rust.packages.stable.rustPlatform.rustLibSrc}";
      };
      devShells.x86_64-linux.msys2 = pkgs.mkShell {
        name = "nac3-dev-shell-msys2";
--- a/nac3artiq/demo/support_class_attr_issue102.py
+++ b/nac3artiq/demo/support_class_attr_issue102.py
@ -0,0 +1,40 @@
+from min_artiq import *
+from numpy import int32
+
+
+@nac3
+class Demo:
+    attr1: KernelInvariant[int32] = 2
+    attr2: int32 = 4
+    attr3: Kernel[int32]
+
+    @kernel
+    def __init__(self):
+        self.attr3 = 8
+
+
+@nac3
+class NAC3Devices:
+    core: KernelInvariant[Core]
+    attr4: KernelInvariant[int32] = 16
+    
+    def __init__(self):
+        self.core = Core()
+
+    @kernel
+    def run(self):
+        Demo.attr1  # Supported
+        # Demo.attr2  # Field not accessible on Kernel
+        # Demo.attr3  # Only attributes can be accessed in this way
+        # Demo.attr1 = 2  # Attributes are immutable
+
+        self.attr4  # Attributes can be accessed within class
+
+        obj = Demo()
+        obj.attr1  # Attributes can be accessed by class objects
+
+        NAC3Devices.attr4  # Attributes accessible for classes without __init__
+
+
+if __name__ == "__main__":
+    NAC3Devices().run()
--- a/nac3artiq/src/codegen.rs
+++ b/nac3artiq/src/codegen.rs
@ -6,8 +6,8 @@ use nac3core::{
        CodeGenContext, CodeGenerator,
    },
    symbol_resolver::ValueEnum,
-    toplevel::{helper::PrimDef, DefinitionId, GenCall},
-    typecheck::typedef::{FunSignature, FuncArg, Type, TypeEnum, VarMap},
+    toplevel::{helper::PrimDef, numpy::unpack_ndarray_var_tys, DefinitionId, GenCall},
+    typecheck::typedef::{iter_type_vars, FunSignature, FuncArg, Type, TypeEnum, VarMap},
 };

 use nac3parser::ast::{Expr, ExprKind, Located, Stmt, StmtKind, StrRef};
@ -23,7 +23,6 @@ use pyo3::{

 use crate::{symbol_resolver::InnerResolver, timeline::TimeFns};

-use nac3core::toplevel::numpy::unpack_ndarray_var_tys;
 use std::{
    collections::hash_map::DefaultHasher,
    collections::HashMap,
@ -394,9 +393,11 @@ fn gen_rpc_tag(
                    gen_rpc_tag(ctx, *ty, buffer)?;
                }
            }
-            TList { ty } => {
+            TObj { obj_id, params, .. } if *obj_id == PrimDef::List.id() => {
+                let ty = iter_type_vars(params).next().unwrap().ty;
+
                buffer.push(b'l');
-                gen_rpc_tag(ctx, *ty, buffer)?;
+                gen_rpc_tag(ctx, ty, buffer)?;
            }
            TObj { obj_id, .. } if *obj_id == PrimDef::NDArray.id() => {
                let (ndarray_dtype, ndarray_ndims) = unpack_ndarray_var_tys(&mut ctx.unifier, ty);
@ -657,7 +658,7 @@ pub fn attributes_writeback(
                        }
                        if gen_rpc_tag(ctx, *field_ty, &mut scratch_buffer).is_ok() {
                            attributes.push(name.to_string());
-                            let index = ctx.get_attr_index(ty, *name);
+                            let (index, _) = ctx.get_attr_index(ty, *name);
                            values.push((
                                *field_ty,
                                ctx.build_gep_and_load(
@ -675,8 +676,10 @@ pub fn attributes_writeback(
                        host_attributes.append(pydict)?;
                    }
                }
-                TypeEnum::TList { ty: elem_ty } => {
-                    if gen_rpc_tag(ctx, *elem_ty, &mut scratch_buffer).is_ok() {
+                TypeEnum::TObj { obj_id, params, .. } if *obj_id == PrimDef::List.id() => {
+                    let elem_ty = iter_type_vars(params).next().unwrap().ty;
+
+                    if gen_rpc_tag(ctx, elem_ty, &mut scratch_buffer).is_ok() {
                        let pydict = PyDict::new(py);
                        pydict.set_item("obj", val)?;
                        host_attributes.append(pydict)?;
--- a/nac3artiq/src/symbol_resolver.rs
+++ b/nac3artiq/src/symbol_resolver.rs
@ -329,8 +329,19 @@ impl InnerResolver {
            Ok(Ok((primitives.exception, true)))
        } else if ty_id == self.primitive_ids.list {
            // do not handle type var param and concrete check here
+            let list_tvar = if let TypeEnum::TObj { obj_id, params, .. } =
+                &*unifier.get_ty_immutable(primitives.list)
+            {
+                assert_eq!(*obj_id, PrimDef::List.id());
+                iter_type_vars(params).nth(0).unwrap()
+            } else {
+                unreachable!()
+            };
+
            let var = unifier.get_dummy_var().ty;
-            let list = unifier.add_ty(TypeEnum::TList { ty: var });
+            let list = unifier
+                .subst(primitives.list, &into_var_map([TypeVar { id: list_tvar.id, ty: var }]))
+                .unwrap();
            Ok(Ok((list, false)))
        } else if ty_id == self.primitive_ids.ndarray {
            // do not handle type var param and concrete check here
@ -460,7 +471,7 @@ impl InnerResolver {
                };

            match &*unifier.get_ty(origin_ty) {
-                TypeEnum::TList { .. } => {
+                TypeEnum::TObj { obj_id, .. } if *obj_id == PrimDef::List.id() => {
                    if args.len() == 1 {
                        let ty = match self.get_pyty_obj_type(
                            py,
@ -477,7 +488,21 @@ impl InnerResolver {
                                "type list should take concrete parameters in typevar range".into(),
                            ));
                        }
-                        Ok(Ok((unifier.add_ty(TypeEnum::TList { ty: ty.0 }), true)))
+                        let list_tvar = if let TypeEnum::TObj { obj_id, params, .. } =
+                            &*unifier.get_ty_immutable(primitives.list)
+                        {
+                            assert_eq!(*obj_id, PrimDef::List.id());
+                            iter_type_vars(params).nth(0).unwrap()
+                        } else {
+                            unreachable!()
+                        };
+                        let list = unifier
+                            .subst(
+                                primitives.list,
+                                &into_var_map([TypeVar { id: list_tvar.id, ty: ty.0 }]),
+                            )
+                            .unwrap();
+                        Ok(Ok((list, true)))
                    } else {
                        return Ok(Err(format!(
                            "type list needs exactly 1 type parameters, found {}",
@ -627,12 +652,15 @@ impl InnerResolver {
        let pyid_to_def = self.pyid_to_def.read();
        let constructor_ty = pyid_to_def.get(&py_obj_id).and_then(|def_id| {
            defs.iter().find_map(|def| {
-                if let TopLevelDef::Class { object_id, methods, constructor, .. } = &*def.read() {
-                    if object_id == def_id
-                        && constructor.is_some()
-                        && methods.iter().any(|(s, _, _)| s == &"__init__".into())
+                if let Some(rear_guard) = def.try_read() {
+                    if let TopLevelDef::Class { object_id, methods, constructor, .. } = &*rear_guard
                    {
-                        return *constructor;
+                        if object_id == def_id
+                            && constructor.is_some()
+                            && methods.iter().any(|(s, _, _)| s == &"__init__".into())
+                        {
+                            return *constructor;
+                        }
                    }
                }
                None
@ -664,15 +692,38 @@ impl InnerResolver {
            primitives,
        )? {
            Ok(s) => s,
-            Err(e) => return Ok(Err(e)),
+            Err(e) => {
+                // Allow access to Class Attributes of Classes without having to initialize Objects
+                if self.pyid_to_def.read().contains_key(&py_obj_id) {
+                    if let Some(def_id) = self.pyid_to_def.read().get(&py_obj_id).copied() {
+                        let def = defs[def_id.0].read();
+                        let TopLevelDef::Class { object_id, .. } = &*def else {
+                            // only object is supported, functions are not supported
+                            unreachable!("function type is not supported, should not be queried")
+                        };
+
+                        let ty = TypeEnum::TObj {
+                            obj_id: *object_id,
+                            params: VarMap::new(),
+                            fields: HashMap::new(),
+                        };
+                        (unifier.add_ty(ty), true)
+                    } else {
+                        return Ok(Err(e));
+                    }
+                } else {
+                    return Ok(Err(e));
+                }
+            }
        };
        match (&*unifier.get_ty(extracted_ty), inst_check) {
            // do the instantiation for these four types
-            (TypeEnum::TList { ty }, false) => {
+            (TypeEnum::TObj { obj_id, params, .. }, false) if *obj_id == PrimDef::List.id() => {
+                let ty = iter_type_vars(params).nth(0).unwrap().ty;
                let len: usize = self.helper.len_fn.call1(py, (obj,))?.extract(py)?;
                if len == 0 {
                    assert!(matches!(
-                        &*unifier.get_ty(*ty),
+                        &*unifier.get_ty(ty),
                        TypeEnum::TVar { fields: None, range, .. }
                            if range.is_empty()
                    ));
@ -681,8 +732,25 @@ impl InnerResolver {
                    let actual_ty =
                        self.get_list_elem_type(py, obj, len, unifier, defs, primitives)?;
                    match actual_ty {
-                        Ok(t) => match unifier.unify(*ty, t) {
-                            Ok(()) => Ok(Ok(unifier.add_ty(TypeEnum::TList { ty: *ty }))),
+                        Ok(t) => match unifier.unify(ty, t) {
+                            Ok(()) => {
+                                let list_tvar = if let TypeEnum::TObj { obj_id, params, .. } =
+                                    &*unifier.get_ty_immutable(primitives.list)
+                                {
+                                    assert_eq!(*obj_id, PrimDef::List.id());
+                                    iter_type_vars(params).nth(0).unwrap()
+                                } else {
+                                    unreachable!()
+                                };
+                                let list = unifier
+                                    .subst(
+                                        primitives.list,
+                                        &into_var_map([TypeVar { id: list_tvar.id, ty }]),
+                                    )
+                                    .unwrap();
+                                Ok(Ok(list))
+                            }
+
                            Err(e) => Ok(Err(format!(
                                "type error ({}) for the list",
                                e.to_display(unifier)
@ -917,12 +985,11 @@ impl InnerResolver {
            }

            let len: usize = self.helper.len_fn.call1(py, (obj,))?.extract(py)?;
-            let elem_ty = if let TypeEnum::TList { ty } =
-                ctx.unifier.get_ty_immutable(expected_ty).as_ref()
-            {
-                *ty
-            } else {
-                unreachable!("must be list")
+            let elem_ty = match ctx.unifier.get_ty_immutable(expected_ty).as_ref() {
+                TypeEnum::TObj { obj_id, params, .. } if *obj_id == PrimDef::List.id() => {
+                    iter_type_vars(params).nth(0).unwrap().ty
+                }
+                _ => unreachable!("must be list"),
            };
            let ty = ctx.get_llvm_type(generator, elem_ty);
            let size_t = generator.get_size_type(ctx.ctx);
--- a/nac3ast/Cargo.toml
+++ b/nac3ast/Cargo.toml
@ -10,7 +10,7 @@ constant-optimization = ["fold"]
 fold = []

 [dependencies]
-lazy_static = "1.4"
+lazy_static = "1.5"
 parking_lot = "0.12"
 string-interner = "0.17"
 fxhash = "0.2"
--- a/nac3core/Cargo.toml
+++ b/nac3core/Cargo.toml
@ -1,3 +1,6 @@
+[features]
+test = []
+
 [package]
 name = "nac3core"
 version = "0.1.0"
--- a/nac3core/build.rs
+++ b/nac3core/build.rs
@ -7,8 +7,8 @@ use std::{
    process::{Command, Stdio},
 };

-fn main() {
-    const FILE: &str = "src/codegen/irrt/irrt.c";
+fn compile_irrt(irrt_dir: &Path, out_dir: &Path) {
+    let irrt_cpp_path = irrt_dir.join("irrt.cpp");

    /*
     * HACK: Sadly, clang doesn't let us emit generic LLVM bitcode.
@ -16,8 +16,12 @@ fn main() {
     */
    let flags: &[&str] = &[
        "--target=wasm32",
-        FILE,
+        irrt_cpp_path.to_str().unwrap(),
+        "-x",
+        "c++",
        "-fno-discard-value-names",
+        "-fno-exceptions",
+        "-fno-rtti",
        match env::var("PROFILE").as_deref() {
            Ok("debug") => "-O0",
            Ok("release") => "-O3",
@ -27,13 +31,14 @@ fn main() {
        "-S",
        "-Wall",
        "-Wextra",
+        "-Werror=return-type",
+        "-I",
+        irrt_dir.to_str().unwrap(),
        "-o",
        "-",
    ];

-    println!("cargo:rerun-if-changed={FILE}");
-    let out_dir = env::var("OUT_DIR").unwrap();
-    let out_path = Path::new(&out_dir);
+    println!("cargo:rerun-if-changed={}", out_dir.to_str().unwrap());

    let output = Command::new("clang-irrt")
        .args(flags)
@ -48,7 +53,11 @@ fn main() {
    let output = std::str::from_utf8(&output.stdout).unwrap().replace("\r\n", "\n");
    let mut filtered_output = String::with_capacity(output.len());

-    let regex_filter = Regex::new(r"(?ms:^define.*?\}$)|(?m:^declare.*?$)").unwrap();
+    // (?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();
    for f in regex_filter.captures_iter(&output) {
        assert_eq!(f.len(), 1);
        filtered_output.push_str(&f[0]);
@ -61,18 +70,65 @@ fn main() {

    println!("cargo:rerun-if-env-changed=DEBUG_DUMP_IRRT");
    if env::var("DEBUG_DUMP_IRRT").is_ok() {
-        let mut file = File::create(out_path.join("irrt.ll")).unwrap();
+        let mut file = File::create(out_dir.join("irrt.ll")).unwrap();
        file.write_all(output.as_bytes()).unwrap();
-        let mut file = File::create(out_path.join("irrt-filtered.ll")).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")
        .stdin(Stdio::piped())
        .arg("-o")
-        .arg(out_path.join("irrt.bc"))
+        .arg(out_dir.join("irrt.bc"))
        .spawn()
        .unwrap();
    llvm_as.stdin.as_mut().unwrap().write_all(filtered_output.as_bytes()).unwrap();
    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");
+
+    let flags: &[&str] = &[
+        irrt_test_cpp_path.to_str().unwrap(),
+        "-x",
+        "c++",
+        "-I",
+        irrt_dir.to_str().unwrap(),
+        "-g",
+        "-fno-discard-value-names",
+        "-O0",
+        "-Wall",
+        "-Wextra",
+        "-Werror=return-type",
+        "-lm", // for `tgamma()`, `lgamma()`
+        "-o",
+        exe_path.to_str().unwrap(),
+    ];
+
+    Command::new("clang-irrt-test")
+        .args(flags)
+        .output()
+        .map(|o| {
+            assert!(o.status.success(), "{}", std::str::from_utf8(&o.stderr).unwrap());
+            o
+        })
+        .unwrap();
+    println!("cargo:rerun-if-changed={}", out_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);
+
+    // 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);
+    }
+}
--- a/nac3core/irrt/irrt.cpp
+++ b/nac3core/irrt/irrt.cpp
@ -0,0 +1,5 @@
+#include "irrt_everything.hpp"
+
+/*
+    This file will be read by `clang-irrt` to conveniently produce LLVM IR for `nac3core/codegen`.
+*/
--- a/nac3core/irrt/irrt.hpp
+++ b/nac3core/irrt/irrt.hpp
@ -0,0 +1,437 @@
+#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_basic.hpp
+++ b/nac3core/irrt/irrt_basic.hpp
@ -0,0 +1,216 @@
+#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
@ -0,0 +1,14 @@
+#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.
+*/
--- a/nac3core/irrt/irrt_numpy_ndarray.hpp
+++ b/nac3core/irrt/irrt_numpy_ndarray.hpp
@ -0,0 +1,466 @@
+#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
@ -0,0 +1,80 @@
+#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
@ -0,0 +1,658 @@
+// This file will be compiled like a real C++ program,
+// and we do have the luxury to use the standard libraries.
+// That is if the nix flakes do not have issues... especially on msys2...
+#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
+        ```
+    */
+}
+
+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();
+    return 0;
+}
--- a/nac3core/irrt/irrt_typedefs.hpp
+++ b/nac3core/irrt/irrt_typedefs.hpp
@ -0,0 +1,14 @@
+#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
@ -0,0 +1,37 @@
+#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/src/codegen/builtin_fns.rs
+++ b/nac3core/src/codegen/builtin_fns.rs
--- a/nac3core/src/codegen/classes.rs
+++ b/nac3core/src/codegen/classes.rs
@ -1,8 +1,6 @@
 use crate::codegen::{
-    irrt::{call_ndarray_calc_size, call_ndarray_flatten_index},
-    llvm_intrinsics::call_int_umin,
-    stmt::gen_for_callback_incrementing,
-    CodeGenContext, CodeGenerator,
+    llvm_intrinsics::call_int_umin, stmt::gen_for_callback_incrementing, CodeGenContext,
+    CodeGenerator,
 };
 use inkwell::context::Context;
 use inkwell::types::{ArrayType, BasicType, StructType};
@ -12,6 +10,7 @@ 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> {
@ -713,12 +712,25 @@ impl<'ctx> ListValue<'ctx> {
    /// If `size` is [None], the size stored in the field of this instance is used instead.
    pub fn create_data(
        &self,
-        ctx: &CodeGenContext<'ctx, '_>,
+        ctx: &mut CodeGenContext<'ctx, '_>,
        elem_ty: BasicTypeEnum<'ctx>,
        size: Option<IntValue<'ctx>>,
    ) {
        let size = size.unwrap_or_else(|| self.load_size(ctx, None));
-        self.store_data(ctx, ctx.builder.build_array_alloca(elem_ty, size, "").unwrap());
+
+        let data = ctx
+            .builder
+            .build_select(
+                ctx.builder
+                    .build_int_compare(IntPredicate::NE, size, self.llvm_usize.const_zero(), "")
+                    .unwrap(),
+                ctx.builder.build_array_alloca(elem_ty, size, "").unwrap(),
+                elem_ty.ptr_type(AddressSpace::default()).const_zero(),
+                "",
+            )
+            .map(BasicValueEnum::into_pointer_value)
+            .unwrap();
+        self.store_data(ctx, data);
    }

    /// Returns the double-indirection pointer to the `data` array, as if by calling `getelementptr`
@ -1588,7 +1600,8 @@ impl<'ctx> ArrayLikeValue<'ctx> for NDArrayDataProxy<'ctx, '_> {
        ctx: &CodeGenContext<'ctx, '_>,
        generator: &G,
    ) -> IntValue<'ctx> {
-        call_ndarray_calc_size(generator, ctx, &self.as_slice_value(ctx, generator), (None, None))
+        todo!()
+        // call_ndarray_calc_size(generator, ctx, &self.as_slice_value(ctx, generator), (None, None))
    }
 }

@ -1662,17 +1675,19 @@ impl<'ctx, Index: UntypedArrayLikeAccessor<'ctx>> ArrayLikeIndexer<'ctx, Index>
            indices_elem_ty.get_bit_width()
        );

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

-        unsafe {
-            ctx.builder
-                .build_in_bounds_gep(
-                    self.base_ptr(ctx, generator),
-                    &[index],
-                    name.unwrap_or_default(),
-                )
-                .unwrap()
-        }
+        // 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()
+        // }
    }

    fn ptr_offset<G: CodeGenerator + ?Sized>(
@ -1748,3 +1763,307 @@ 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/concrete_type.rs
+++ b/nac3core/src/codegen/concrete_type.rs
@ -47,9 +47,6 @@ pub enum ConcreteTypeEnum {
    TTuple {
        ty: Vec<ConcreteType>,
    },
-    TList {
-        ty: ConcreteType,
-    },
    TObj {
        obj_id: DefinitionId,
        fields: HashMap<StrRef, (ConcreteType, bool)>,
@ -167,9 +164,6 @@ impl ConcreteTypeStore {
                        .map(|t| self.from_unifier_type(unifier, primitives, *t, cache))
                        .collect(),
                },
-                TypeEnum::TList { ty } => ConcreteTypeEnum::TList {
-                    ty: self.from_unifier_type(unifier, primitives, *ty, cache),
-                },
                TypeEnum::TObj { obj_id, fields, params } => ConcreteTypeEnum::TObj {
                    obj_id: *obj_id,
                    fields: fields
@ -260,9 +254,6 @@ impl ConcreteTypeStore {
                    .map(|cty| self.to_unifier_type(unifier, primitives, *cty, cache))
                    .collect(),
            },
-            ConcreteTypeEnum::TList { ty } => {
-                TypeEnum::TList { ty: self.to_unifier_type(unifier, primitives, *ty, cache) }
-            }
            ConcreteTypeEnum::TVirtual { ty } => {
                TypeEnum::TVirtual { ty: self.to_unifier_type(unifier, primitives, *ty, cache) }
            }
--- a/nac3core/src/codegen/expr.rs
+++ b/nac3core/src/codegen/expr.rs
--- a/nac3core/src/codegen/extern_fns.rs
+++ b/nac3core/src/codegen/extern_fns.rs
@ -4,514 +4,97 @@ use itertools::Either;

 use crate::codegen::CodeGenContext;

-/// Invokes the [`tan`](https://en.cppreference.com/w/c/numeric/math/tan) function.
-pub fn call_tan<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    arg: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "tan";
+/// Macro to generate extern function
+/// Both function return type and function parameter type are `FloatValue`
+///
+/// Arguments:
+/// * `unary/binary`: Whether the extern function requires one (unary) or two (binary) operands
+/// * `$fn_name:ident`: The identifier of the rust function to be generated
+/// * `$extern_fn:literal`: Name of underlying extern function
+///
+/// Optional Arguments:
+/// * `$(,$attributes:literal)*)`: Attributes linked with the extern function
+/// The default attributes are "mustprogress", "nofree", "nounwind", "willreturn", and "writeonly"
+/// These will be used unless other attributes are specified
+/// * `$(,$args:ident)*`: Operands of the extern function
+/// The data type of these operands will be set to `FloatValue`
+///  
+macro_rules! generate_extern_fn {
+    ("unary", $fn_name:ident, $extern_fn:literal) => {
+        generate_extern_fn!($fn_name, $extern_fn, arg, "mustprogress", "nofree", "nounwind", "willreturn", "writeonly");
+    };
+    ("unary", $fn_name:ident, $extern_fn:literal $(,$attributes:literal)*) => {
+        generate_extern_fn!($fn_name, $extern_fn, arg $(,$attributes)*);
+    };
+    ("binary", $fn_name:ident, $extern_fn:literal) => {
+        generate_extern_fn!($fn_name, $extern_fn, arg1, arg2, "mustprogress", "nofree", "nounwind", "willreturn", "writeonly");
+    };
+    ("binary", $fn_name:ident, $extern_fn:literal $(,$attributes:literal)*) => {
+        generate_extern_fn!($fn_name, $extern_fn, arg1, arg2 $(,$attributes)*);
+    };
+    ($fn_name:ident, $extern_fn:literal $(,$args:ident)* $(,$attributes:literal)*) => {
+        #[doc = concat!("Invokes the [`", stringify!($extern_fn), "`](https://en.cppreference.com/w/c/numeric/math/", stringify!($llvm_name), ") function." )]
+        pub fn $fn_name<'ctx>(
+            ctx: &CodeGenContext<'ctx, '_>
+            $(,$args: FloatValue<'ctx>)*,
+            name: Option<&str>,
+        ) -> FloatValue<'ctx> {
+            const FN_NAME: &str = $extern_fn;

-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(arg.get_type(), llvm_f64);
+            let llvm_f64 = ctx.ctx.f64_type();
+            $(debug_assert_eq!($args.get_type(), llvm_f64);)*

-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        for attr in ["mustprogress", "nofree", "nounwind", "willreturn", "writeonly"] {
-            func.add_attribute(
-                AttributeLoc::Function,
-                ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id(attr), 0),
-            );
+            let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
+                let fn_type = llvm_f64.fn_type(&[$($args.get_type().into()),*], false);
+                let func = ctx.module.add_function(FN_NAME, fn_type, None);
+                for attr in [$($attributes),*] {
+                    func.add_attribute(
+                        AttributeLoc::Function,
+                        ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id(attr), 0),
+                    );
+                }
+                func
+            });
+
+            ctx.builder
+                .build_call(extern_fn, &[$($args.into()),*], name.unwrap_or_default())
+                .map(CallSiteValue::try_as_basic_value)
+                .map(|v| v.map_left(BasicValueEnum::into_float_value))
+                .map(Either::unwrap_left)
+                .unwrap()
        }
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[arg.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
+    };
 }

-/// Invokes the [`asin`](https://en.cppreference.com/w/c/numeric/math/asin) function.
-pub fn call_asin<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    arg: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "asin";
-
-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(arg.get_type(), llvm_f64);
-
-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        for attr in ["mustprogress", "nofree", "nounwind", "willreturn", "writeonly"] {
-            func.add_attribute(
-                AttributeLoc::Function,
-                ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id(attr), 0),
-            );
-        }
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[arg.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`acos`](https://en.cppreference.com/w/c/numeric/math/acos) function.
-pub fn call_acos<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    arg: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "acos";
-
-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(arg.get_type(), llvm_f64);
-
-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        for attr in ["mustprogress", "nofree", "nounwind", "willreturn", "writeonly"] {
-            func.add_attribute(
-                AttributeLoc::Function,
-                ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id(attr), 0),
-            );
-        }
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[arg.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`atan`](https://en.cppreference.com/w/c/numeric/math/atan) function.
-pub fn call_atan<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    arg: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "atan";
-
-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(arg.get_type(), llvm_f64);
-
-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        for attr in ["mustprogress", "nofree", "nounwind", "willreturn", "writeonly"] {
-            func.add_attribute(
-                AttributeLoc::Function,
-                ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id(attr), 0),
-            );
-        }
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[arg.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`sinh`](https://en.cppreference.com/w/c/numeric/math/sinh) function.
-pub fn call_sinh<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    arg: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "sinh";
-
-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(arg.get_type(), llvm_f64);
-
-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        for attr in ["mustprogress", "nofree", "nounwind", "willreturn", "writeonly"] {
-            func.add_attribute(
-                AttributeLoc::Function,
-                ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id(attr), 0),
-            );
-        }
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[arg.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`cosh`](https://en.cppreference.com/w/c/numeric/math/cosh) function.
-pub fn call_cosh<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    arg: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "cosh";
-
-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(arg.get_type(), llvm_f64);
-
-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        for attr in ["mustprogress", "nofree", "nounwind", "willreturn", "writeonly"] {
-            func.add_attribute(
-                AttributeLoc::Function,
-                ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id(attr), 0),
-            );
-        }
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[arg.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`tanh`](https://en.cppreference.com/w/c/numeric/math/tanh) function.
-pub fn call_tanh<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    arg: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "tanh";
-
-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(arg.get_type(), llvm_f64);
-
-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        for attr in ["mustprogress", "nofree", "nounwind", "willreturn", "writeonly"] {
-            func.add_attribute(
-                AttributeLoc::Function,
-                ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id(attr), 0),
-            );
-        }
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[arg.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`asinh`](https://en.cppreference.com/w/c/numeric/math/asinh) function.
-pub fn call_asinh<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    arg: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "asinh";
-
-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(arg.get_type(), llvm_f64);
-
-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        for attr in ["mustprogress", "nofree", "nounwind", "willreturn", "writeonly"] {
-            func.add_attribute(
-                AttributeLoc::Function,
-                ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id(attr), 0),
-            );
-        }
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[arg.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`acosh`](https://en.cppreference.com/w/c/numeric/math/acosh) function.
-pub fn call_acosh<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    arg: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "acosh";
-
-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(arg.get_type(), llvm_f64);
-
-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        for attr in ["mustprogress", "nofree", "nounwind", "willreturn", "writeonly"] {
-            func.add_attribute(
-                AttributeLoc::Function,
-                ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id(attr), 0),
-            );
-        }
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[arg.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`atanh`](https://en.cppreference.com/w/c/numeric/math/atanh) function.
-pub fn call_atanh<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    arg: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "atanh";
-
-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(arg.get_type(), llvm_f64);
-
-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        for attr in ["mustprogress", "nofree", "nounwind", "willreturn", "writeonly"] {
-            func.add_attribute(
-                AttributeLoc::Function,
-                ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id(attr), 0),
-            );
-        }
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[arg.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`expm1`](https://en.cppreference.com/w/c/numeric/math/expm1) function.
-pub fn call_expm1<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    arg: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "expm1";
-
-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(arg.get_type(), llvm_f64);
-
-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        for attr in ["mustprogress", "nofree", "nounwind", "willreturn", "writeonly"] {
-            func.add_attribute(
-                AttributeLoc::Function,
-                ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id(attr), 0),
-            );
-        }
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[arg.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`cbrt`](https://en.cppreference.com/w/c/numeric/math/cbrt) function.
-pub fn call_cbrt<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    arg: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "cbrt";
-
-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(arg.get_type(), llvm_f64);
-
-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        for attr in ["mustprogress", "nofree", "nosync", "nounwind", "readonly", "willreturn"] {
-            func.add_attribute(
-                AttributeLoc::Function,
-                ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id(attr), 0),
-            );
-        }
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[arg.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`erf`](https://en.cppreference.com/w/c/numeric/math/erf) function.
-pub fn call_erf<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    arg: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "erf";
-
-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(arg.get_type(), llvm_f64);
-
-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        func.add_attribute(
-            AttributeLoc::Function,
-            ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id("nounwind"), 0),
-        );
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[arg.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`erfc`](https://en.cppreference.com/w/c/numeric/math/erfc) function.
-pub fn call_erfc<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    arg: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "erfc";
-
-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(arg.get_type(), llvm_f64);
-
-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        func.add_attribute(
-            AttributeLoc::Function,
-            ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id("nounwind"), 0),
-        );
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[arg.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`j1`](https://www.gnu.org/software/libc/manual/html_node/Special-Functions.html#index-j1)
-/// function.
-pub fn call_j1<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    arg: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "j1";
-
-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(arg.get_type(), llvm_f64);
-
-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        func.add_attribute(
-            AttributeLoc::Function,
-            ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id("nounwind"), 0),
-        );
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[arg.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`atan2`](https://en.cppreference.com/w/c/numeric/math/atan2) function.
-pub fn call_atan2<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    y: FloatValue<'ctx>,
-    x: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "atan2";
-
-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(y.get_type(), llvm_f64);
-    debug_assert_eq!(x.get_type(), llvm_f64);
-
-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into(), llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        for attr in ["mustprogress", "nofree", "nounwind", "willreturn", "writeonly"] {
-            func.add_attribute(
-                AttributeLoc::Function,
-                ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id(attr), 0),
-            );
-        }
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[y.into(), x.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
+generate_extern_fn!("unary", call_tan, "tan");
+generate_extern_fn!("unary", call_asin, "asin");
+generate_extern_fn!("unary", call_acos, "acos");
+generate_extern_fn!("unary", call_atan, "atan");
+generate_extern_fn!("unary", call_sinh, "sinh");
+generate_extern_fn!("unary", call_cosh, "cosh");
+generate_extern_fn!("unary", call_tanh, "tanh");
+generate_extern_fn!("unary", call_asinh, "asinh");
+generate_extern_fn!("unary", call_acosh, "acosh");
+generate_extern_fn!("unary", call_atanh, "atanh");
+generate_extern_fn!("unary", call_expm1, "expm1");
+generate_extern_fn!(
+    "unary",
+    call_cbrt,
+    "cbrt",
+    "mustprogress",
+    "nofree",
+    "nosync",
+    "nounwind",
+    "readonly",
+    "willreturn"
+);
+generate_extern_fn!("unary", call_erf, "erf", "nounwind");
+generate_extern_fn!("unary", call_erfc, "erfc", "nounwind");
+generate_extern_fn!("unary", call_j1, "j1", "nounwind");
+
+generate_extern_fn!("binary", call_atan2, "atan2");
+generate_extern_fn!("binary", call_hypot, "hypot", "nounwind");
+generate_extern_fn!("binary", call_nextafter, "nextafter", "nounwind");

 /// Invokes the [`ldexp`](https://en.cppreference.com/w/c/numeric/math/ldexp) function.
 pub fn call_ldexp<'ctx>(
@ -547,67 +130,3 @@ pub fn call_ldexp<'ctx>(
        .map(Either::unwrap_left)
        .unwrap()
 }
-
-/// Invokes the [`hypot`](https://en.cppreference.com/w/c/numeric/math/hypot) function.
-pub fn call_hypot<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    x: FloatValue<'ctx>,
-    y: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "hypot";
-
-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(x.get_type(), llvm_f64);
-    debug_assert_eq!(y.get_type(), llvm_f64);
-
-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into(), llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        func.add_attribute(
-            AttributeLoc::Function,
-            ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id("nounwind"), 0),
-        );
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[x.into(), y.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`nextafter`](https://en.cppreference.com/w/c/numeric/math/nextafter) function.
-pub fn call_nextafter<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    from: FloatValue<'ctx>,
-    to: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "nextafter";
-
-    let llvm_f64 = ctx.ctx.f64_type();
-    debug_assert_eq!(from.get_type(), llvm_f64);
-    debug_assert_eq!(to.get_type(), llvm_f64);
-
-    let extern_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
-        let fn_type = llvm_f64.fn_type(&[llvm_f64.into(), llvm_f64.into()], false);
-        let func = ctx.module.add_function(FN_NAME, fn_type, None);
-        func.add_attribute(
-            AttributeLoc::Function,
-            ctx.ctx.create_enum_attribute(Attribute::get_named_enum_kind_id("nounwind"), 0),
-        );
-
-        func
-    });
-
-    ctx.builder
-        .build_call(extern_fn, &[from.into(), to.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
--- a/nac3core/src/codegen/irrt/irrt.c
+++ b/nac3core/src/codegen/irrt/irrt.c
@ -1,389 +0,0 @@
-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;
-
-# define MAX(a, b) (a > b ? a : b)
-# define MIN(a, b) (a > b ? b : a)
-
-# define NULL ((void *) 0)
-
-// 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
-#define DEF_INT_EXP(T) T __nac3_int_exp_##T( \
-    T base, \
-    T exp \
-) { \
-    T res = (T)1; \
-    /* repeated squaring method */ \
-    do { \
-       if (exp & 1) res *= base;  /* for n odd */ \
-       exp >>= 1; \
-       base *= base; \
-    } while (exp); \
-    return res; \
-} \
-
-DEF_INT_EXP(int32_t)
-DEF_INT_EXP(int64_t)
-DEF_INT_EXP(uint32_t)
-DEF_INT_EXP(uint64_t)
-
-
-int32_t __nac3_slice_index_bound(int32_t i, const int32_t len) {
-    if (i < 0) {
-        i = len + i;
-    }
-    if (i < 0) {
-        return 0;
-    } else if (i > len) {
-        return len;
-    }
-    return i;
-}
-
-int32_t __nac3_range_slice_len(const int32_t start, const int32_t end, const int32_t step) {
-    int32_t 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)
-int32_t __nac3_list_slice_assign_var_size(
-    int32_t dest_start,
-    int32_t dest_end,
-    int32_t dest_step,
-    uint8_t *dest_arr,
-    int32_t dest_arr_len,
-    int32_t src_start,
-    int32_t src_end,
-    int32_t src_step,
-    uint8_t *src_arr,
-    int32_t src_arr_len,
-    const int32_t 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 int32_t src_len = (src_end >= src_start) ? (src_end - src_start + 1) : 0;
-        const int32_t 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 = __builtin_alloca(src_arr_len * size);
-        __builtin_memcpy(tmp, src_arr, src_arr_len * size);
-        src_arr = tmp;
-    }
-    int32_t src_ind = src_start;
-    int32_t 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 uint64_t *list_data,
-    uint32_t list_len,
-    uint32_t begin_idx,
-    uint32_t end_idx
-) {
-    __builtin_assume(end_idx <= list_len);
-
-    uint32_t num_elems = 1;
-    for (uint32_t i = begin_idx; i < end_idx; ++i) {
-        uint64_t val = list_data[i];
-        __builtin_assume(val > 0);
-        num_elems *= val;
-    }
-    return num_elems;
-}
-
-uint64_t __nac3_ndarray_calc_size64(
-    const uint64_t *list_data,
-    uint64_t list_len,
-    uint64_t begin_idx,
-    uint64_t end_idx
-) {
-    __builtin_assume(end_idx <= list_len);
-
-    uint64_t num_elems = 1;
-    for (uint64_t i = begin_idx; i < end_idx; ++i) {
-        uint64_t val = list_data[i];
-        __builtin_assume(val > 0);
-       num_elems *= val;
-    }
-    return num_elems;
-}
-
-void __nac3_ndarray_calc_nd_indices(
-    uint32_t index,
-    const uint32_t* dims,
-    uint32_t num_dims,
-    uint32_t* idxs
-) {
-    uint32_t stride = 1;
-    for (uint32_t dim = 0; dim < num_dims; dim++) {
-        uint32_t i = num_dims - dim - 1;
-        __builtin_assume(dims[i] > 0);
-        idxs[i] = (index / stride) % dims[i];
-        stride *= dims[i];
-    }
-}
-
-void __nac3_ndarray_calc_nd_indices64(
-    uint64_t index,
-    const uint64_t* dims,
-    uint64_t num_dims,
-    uint32_t* idxs
-) {
-    uint64_t stride = 1;
-    for (uint64_t dim = 0; dim < num_dims; dim++) {
-        uint64_t i = num_dims - dim - 1;
-        __builtin_assume(dims[i] > 0);
-        idxs[i] = (uint32_t) ((index / stride) % dims[i]);
-        stride *= dims[i];
-    }
-}
-
-uint32_t __nac3_ndarray_flatten_index(
-    const uint32_t* dims,
-    uint32_t num_dims,
-    const uint32_t* indices,
-    uint32_t num_indices
-) {
-    uint32_t idx = 0;
-    uint32_t stride = 1;
-    for (uint32_t i = 0; i < num_dims; ++i) {
-        uint32_t ri = num_dims - i - 1;
-        if (ri < num_indices) {
-            idx += (stride * indices[ri]);
-        }
-
-        __builtin_assume(dims[i] > 0);
-        stride *= dims[ri];
-    }
-    return idx;
-}
-
-uint64_t __nac3_ndarray_flatten_index64(
-    const uint64_t* dims,
-    uint64_t num_dims,
-    const uint32_t* indices,
-    uint64_t num_indices
-) {
-    uint64_t idx = 0;
-    uint64_t stride = 1;
-    for (uint64_t i = 0; i < num_dims; ++i) {
-        uint64_t ri = num_dims - i - 1;
-        if (ri < num_indices) {
-            idx += (stride * indices[ri]);
-        }
-
-        __builtin_assume(dims[i] > 0);
-        stride *= dims[ri];
-    }
-    return idx;
-}
-
-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
-) {
-    uint32_t max_ndims = lhs_ndims > rhs_ndims ? lhs_ndims : rhs_ndims;
-
-    for (uint32_t i = 0; i < max_ndims; ++i) {
-        uint32_t *lhs_dim_sz = i < lhs_ndims ? &lhs_dims[lhs_ndims - i - 1] : NULL;
-        uint32_t *rhs_dim_sz = i < rhs_ndims ? &rhs_dims[rhs_ndims - i - 1] : NULL;
-        uint32_t *out_dim = &out_dims[max_ndims - i - 1];
-
-        if (lhs_dim_sz == NULL) {
-            *out_dim = *rhs_dim_sz;
-        } else if (rhs_dim_sz == NULL) {
-            *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();
-        }
-    }
-}
-
-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
-) {
-    uint64_t max_ndims = lhs_ndims > rhs_ndims ? lhs_ndims : rhs_ndims;
-
-    for (uint64_t i = 0; i < max_ndims; ++i) {
-        uint64_t *lhs_dim_sz = i < lhs_ndims ? &lhs_dims[lhs_ndims - i - 1] : NULL;
-        uint64_t *rhs_dim_sz = i < rhs_ndims ? &rhs_dims[rhs_ndims - i - 1] : NULL;
-        uint64_t *out_dim = &out_dims[max_ndims - i - 1];
-
-        if (lhs_dim_sz == NULL) {
-            *out_dim = *rhs_dim_sz;
-        } else if (rhs_dim_sz == NULL) {
-            *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();
-        }
-    }
-}
-
-void __nac3_ndarray_calc_broadcast_idx(
-    const uint32_t *src_dims,
-    uint32_t src_ndims,
-    const uint32_t *in_idx,
-    uint32_t *out_idx
-) {
-    for (uint32_t i = 0; i < src_ndims; ++i) {
-        uint32_t src_i = src_ndims - i - 1;
-        out_idx[src_i] = src_dims[src_i] == 1 ? 0 : in_idx[src_i];
-    }
-}
-
-void __nac3_ndarray_calc_broadcast_idx64(
-    const uint64_t *src_dims,
-    uint64_t src_ndims,
-    const uint32_t *in_idx,
-    uint32_t *out_idx
-) {
-    for (uint64_t i = 0; i < src_ndims; ++i) {
-        uint64_t src_i = src_ndims - i - 1;
-        out_idx[src_i] = src_dims[src_i] == 1 ? 0 : (uint32_t) in_idx[src_i];
-    }
-}
--- a/nac3core/src/codegen/irrt/mod.rs
+++ b/nac3core/src/codegen/irrt/mod.rs
@ -1,9 +1,11 @@
-use crate::typecheck::typedef::Type;
+use crate::{typecheck::typedef::Type, util::SizeVariant};
+
+mod test;

 use super::{
    classes::{
-        ArrayLikeIndexer, ArrayLikeValue, ArraySliceValue, ListValue, NDArrayValue,
-        TypedArrayLikeAdapter, UntypedArrayLikeAccessor,
+        ArrayLikeIndexer, ArrayLikeValue, ArraySliceValue, ListValue, NDArrayValue, NpArrayType,
+        NpArrayValue, TypedArrayLikeAdapter, UntypedArrayLikeAccessor,
    },
    llvm_intrinsics, CodeGenContext, CodeGenerator,
 };
@ -14,8 +16,8 @@ use inkwell::{
    context::Context,
    memory_buffer::MemoryBuffer,
    module::Module,
-    types::{BasicTypeEnum, IntType},
-    values::{BasicValueEnum, CallSiteValue, FloatValue, IntValue},
+    types::{BasicType, BasicTypeEnum, FunctionType, IntType, PointerType},
+    values::{BasicValueEnum, CallSiteValue, FloatValue, FunctionValue, IntValue},
    AddressSpace, IntPredicate,
 };
 use itertools::Either;
@ -579,10 +581,8 @@ where
    G: CodeGenerator + ?Sized,
    Dims: ArrayLikeIndexer<'ctx>,
 {
-    let llvm_i64 = ctx.ctx.i64_type();
    let llvm_usize = generator.get_size_type(ctx.ctx);
-
-    let llvm_pi64 = llvm_i64.ptr_type(AddressSpace::default());
+    let llvm_pusize = llvm_usize.ptr_type(AddressSpace::default());

    let ndarray_calc_size_fn_name = match llvm_usize.get_bit_width() {
        32 => "__nac3_ndarray_calc_size",
@ -590,7 +590,7 @@ where
        bw => unreachable!("Unsupported size type bit width: {}", bw),
    };
    let ndarray_calc_size_fn_t = llvm_usize.fn_type(
-        &[llvm_pi64.into(), llvm_usize.into(), llvm_usize.into(), llvm_usize.into()],
+        &[llvm_pusize.into(), llvm_usize.into(), llvm_usize.into(), llvm_usize.into()],
        false,
    );
    let ndarray_calc_size_fn =
@ -929,3 +929,63 @@ 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/test.rs
+++ b/nac3core/src/codegen/irrt/test.rs
@ -0,0 +1,26 @@
+#[cfg(test)]
+mod tests {
+    use std::{path::Path, process::Command};
+
+    #[test]
+    fn run_irrt_test() {
+        assert!(
+            cfg!(feature = "test"),
+            "Please do `cargo test -F test` to compile `irrt_test.out` and run test"
+        );
+
+        let irrt_test_out_path = Path::new(concat!(env!("OUT_DIR"), "/irrt_test.out"));
+        let output = Command::new(irrt_test_out_path.to_str().unwrap()).output().unwrap();
+
+        if !output.status.success() {
+            eprintln!("irrt_test failed with status {}:", output.status);
+            eprintln!("====== stdout ======");
+            eprintln!("{}", String::from_utf8(output.stdout).unwrap());
+            eprintln!("====== stderr ======");
+            eprintln!("{}", String::from_utf8(output.stderr).unwrap());
+            eprintln!("====================");
+
+            panic!("irrt_test failed");
+        }
+    }
+}
--- a/nac3core/src/codegen/llvm_intrinsics.rs
+++ b/nac3core/src/codegen/llvm_intrinsics.rs
@ -62,145 +62,30 @@ pub fn call_stacksave<'ctx>(
 pub fn call_stackrestore<'ctx>(ctx: &CodeGenContext<'ctx, '_>, ptr: PointerValue<'ctx>) {
    const FN_NAME: &str = "llvm.stackrestore";

-    let llvm_i8 = ctx.ctx.i8_type();
-    let llvm_p0i8 = llvm_i8.ptr_type(AddressSpace::default());
+    /*
+        SEE https://github.com/TheDan64/inkwell/issues/496

-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_p0i8.into()]))
-        .unwrap();
+        We want `llvm.stackrestore`, but the following would generate `llvm.stackrestore.p0i8`.
+        ```ignore
+        let intrinsic_fn = Intrinsic::find(FN_NAME)
+            .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_p0i8.into()]))
+            .unwrap();
+        ```
+
+        Temp workaround by manually declaring the intrinsic with the correct function name instead.
+    */
+    let intrinsic_fn = ctx.module.get_function(FN_NAME).unwrap_or_else(|| {
+        let llvm_void = ctx.ctx.void_type();
+        let llvm_i8 = ctx.ctx.i8_type();
+        let llvm_p0i8 = llvm_i8.ptr_type(AddressSpace::default());
+        let fn_type = llvm_void.fn_type(&[llvm_p0i8.into()], false);
+
+        ctx.module.add_function(FN_NAME, fn_type, None)
+    });

    ctx.builder.build_call(intrinsic_fn, &[ptr.into()], "").unwrap();
 }

-/// Invokes the [`llvm.abs`](https://llvm.org/docs/LangRef.html#llvm-abs-intrinsic) intrinsic.
-///
-/// * `src` - The value for which the absolute value is to be returned.
-/// * `is_int_min_poison` - Whether `poison` is to be returned if `src` is `INT_MIN`.
-pub fn call_int_abs<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    src: IntValue<'ctx>,
-    is_int_min_poison: IntValue<'ctx>,
-    name: Option<&str>,
-) -> IntValue<'ctx> {
-    const FN_NAME: &str = "llvm.abs";
-
-    debug_assert_eq!(is_int_min_poison.get_type().get_bit_width(), 1);
-    debug_assert!(is_int_min_poison.is_const());
-
-    let llvm_src_t = src.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_src_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[src.into(), is_int_min_poison.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_int_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.smax`](https://llvm.org/docs/LangRef.html#llvm-smax-intrinsic) intrinsic.
-pub fn call_int_smax<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    a: IntValue<'ctx>,
-    b: IntValue<'ctx>,
-    name: Option<&str>,
-) -> IntValue<'ctx> {
-    const FN_NAME: &str = "llvm.smax";
-
-    debug_assert_eq!(a.get_type().get_bit_width(), b.get_type().get_bit_width());
-
-    let llvm_int_t = a.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_int_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[a.into(), b.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_int_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.smin`](https://llvm.org/docs/LangRef.html#llvm-smin-intrinsic) intrinsic.
-pub fn call_int_smin<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    a: IntValue<'ctx>,
-    b: IntValue<'ctx>,
-    name: Option<&str>,
-) -> IntValue<'ctx> {
-    const FN_NAME: &str = "llvm.smin";
-
-    debug_assert_eq!(a.get_type().get_bit_width(), b.get_type().get_bit_width());
-
-    let llvm_int_t = a.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_int_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[a.into(), b.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_int_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.umax`](https://llvm.org/docs/LangRef.html#llvm-umax-intrinsic) intrinsic.
-pub fn call_int_umax<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    a: IntValue<'ctx>,
-    b: IntValue<'ctx>,
-    name: Option<&str>,
-) -> IntValue<'ctx> {
-    const FN_NAME: &str = "llvm.umax";
-
-    debug_assert_eq!(a.get_type().get_bit_width(), b.get_type().get_bit_width());
-
-    let llvm_int_t = a.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_int_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[a.into(), b.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_int_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.umin`](https://llvm.org/docs/LangRef.html#llvm-umin-intrinsic) intrinsic.
-pub fn call_int_umin<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    a: IntValue<'ctx>,
-    b: IntValue<'ctx>,
-    name: Option<&str>,
-) -> IntValue<'ctx> {
-    const FN_NAME: &str = "llvm.umin";
-
-    debug_assert_eq!(a.get_type().get_bit_width(), b.get_type().get_bit_width());
-
-    let llvm_int_t = a.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_int_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[a.into(), b.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_int_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
 /// Invokes the [`llvm.memcpy`](https://llvm.org/docs/LangRef.html#llvm-memcpy-intrinsic) intrinsic.
 ///
 /// * `dest` - The pointer to the destination. Must be a pointer to an integer type.
@ -280,28 +165,122 @@ pub fn call_memcpy_generic<'ctx>(
    call_memcpy(ctx, dest, src, len, is_volatile);
 }

-/// Invokes the [`llvm.sqrt`](https://llvm.org/docs/LangRef.html#llvm-sqrt-intrinsic) intrinsic.
-pub fn call_float_sqrt<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    val: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "llvm.sqrt";
-
-    let llvm_float_t = val.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_float_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[val.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
+/// Macro to find and generate build call for llvm intrinsic (body of llvm intrinsic function)
+///
+/// Arguments:
+/// * `$ctx:ident`: Reference to the current Code Generation Context
+/// * `$name:ident`: Optional name to be assigned to the llvm build call (Option<&str>)
+/// * `$llvm_name:literal`: Name of underlying llvm intrinsic function
+/// * `$map_fn:ident`: Mapping function to be applied on `BasicValue` (`BasicValue` -> Function Return Type)
+/// Use `BasicValueEnum::into_int_value` for Integer return type and `BasicValueEnum::into_float_value` for Float return type
+/// * `$llvm_ty:ident`: Type of first operand
+/// * `,($val:ident)*`: Comma separated list of operands
+macro_rules! generate_llvm_intrinsic_fn_body {
+    ($ctx:ident, $name:ident, $llvm_name:literal, $map_fn:expr, $llvm_ty:ident $(,$val:ident)*) => {{
+        const FN_NAME: &str = concat!("llvm.", $llvm_name);
+        let intrinsic_fn = Intrinsic::find(FN_NAME).and_then(|intrinsic| intrinsic.get_declaration(&$ctx.module, &[$llvm_ty.into()])).unwrap();
+        $ctx.builder.build_call(intrinsic_fn, &[$($val.into()),*],  $name.unwrap_or_default()).map(CallSiteValue::try_as_basic_value).map(|v| v.map_left($map_fn)).map(Either::unwrap_left).unwrap()
+    }};
 }

+/// Macro to generate the llvm intrinsic function using [`generate_llvm_intrinsic_fn_body`].
+///
+/// Arguments:
+/// * `float/int`: Indicates the return and argument type of the function
+/// * `$fn_name:ident`: The identifier of the rust function to be generated
+/// * `$llvm_name:literal`: Name of underlying llvm intrinsic function
+/// Omit "llvm." prefix from the function name i.e. use "ceil" instead of "llvm.ceil"
+/// * `$val:ident`: The operand for unary operations
+/// * `$val1:ident`, `$val2:ident`: The operands for binary operations
+macro_rules! generate_llvm_intrinsic_fn {
+    ("float", $fn_name:ident, $llvm_name:literal, $val:ident) => {
+        #[doc = concat!("Invokes the [`", stringify!($llvm_name), "`](https://llvm.org/docs/LangRef.html#llvm-", stringify!($llvm_name), "-intrinsic) intrinsic." )]
+        pub fn $fn_name<'ctx> (
+            ctx: &CodeGenContext<'ctx, '_>,
+            $val: FloatValue<'ctx>,
+            name: Option<&str>,
+        ) -> FloatValue<'ctx> {
+            let llvm_ty = $val.get_type();
+            generate_llvm_intrinsic_fn_body!(ctx, name, $llvm_name, BasicValueEnum::into_float_value, llvm_ty, $val)
+        }
+    };
+    ("float", $fn_name:ident, $llvm_name:literal, $val1:ident, $val2:ident) => {
+        #[doc = concat!("Invokes the [`", stringify!($llvm_name), "`](https://llvm.org/docs/LangRef.html#llvm-", stringify!($llvm_name), "-intrinsic) intrinsic." )]
+        pub fn $fn_name<'ctx> (
+            ctx: &CodeGenContext<'ctx, '_>,
+            $val1: FloatValue<'ctx>,
+            $val2: FloatValue<'ctx>,
+            name: Option<&str>,
+        ) -> FloatValue<'ctx> {
+            debug_assert_eq!($val1.get_type(), $val2.get_type());
+            let llvm_ty = $val1.get_type();
+            generate_llvm_intrinsic_fn_body!(ctx, name, $llvm_name, BasicValueEnum::into_float_value, llvm_ty, $val1, $val2)
+        }
+    };
+    ("int", $fn_name:ident, $llvm_name:literal, $val1:ident, $val2:ident) => {
+        #[doc = concat!("Invokes the [`", stringify!($llvm_name), "`](https://llvm.org/docs/LangRef.html#llvm-", stringify!($llvm_name), "-intrinsic) intrinsic." )]
+        pub fn $fn_name<'ctx> (
+            ctx: &CodeGenContext<'ctx, '_>,
+            $val1: IntValue<'ctx>,
+            $val2: IntValue<'ctx>,
+            name: Option<&str>,
+        ) -> IntValue<'ctx> {
+            debug_assert_eq!($val1.get_type().get_bit_width(), $val2.get_type().get_bit_width());
+            let llvm_ty = $val1.get_type();
+            generate_llvm_intrinsic_fn_body!(ctx, name, $llvm_name, BasicValueEnum::into_int_value, llvm_ty, $val1, $val2)
+        }
+    };
+}
+
+/// Invokes the [`llvm.abs`](https://llvm.org/docs/LangRef.html#llvm-abs-intrinsic) intrinsic.
+///
+/// * `src` - The value for which the absolute value is to be returned.
+/// * `is_int_min_poison` - Whether `poison` is to be returned if `src` is `INT_MIN`.
+pub fn call_int_abs<'ctx>(
+    ctx: &CodeGenContext<'ctx, '_>,
+    src: IntValue<'ctx>,
+    is_int_min_poison: IntValue<'ctx>,
+    name: Option<&str>,
+) -> IntValue<'ctx> {
+    debug_assert_eq!(is_int_min_poison.get_type().get_bit_width(), 1);
+    debug_assert!(is_int_min_poison.is_const());
+
+    let src_type = src.get_type();
+    generate_llvm_intrinsic_fn_body!(
+        ctx,
+        name,
+        "abs",
+        BasicValueEnum::into_int_value,
+        src_type,
+        src,
+        is_int_min_poison
+    )
+}
+
+generate_llvm_intrinsic_fn!("int", call_int_smax, "smax", a, b);
+generate_llvm_intrinsic_fn!("int", call_int_smin, "smin", a, b);
+generate_llvm_intrinsic_fn!("int", call_int_umax, "umax", a, b);
+generate_llvm_intrinsic_fn!("int", call_int_umin, "umin", a, b);
+generate_llvm_intrinsic_fn!("int", call_expect, "expect", val, expected_val);
+
+generate_llvm_intrinsic_fn!("float", call_float_sqrt, "sqrt", val);
+generate_llvm_intrinsic_fn!("float", call_float_sin, "sin", val);
+generate_llvm_intrinsic_fn!("float", call_float_cos, "cos", val);
+generate_llvm_intrinsic_fn!("float", call_float_pow, "pow", val, power);
+generate_llvm_intrinsic_fn!("float", call_float_exp, "exp", val);
+generate_llvm_intrinsic_fn!("float", call_float_exp2, "exp2", val);
+generate_llvm_intrinsic_fn!("float", call_float_log, "log", val);
+generate_llvm_intrinsic_fn!("float", call_float_log10, "log10", val);
+generate_llvm_intrinsic_fn!("float", call_float_log2, "log2", val);
+generate_llvm_intrinsic_fn!("float", call_float_fabs, "fabs", src);
+generate_llvm_intrinsic_fn!("float", call_float_minnum, "minnum", val, power);
+generate_llvm_intrinsic_fn!("float", call_float_maxnum, "maxnum", val, power);
+generate_llvm_intrinsic_fn!("float", call_float_copysign, "copysign", mag, sgn);
+generate_llvm_intrinsic_fn!("float", call_float_floor, "floor", val);
+generate_llvm_intrinsic_fn!("float", call_float_ceil, "ceil", val);
+generate_llvm_intrinsic_fn!("float", call_float_round, "round", val);
+generate_llvm_intrinsic_fn!("float", call_float_rint, "rint", val);
+
 /// Invokes the [`llvm.powi`](https://llvm.org/docs/LangRef.html#llvm-powi-intrinsic) intrinsic.
 pub fn call_float_powi<'ctx>(
    ctx: &CodeGenContext<'ctx, '_>,
@ -327,393 +306,3 @@ pub fn call_float_powi<'ctx>(
        .map(Either::unwrap_left)
        .unwrap()
 }
-
-/// Invokes the [`llvm.sin`](https://llvm.org/docs/LangRef.html#llvm-sin-intrinsic) intrinsic.
-pub fn call_float_sin<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    val: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "llvm.sin";
-
-    let llvm_float_t = val.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_float_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[val.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.cos`](https://llvm.org/docs/LangRef.html#llvm-cos-intrinsic) intrinsic.
-pub fn call_float_cos<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    val: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "llvm.cos";
-
-    let llvm_float_t = val.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_float_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[val.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.pow`](https://llvm.org/docs/LangRef.html#llvm-pow-intrinsic) intrinsic.
-pub fn call_float_pow<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    val: FloatValue<'ctx>,
-    power: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "llvm.pow";
-
-    debug_assert_eq!(val.get_type(), power.get_type());
-
-    let llvm_float_t = val.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_float_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[val.into(), power.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.exp`](https://llvm.org/docs/LangRef.html#llvm-exp-intrinsic) intrinsic.
-pub fn call_float_exp<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    val: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "llvm.exp";
-
-    let llvm_float_t = val.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_float_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[val.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.exp2`](https://llvm.org/docs/LangRef.html#llvm-exp2-intrinsic) intrinsic.
-pub fn call_float_exp2<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    val: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "llvm.exp2";
-
-    let llvm_float_t = val.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_float_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[val.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.log`](https://llvm.org/docs/LangRef.html#llvm-log-intrinsic) intrinsic.
-pub fn call_float_log<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    val: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "llvm.log";
-
-    let llvm_float_t = val.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_float_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[val.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.log10`](https://llvm.org/docs/LangRef.html#llvm-log10-intrinsic) intrinsic.
-pub fn call_float_log10<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    val: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "llvm.log10";
-
-    let llvm_float_t = val.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_float_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[val.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.log2`](https://llvm.org/docs/LangRef.html#llvm-log2-intrinsic) intrinsic.
-pub fn call_float_log2<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    val: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "llvm.log2";
-
-    let llvm_float_t = val.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_float_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[val.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.fabs`](https://llvm.org/docs/LangRef.html#llvm-fabs-intrinsic) intrinsic.
-pub fn call_float_fabs<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    src: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "llvm.fabs";
-
-    let llvm_src_t = src.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_src_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[src.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.minnum`](https://llvm.org/docs/LangRef.html#llvm-minnum-intrinsic) intrinsic.
-pub fn call_float_minnum<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    val1: FloatValue<'ctx>,
-    val2: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "llvm.minnum";
-
-    debug_assert_eq!(val1.get_type(), val2.get_type());
-
-    let llvm_float_t = val1.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_float_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[val1.into(), val2.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.maxnum`](https://llvm.org/docs/LangRef.html#llvm-maxnum-intrinsic) intrinsic.
-pub fn call_float_maxnum<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    val1: FloatValue<'ctx>,
-    val2: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "llvm.maxnum";
-
-    debug_assert_eq!(val1.get_type(), val2.get_type());
-
-    let llvm_float_t = val1.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_float_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[val1.into(), val2.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.copysign`](https://llvm.org/docs/LangRef.html#llvm-copysign-intrinsic) intrinsic.
-pub fn call_float_copysign<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    mag: FloatValue<'ctx>,
-    sgn: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "llvm.copysign";
-
-    debug_assert_eq!(mag.get_type(), sgn.get_type());
-
-    let llvm_float_t = mag.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_float_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[mag.into(), sgn.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.floor`](https://llvm.org/docs/LangRef.html#llvm-floor-intrinsic) intrinsic.
-pub fn call_float_floor<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    val: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "llvm.floor";
-
-    let llvm_float_t = val.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_float_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[val.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.ceil`](https://llvm.org/docs/LangRef.html#llvm-ceil-intrinsic) intrinsic.
-pub fn call_float_ceil<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    val: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "llvm.ceil";
-
-    let llvm_float_t = val.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_float_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[val.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.round`](https://llvm.org/docs/LangRef.html#llvm-round-intrinsic) intrinsic.
-pub fn call_float_round<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    val: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "llvm.round";
-
-    let llvm_float_t = val.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_float_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[val.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the
-/// [`llvm.roundeven`](https://llvm.org/docs/LangRef.html#llvm-roundeven-intrinsic) intrinsic.
-pub fn call_float_roundeven<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    val: FloatValue<'ctx>,
-    name: Option<&str>,
-) -> FloatValue<'ctx> {
-    const FN_NAME: &str = "llvm.roundeven";
-
-    let llvm_float_t = val.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_float_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[val.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_float_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
-
-/// Invokes the [`llvm.expect`](https://llvm.org/docs/LangRef.html#llvm-expect-intrinsic) intrinsic.
-pub fn call_expect<'ctx>(
-    ctx: &CodeGenContext<'ctx, '_>,
-    val: IntValue<'ctx>,
-    expected_val: IntValue<'ctx>,
-    name: Option<&str>,
-) -> IntValue<'ctx> {
-    const FN_NAME: &str = "llvm.expect";
-
-    debug_assert_eq!(val.get_type().get_bit_width(), expected_val.get_type().get_bit_width());
-
-    let llvm_int_t = val.get_type();
-
-    let intrinsic_fn = Intrinsic::find(FN_NAME)
-        .and_then(|intrinsic| intrinsic.get_declaration(&ctx.module, &[llvm_int_t.into()]))
-        .unwrap();
-
-    ctx.builder
-        .build_call(intrinsic_fn, &[val.into(), expected_val.into()], name.unwrap_or_default())
-        .map(CallSiteValue::try_as_basic_value)
-        .map(|v| v.map_left(BasicValueEnum::into_int_value))
-        .map(Either::unwrap_left)
-        .unwrap()
-}
--- a/nac3core/src/codegen/mod.rs
+++ b/nac3core/src/codegen/mod.rs
@ -456,6 +456,20 @@ fn get_llvm_type<'ctx, G: CodeGenerator + ?Sized>(
                            .into()
                        }

+                        TObj { obj_id, params, .. } if *obj_id == PrimDef::List.id() => {
+                            let element_type = get_llvm_type(
+                                ctx,
+                                module,
+                                generator,
+                                unifier,
+                                top_level,
+                                type_cache,
+                                *params.iter().next().unwrap().1,
+                            );
+
+                            ListType::new(generator, ctx, element_type).as_base_type().into()
+                        }
+
                        TObj { obj_id, .. } if *obj_id == PrimDef::NDArray.id() => {
                            let (dtype, _) = unpack_ndarray_var_tys(unifier, ty);
                            let element_type = get_llvm_type(
@ -516,12 +530,6 @@ fn get_llvm_type<'ctx, G: CodeGenerator + ?Sized>(
                    .collect_vec();
                ctx.struct_type(&fields, false).into()
            }
-            TList { ty } => {
-                let element_type =
-                    get_llvm_type(ctx, module, generator, unifier, top_level, type_cache, *ty);
-
-                ListType::new(generator, ctx, element_type).as_base_type().into()
-            }
            TVirtual { .. } => unimplemented!(),
            _ => unreachable!("{}", ty_enum.get_type_name()),
        };
--- a/nac3core/src/codegen/numpy.rs
+++ b/nac3core/src/codegen/numpy.rs
--- a/nac3core/src/codegen/stmt.rs
+++ b/nac3core/src/codegen/stmt.rs
@ -11,7 +11,10 @@ use crate::{
        gen_in_range_check,
    },
    toplevel::{helper::PrimDef, numpy::unpack_ndarray_var_tys, DefinitionId, TopLevelDef},
-    typecheck::typedef::{FunSignature, Type, TypeEnum},
+    typecheck::{
+        magic_methods::Binop,
+        typedef::{FunSignature, Type, TypeEnum},
+    },
 };
 use inkwell::{
    attributes::{Attribute, AttributeLoc},
@ -113,7 +116,7 @@ pub fn gen_store_target<'ctx, G: CodeGenerator>(
            }
        },
        ExprKind::Attribute { value, attr, .. } => {
-            let index = ctx.get_attr_index(value.custom.unwrap(), *attr);
+            let (index, _) = ctx.get_attr_index(value.custom.unwrap(), *attr);
            let val = if let Some(v) = generator.gen_expr(ctx, value)? {
                v.to_basic_value_enum(ctx, generator, value.custom.unwrap())?
            } else {
@ -136,7 +139,7 @@ pub fn gen_store_target<'ctx, G: CodeGenerator>(
        }
        ExprKind::Subscript { value, slice, .. } => {
            match ctx.unifier.get_ty_immutable(value.custom.unwrap()).as_ref() {
-                TypeEnum::TList { .. } => {
+                TypeEnum::TObj { obj_id, .. } if *obj_id == PrimDef::List.id() => {
                    let v = generator
                        .gen_expr(ctx, value)?
                        .unwrap()
@ -243,7 +246,9 @@ pub fn gen_assign<'ctx, G: CodeGenerator>(
                .into_pointer_value();
            let value = ListValue::from_ptr_val(value, llvm_usize, None);
            let ty = match &*ctx.unifier.get_ty_immutable(target.custom.unwrap()) {
-                TypeEnum::TList { ty } => *ty,
+                TypeEnum::TObj { obj_id, params, .. } if *obj_id == PrimDef::List.id() => {
+                    *params.iter().next().unwrap().1
+                }
                TypeEnum::TObj { obj_id, .. } if *obj_id == PrimDef::NDArray.id() => {
                    unpack_ndarray_var_tys(&mut ctx.unifier, target.custom.unwrap()).0
                }
@ -462,12 +467,14 @@ pub fn gen_for<G: CodeGenerator>(
    Ok(())
 }

-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(PartialEq, Eq, Debug, Clone, Copy, Hash)]
 pub struct BreakContinueHooks<'ctx> {
-    /// [`BasicBlock`] to branch to for `break`-ing out of the loop.
-    pub break_bb: BasicBlock<'ctx>,
-    /// [`BasicBlock`] to branch to for `continue`-ing to the next iteration in the loop.
-    pub continue_bb: BasicBlock<'ctx>,
+    /// The [exit block][`BasicBlock`] to branch to when `break`-ing out of a loop.
+    pub exit_bb: BasicBlock<'ctx>,
+
+    /// The [latch basic block][`BasicBlock`] to branch to for `continue`-ing to the next iteration
+    /// of the loop.
+    pub latch_bb: BasicBlock<'ctx>,
 }

 /// Generates a C-style `for` construct using lambdas, similar to the following C code:
@ -529,7 +536,7 @@ where
    }

    ctx.builder.position_at_end(body_bb);
-    let hooks = BreakContinueHooks { break_bb: cont_bb, continue_bb: update_bb };
+    let hooks = BreakContinueHooks { exit_bb: cont_bb, latch_bb: update_bb };
    body(generator, ctx, hooks, loop_var.clone())?;
    if !ctx.is_terminated() {
        ctx.builder.build_unconditional_branch(update_bb).unwrap();
@ -1589,7 +1596,14 @@ 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 = gen_binop_expr(generator, ctx, target, *op, value, stmt.location, true)?;
+            let value = gen_binop_expr(
+                generator,
+                ctx,
+                target,
+                Binop::aug_assign(*op),
+                value,
+                stmt.location,
+            )?;
            generator.gen_assign(ctx, target, value.unwrap())?;
        }
        StmtKind::Try { .. } => gen_try(generator, ctx, stmt)?,
--- a/nac3core/src/lib.rs
+++ b/nac3core/src/lib.rs
@ -23,3 +23,4 @@ pub mod codegen;
 pub mod symbol_resolver;
 pub mod toplevel;
 pub mod typecheck;
+pub mod util;
--- a/nac3core/src/symbol_resolver.rs
+++ b/nac3core/src/symbol_resolver.rs
@ -382,13 +382,12 @@ pub trait SymbolResolver {
 }

 thread_local! {
-    static IDENTIFIER_ID: [StrRef; 12] = [
+    static IDENTIFIER_ID: [StrRef; 11] = [
        "int32".into(),
        "int64".into(),
        "float".into(),
        "bool".into(),
        "virtual".into(),
-        "list".into(),
        "tuple".into(),
        "str".into(),
        "Exception".into(),
@ -413,13 +412,12 @@ pub fn parse_type_annotation<T>(
    let float_id = ids[2];
    let bool_id = ids[3];
    let virtual_id = ids[4];
-    let list_id = ids[5];
-    let tuple_id = ids[6];
-    let str_id = ids[7];
-    let exn_id = ids[8];
-    let uint32_id = ids[9];
-    let uint64_id = ids[10];
-    let literal_id = ids[11];
+    let tuple_id = ids[5];
+    let str_id = ids[6];
+    let exn_id = ids[7];
+    let uint32_id = ids[8];
+    let uint64_id = ids[9];
+    let literal_id = ids[10];

    let name_handling = |id: &StrRef, loc: Location, unifier: &mut Unifier| {
        if *id == int32_id {
@ -476,9 +474,6 @@ pub fn parse_type_annotation<T>(
        if *id == virtual_id {
            let ty = parse_type_annotation(resolver, top_level_defs, unifier, primitives, slice)?;
            Ok(unifier.add_ty(TypeEnum::TVirtual { ty }))
-        } else if *id == list_id {
-            let ty = parse_type_annotation(resolver, top_level_defs, unifier, primitives, slice)?;
-            Ok(unifier.add_ty(TypeEnum::TList { ty }))
        } else if *id == tuple_id {
            if let Tuple { elts, .. } = &slice.node {
                let ty = elts
--- a/nac3core/src/toplevel/builtins.rs
+++ b/nac3core/src/toplevel/builtins.rs
@ -1,5 +1,6 @@
 use std::iter::once;

+use crate::util::SizeVariant;
 use helper::{debug_assert_prim_is_allowed, make_exception_fields, PrimDefDetails};
 use indexmap::IndexMap;
 use inkwell::{
@ -14,10 +15,7 @@ use strum::IntoEnumIterator;
 use crate::{
    codegen::{
        builtin_fns,
-        classes::{
-            ArrayLikeValue, NDArrayValue, ProxyType, ProxyValue, RangeType, RangeValue,
-            TypedArrayLikeAccessor,
-        },
+        classes::{ArrayLikeValue, NDArrayValue, ProxyValue, RangeValue, TypedArrayLikeAccessor},
        expr::destructure_range,
        irrt::*,
        numpy::*,
@ -83,6 +81,7 @@ pub fn get_exn_constructor(
        object_id: DefinitionId(class_id),
        type_vars: Vec::default(),
        fields: exception_fields,
+        attributes: Vec::default(),
        methods: vec![("__init__".into(), signature, DefinitionId(cons_id))],
        ancestors: vec![
            TypeAnnotation::CustomClass { id: DefinitionId(class_id), params: Vec::default() },
@ -280,19 +279,10 @@ pub fn get_builtins(unifier: &mut Unifier, primitives: &PrimitiveStore) -> Built
        .collect()
 }

-/// 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,
-        }
+fn size_variant_to_int_type(variant: SizeVariant, primitives: &PrimitiveStore) -> Type {
+    match variant {
+        SizeVariant::Bits32 => primitives.int32,
+        SizeVariant::Bits64 => primitives.int64,
    }
 }

@ -304,6 +294,8 @@ struct BuiltinBuilder<'a> {
    unwrap_ty: (Type, bool),
    option_tvar: TypeVar,

+    list_tvar: TypeVar,
+
    ndarray_dtype_tvar: TypeVar,
    ndarray_ndims_tvar: TypeVar,
    ndarray_copy_ty: (Type, bool),
@ -323,6 +315,9 @@ struct BuiltinBuilder<'a> {

    num_or_ndarray_ty: TypeVar,
    num_or_ndarray_var_map: VarMap,
+
+    /// See [`BuiltinBuilder::build_ndarray_from_shape_factory_function`]
+    ndarray_factory_fn_shape_arg_tvar: TypeVar,
 }

 impl<'a> BuiltinBuilder<'a> {
@ -391,7 +386,19 @@ impl<'a> BuiltinBuilder<'a> {
            unifier.get_fresh_var_with_range(&[num_ty.ty, ndarray_num_ty], Some("T".into()), None);
        let num_or_ndarray_var_map = into_var_map([num_ty, num_or_ndarray_ty]);

-        let list_int32 = unifier.add_ty(TypeEnum::TList { ty: int32 });
+        let list_tvar = if let TypeEnum::TObj { obj_id, params, .. } =
+            &*unifier.get_ty_immutable(primitives.list)
+        {
+            assert_eq!(*obj_id, PrimDef::List.id());
+            iter_type_vars(params).nth(0).unwrap()
+        } else {
+            unreachable!()
+        };
+        let list_int32 = unifier
+            .subst(primitives.list, &into_var_map([TypeVar { id: list_tvar.id, ty: int32 }]))
+            .unwrap();
+
+        let ndarray_factory_fn_shape_arg_tvar = unifier.get_fresh_var(Some("Shape".into()), None);

        BuiltinBuilder {
            unifier,
@ -401,6 +408,8 @@ impl<'a> BuiltinBuilder<'a> {
            unwrap_ty,
            option_tvar,

+            list_tvar,
+
            ndarray_dtype_tvar,
            ndarray_ndims_tvar,
            ndarray_copy_ty,
@ -420,6 +429,8 @@ impl<'a> BuiltinBuilder<'a> {

            num_or_ndarray_ty,
            num_or_ndarray_var_map,
+
+            ndarray_factory_fn_shape_arg_tvar,
        }
    }

@ -438,9 +449,10 @@ impl<'a> BuiltinBuilder<'a> {
            | PrimDef::Float
            | PrimDef::Bool
            | PrimDef::Str
-            | PrimDef::Range
            | PrimDef::None => Self::build_simple_primitive_class(prim),

+            PrimDef::Range | PrimDef::FunRangeInit => self.build_range_class_related(prim),
+
            PrimDef::Exception => self.build_exception_class_related(prim),

            PrimDef::Option
@ -449,6 +461,8 @@ impl<'a> BuiltinBuilder<'a> {
            | PrimDef::OptionUnwrap
            | PrimDef::FunSome => self.build_option_class_related(prim),

+            PrimDef::List => self.build_list_class_related(prim),
+
            PrimDef::NDArray | PrimDef::NDArrayCopy | PrimDef::NDArrayFill => {
                self.build_ndarray_class_related(prim)
            }
@ -470,7 +484,6 @@ impl<'a> BuiltinBuilder<'a> {
            | PrimDef::FunNpEye
            | PrimDef::FunNpIdentity => self.build_ndarray_other_factory_function(prim),

-            PrimDef::FunRange => self.build_range_function(),
            PrimDef::FunStr => self.build_str_function(),

            PrimDef::FunFloor | PrimDef::FunFloor64 | PrimDef::FunCeil | PrimDef::FunCeil64 => {
@ -497,8 +510,6 @@ impl<'a> BuiltinBuilder<'a> {

            PrimDef::FunNpIsNan | PrimDef::FunNpIsInf => self.build_np_float_to_bool_function(prim),

-            PrimDef::FunNpAny | PrimDef::FunNpAll => self.build_np_any_all_function(prim),
-
            PrimDef::FunNpSin
            | PrimDef::FunNpCos
            | PrimDef::FunNpTan
@ -577,7 +588,6 @@ impl<'a> BuiltinBuilder<'a> {
                PrimDef::Float,
                PrimDef::Bool,
                PrimDef::Str,
-                PrimDef::Range,
                PrimDef::None,
            ],
        );
@ -585,6 +595,165 @@ impl<'a> BuiltinBuilder<'a> {
        TopLevelComposer::make_top_level_class_def(prim.id(), None, prim.name().into(), None, None)
    }

+    fn build_range_class_related(&mut self, prim: PrimDef) -> TopLevelDef {
+        debug_assert_prim_is_allowed(prim, &[PrimDef::Range, PrimDef::FunRangeInit]);
+
+        let PrimitiveStore { int32, range, .. } = *self.primitives;
+
+        let make_ctor_signature = |unifier: &mut Unifier| {
+            unifier.add_ty(TypeEnum::TFunc(FunSignature {
+                args: vec![
+                    FuncArg { name: "start".into(), ty: int32, default_value: None },
+                    FuncArg {
+                        name: "stop".into(),
+                        ty: int32,
+                        // placeholder
+                        default_value: Some(SymbolValue::I32(0)),
+                    },
+                    FuncArg {
+                        name: "step".into(),
+                        ty: int32,
+                        default_value: Some(SymbolValue::I32(1)),
+                    },
+                ],
+                ret: range,
+                vars: VarMap::default(),
+            }))
+        };
+
+        match prim {
+            PrimDef::Range => {
+                let fields = vec![
+                    ("start".into(), int32, true),
+                    ("stop".into(), int32, true),
+                    ("step".into(), int32, true),
+                ];
+                let ctor_signature = make_ctor_signature(self.unifier);
+
+                TopLevelDef::Class {
+                    name: prim.name().into(),
+                    object_id: prim.id(),
+                    type_vars: Vec::default(),
+                    fields,
+                    attributes: Vec::default(),
+                    methods: vec![("__init__".into(), ctor_signature, PrimDef::FunRangeInit.id())],
+                    ancestors: Vec::default(),
+                    constructor: Some(ctor_signature),
+                    resolver: None,
+                    loc: None,
+                }
+            }
+
+            PrimDef::FunRangeInit => TopLevelDef::Function {
+                name: prim.name().into(),
+                simple_name: prim.simple_name().into(),
+                signature: make_ctor_signature(self.unifier),
+                var_id: Vec::default(),
+                instance_to_symbol: HashMap::default(),
+                instance_to_stmt: HashMap::default(),
+                resolver: None,
+                codegen_callback: Some(Arc::new(GenCall::new(Box::new(
+                    |ctx, obj, _, args, generator| {
+                        let (zelf_ty, zelf) = obj.unwrap();
+                        let zelf =
+                            zelf.to_basic_value_enum(ctx, generator, zelf_ty)?.into_pointer_value();
+                        let zelf = RangeValue::from_ptr_val(zelf, Some("range"));
+
+                        let mut start = None;
+                        let mut stop = None;
+                        let mut step = None;
+                        let int32 = ctx.ctx.i32_type();
+                        let ty_i32 = ctx.primitives.int32;
+                        for (i, arg) in args.iter().enumerate() {
+                            if arg.0 == Some("start".into()) {
+                                start = Some(
+                                    arg.1
+                                        .clone()
+                                        .to_basic_value_enum(ctx, generator, ty_i32)?
+                                        .into_int_value(),
+                                );
+                            } else if arg.0 == Some("stop".into()) {
+                                stop = Some(
+                                    arg.1
+                                        .clone()
+                                        .to_basic_value_enum(ctx, generator, ty_i32)?
+                                        .into_int_value(),
+                                );
+                            } else if arg.0 == Some("step".into()) {
+                                step = Some(
+                                    arg.1
+                                        .clone()
+                                        .to_basic_value_enum(ctx, generator, ty_i32)?
+                                        .into_int_value(),
+                                );
+                            } else if i == 0 {
+                                start = Some(
+                                    arg.1
+                                        .clone()
+                                        .to_basic_value_enum(ctx, generator, ty_i32)?
+                                        .into_int_value(),
+                                );
+                            } else if i == 1 {
+                                stop = Some(
+                                    arg.1
+                                        .clone()
+                                        .to_basic_value_enum(ctx, generator, ty_i32)?
+                                        .into_int_value(),
+                                );
+                            } else if i == 2 {
+                                step = Some(
+                                    arg.1
+                                        .clone()
+                                        .to_basic_value_enum(ctx, generator, ty_i32)?
+                                        .into_int_value(),
+                                );
+                            }
+                        }
+                        let step = match step {
+                            Some(step) => {
+                                // assert step != 0, throw exception if not
+                                let not_zero = ctx
+                                    .builder
+                                    .build_int_compare(
+                                        IntPredicate::NE,
+                                        step,
+                                        step.get_type().const_zero(),
+                                        "range_step_ne",
+                                    )
+                                    .unwrap();
+                                ctx.make_assert(
+                                    generator,
+                                    not_zero,
+                                    "0:ValueError",
+                                    "range() step must not be zero",
+                                    [None, None, None],
+                                    ctx.current_loc,
+                                );
+                                step
+                            }
+                            None => int32.const_int(1, false),
+                        };
+                        let stop = stop.unwrap_or_else(|| {
+                            let v = start.unwrap();
+                            start = None;
+                            v
+                        });
+                        let start = start.unwrap_or_else(|| int32.const_zero());
+
+                        zelf.store_start(ctx, start);
+                        zelf.store_end(ctx, stop);
+                        zelf.store_step(ctx, step);
+
+                        Ok(Some(zelf.as_base_value().into()))
+                    },
+                )))),
+                loc: None,
+            },
+
+            _ => unreachable!(),
+        }
+    }
+
    /// Build the class `Exception` and its associated methods.
    fn build_exception_class_related(&self, prim: PrimDef) -> TopLevelDef {
        // NOTE: currently only contains the class `Exception`
@ -598,6 +767,7 @@ impl<'a> BuiltinBuilder<'a> {
                object_id: prim.id(),
                type_vars: Vec::default(),
                fields: make_exception_fields(int32, int64, str),
+                attributes: Vec::default(),
                methods: Vec::default(),
                ancestors: vec![],
                constructor: None,
@ -626,7 +796,8 @@ impl<'a> BuiltinBuilder<'a> {
                name: prim.name().into(),
                object_id: prim.id(),
                type_vars: vec![self.option_tvar.ty],
-                fields: vec![],
+                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),
@ -727,6 +898,27 @@ impl<'a> BuiltinBuilder<'a> {
        }
    }

+    fn build_list_class_related(&self, prim: PrimDef) -> TopLevelDef {
+        debug_assert_prim_is_allowed(prim, &[PrimDef::List]);
+
+        match prim {
+            PrimDef::List => TopLevelDef::Class {
+                name: prim.name().into(),
+                object_id: prim.id(),
+                type_vars: vec![self.list_tvar.ty],
+                fields: Vec::default(),
+                attributes: Vec::default(),
+                methods: Vec::default(),
+                ancestors: Vec::default(),
+                constructor: None,
+                resolver: None,
+                loc: None,
+            },
+
+            _ => unreachable!(),
+        }
+    }
+
    /// Build the class `ndarray` and its associated methods.
    fn build_ndarray_class_related(&self, prim: PrimDef) -> TopLevelDef {
        debug_assert_prim_is_allowed(
@ -740,6 +932,7 @@ impl<'a> BuiltinBuilder<'a> {
                object_id: prim.id(),
                type_vars: vec![self.ndarray_dtype_tvar.ty, self.ndarray_ndims_tvar.ty],
                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),
@ -760,8 +953,9 @@ impl<'a> BuiltinBuilder<'a> {
                resolver: None,
                codegen_callback: Some(Arc::new(GenCall::new(Box::new(
                    |ctx, obj, fun, args, generator| {
-                        gen_ndarray_copy(ctx, &obj, fun, &args, generator)
-                            .map(|val| Some(val.as_basic_value_enum()))
+                        todo!()
+                        // gen_ndarray_copy(ctx, &obj, fun, &args, generator)
+                        //     .map(|val| Some(val.as_basic_value_enum()))
                    },
                )))),
                loc: None,
@ -777,8 +971,9 @@ impl<'a> BuiltinBuilder<'a> {
                resolver: None,
                codegen_callback: Some(Arc::new(GenCall::new(Box::new(
                    |ctx, obj, fun, args, generator| {
-                        gen_ndarray_fill(ctx, &obj, fun, &args, generator)?;
-                        Ok(None)
+                        todo!()
+                        // gen_ndarray_fill(ctx, &obj, fun, &args, generator)?;
+                        // Ok(None)
                    },
                )))),
                loc: None,
@ -858,7 +1053,7 @@ impl<'a> BuiltinBuilder<'a> {
        );

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

        let ndarray_int_sized =
            make_ndarray_ty(self.unifier, self.primitives, Some(int_sized), Some(common_ndim.ty));
@ -883,7 +1078,7 @@ 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.of_int(&ctx.primitives);
+                let ret_elem_ty = size_variant_to_int_type(size_variant, &ctx.primitives);
                Ok(Some(builtin_fns::call_round(generator, ctx, (arg_ty, arg), ret_elem_ty)?))
            }),
        )
@ -924,7 +1119,7 @@ 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.of_int(self.primitives);
+        let int_sized = size_variant_to_int_type(size_variant, self.primitives);
        let ndarray_int_sized =
            make_ndarray_ty(self.unifier, self.primitives, Some(int_sized), Some(common_ndim.ty));

@ -947,7 +1142,7 @@ 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.of_int(&ctx.primitives);
+                let ret_elem_ty = size_variant_to_int_type(size_variant, &ctx.primitives);
                let func = match kind {
                    Kind::Ceil => builtin_fns::call_ceil,
                    Kind::Floor => builtin_fns::call_floor,
@ -957,29 +1152,55 @@ impl<'a> BuiltinBuilder<'a> {
        )
    }

-    /// Build ndarray factory functions that only take in an argument `shape` of type `list[int32]` and return an ndarray.
+    /// Build ndarray factory functions that only take in an argument `shape`.
+    ///
+    /// `shape` can be a tuple of int32s, a list of int32s, or a scalar int32.
    fn build_ndarray_from_shape_factory_function(&mut self, prim: PrimDef) -> TopLevelDef {
        debug_assert_prim_is_allowed(
            prim,
            &[PrimDef::FunNpNDArray, PrimDef::FunNpEmpty, PrimDef::FunNpZeros, PrimDef::FunNpOnes],
        );

+        // NOTE: on `ndarray_factory_fn_shape_arg_tvar` and
+        // the `param_ty` for `create_fn_by_codegen`.
+        //
+        // Ideally, we should have created a [`TypeVar`] to define all possible input
+        // types for the parameter "shape" like so:
+        // ```rust
+        // self.unifier.get_fresh_var_with_range(
+        //   &[int32, list_int32, /* and more... */],
+        //   Some("T".into()), None)
+        // )
+        // ```
+        //
+        // However, there is (currently) no way to type a tuple of arbitrary length in `nac3core`.
+        //
+        // And this is the best we could do:
+        // ```rust
+        // &[ int32, list_int32, tuple_1_int32, tuple_2_int32, tuple_3_int32, ... ],
+        // ```
+        //
+        // But this is not ideal.
+        //
+        // Instead, we delegate the responsibility of typechecking
+        // to [`typecheck::type_inferencer::Inferencer::fold_numpy_function_call_shape_argument`],
+        // and use a dummy [`TypeVar`] `ndarray_factory_fn_shape_arg_tvar` as a placeholder for `param_ty`.
+
        create_fn_by_codegen(
            self.unifier,
            &VarMap::new(),
            prim.name(),
            self.ndarray_float,
-            // We are using List[int32] here, as I don't know a way to specify an n-tuple bound on a
-            // type variable
-            &[(self.list_int32, "shape")],
+            &[(self.ndarray_factory_fn_shape_arg_tvar.ty, "shape")],
            Box::new(move |ctx, obj, fun, args, generator| {
-                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()))
+                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()))
            }),
        )
    }
@ -1025,8 +1246,9 @@ impl<'a> BuiltinBuilder<'a> {
                    resolver: None,
                    codegen_callback: Some(Arc::new(GenCall::new(Box::new(
                        |ctx, obj, fun, args, generator| {
-                            gen_ndarray_array(ctx, &obj, fun, &args, generator)
-                                .map(|val| Some(val.as_basic_value_enum()))
+                            todo!()
+                            // gen_ndarray_array(ctx, &obj, fun, &args, generator)
+                            //     .map(|val| Some(val.as_basic_value_enum()))
                        },
                    )))),
                    loc: None,
@ -1044,8 +1266,9 @@ impl<'a> BuiltinBuilder<'a> {
                    // type variable
                    &[(self.list_int32, "shape"), (tv.ty, "fill_value")],
                    Box::new(move |ctx, obj, fun, args, generator| {
-                        gen_ndarray_full(ctx, &obj, fun, &args, generator)
-                            .map(|val| Some(val.as_basic_value_enum()))
+                        todo!()
+                        // gen_ndarray_full(ctx, &obj, fun, &args, generator)
+                        //     .map(|val| Some(val.as_basic_value_enum()))
                    }),
                )
            }
@ -1077,8 +1300,9 @@ impl<'a> BuiltinBuilder<'a> {
                    resolver: None,
                    codegen_callback: Some(Arc::new(GenCall::new(Box::new(
                        |ctx, obj, fun, args, generator| {
-                            gen_ndarray_eye(ctx, &obj, fun, &args, generator)
-                                .map(|val| Some(val.as_basic_value_enum()))
+                            todo!()
+                            // gen_ndarray_eye(ctx, &obj, fun, &args, generator)
+                            //     .map(|val| Some(val.as_basic_value_enum()))
                        },
                    )))),
                    loc: None,
@ -1091,139 +1315,15 @@ impl<'a> BuiltinBuilder<'a> {
                self.ndarray_float_2d,
                &[(int32, "n")],
                Box::new(|ctx, obj, fun, args, generator| {
-                    gen_ndarray_identity(ctx, &obj, fun, &args, generator)
-                        .map(|val| Some(val.as_basic_value_enum()))
+                    todo!()
+                    // gen_ndarray_identity(ctx, &obj, fun, &args, generator)
+                    //     .map(|val| Some(val.as_basic_value_enum()))
                }),
            ),
            _ => unreachable!(),
        }
    }

-    /// Build the `range()` function.
-    fn build_range_function(&mut self) -> TopLevelDef {
-        let prim = PrimDef::FunRange;
-
-        let PrimitiveStore { int32, range, .. } = *self.primitives;
-
-        TopLevelDef::Function {
-            name: prim.name().into(),
-            simple_name: prim.simple_name().into(),
-            signature: self.unifier.add_ty(TypeEnum::TFunc(FunSignature {
-                args: vec![
-                    FuncArg { name: "start".into(), ty: int32, default_value: None },
-                    FuncArg {
-                        name: "stop".into(),
-                        ty: int32,
-                        // placeholder
-                        default_value: Some(SymbolValue::I32(0)),
-                    },
-                    FuncArg {
-                        name: "step".into(),
-                        ty: int32,
-                        default_value: Some(SymbolValue::I32(1)),
-                    },
-                ],
-                ret: range,
-                vars: VarMap::default(),
-            })),
-            var_id: Vec::default(),
-            instance_to_symbol: HashMap::default(),
-            instance_to_stmt: HashMap::default(),
-            resolver: None,
-            codegen_callback: Some(Arc::new(GenCall::new(Box::new(
-                |ctx, _, _, args, generator| {
-                    let mut start = None;
-                    let mut stop = None;
-                    let mut step = None;
-                    let int32 = ctx.ctx.i32_type();
-                    let ty_i32 = ctx.primitives.int32;
-                    for (i, arg) in args.iter().enumerate() {
-                        if arg.0 == Some("start".into()) {
-                            start = Some(
-                                arg.1
-                                    .clone()
-                                    .to_basic_value_enum(ctx, generator, ty_i32)?
-                                    .into_int_value(),
-                            );
-                        } else if arg.0 == Some("stop".into()) {
-                            stop = Some(
-                                arg.1
-                                    .clone()
-                                    .to_basic_value_enum(ctx, generator, ty_i32)?
-                                    .into_int_value(),
-                            );
-                        } else if arg.0 == Some("step".into()) {
-                            step = Some(
-                                arg.1
-                                    .clone()
-                                    .to_basic_value_enum(ctx, generator, ty_i32)?
-                                    .into_int_value(),
-                            );
-                        } else if i == 0 {
-                            start = Some(
-                                arg.1
-                                    .clone()
-                                    .to_basic_value_enum(ctx, generator, ty_i32)?
-                                    .into_int_value(),
-                            );
-                        } else if i == 1 {
-                            stop = Some(
-                                arg.1
-                                    .clone()
-                                    .to_basic_value_enum(ctx, generator, ty_i32)?
-                                    .into_int_value(),
-                            );
-                        } else if i == 2 {
-                            step = Some(
-                                arg.1
-                                    .clone()
-                                    .to_basic_value_enum(ctx, generator, ty_i32)?
-                                    .into_int_value(),
-                            );
-                        }
-                    }
-                    let step = match step {
-                        Some(step) => {
-                            // assert step != 0, throw exception if not
-                            let not_zero = ctx
-                                .builder
-                                .build_int_compare(
-                                    IntPredicate::NE,
-                                    step,
-                                    step.get_type().const_zero(),
-                                    "range_step_ne",
-                                )
-                                .unwrap();
-                            ctx.make_assert(
-                                generator,
-                                not_zero,
-                                "0:ValueError",
-                                "range() step must not be zero",
-                                [None, None, None],
-                                ctx.current_loc,
-                            );
-                            step
-                        }
-                        None => int32.const_int(1, false),
-                    };
-                    let stop = stop.unwrap_or_else(|| {
-                        let v = start.unwrap();
-                        start = None;
-                        v
-                    });
-                    let start = start.unwrap_or_else(|| int32.const_zero());
-
-                    let ptr = RangeType::new(ctx.ctx).new_value(generator, ctx, Some("range"));
-                    ptr.store_start(ctx, start);
-                    ptr.store_end(ctx, stop);
-                    ptr.store_step(ctx, step);
-                    Ok(Some(ptr.as_base_value().into()))
-                },
-            )))),
-            loc: None,
-        }
-    }
-
    /// Build the `str()` function.
    fn build_str_function(&mut self) -> TopLevelDef {
        let prim = PrimDef::FunStr;
@ -1301,7 +1401,13 @@ impl<'a> BuiltinBuilder<'a> {
        let PrimitiveStore { uint64, int32, .. } = *self.primitives;

        let tvar = self.unifier.get_fresh_var(Some("L".into()), None);
-        let list = self.unifier.add_ty(TypeEnum::TList { ty: tvar.ty });
+        let list = self
+            .unifier
+            .subst(
+                self.primitives.list,
+                &into_var_map([TypeVar { id: self.list_tvar.id, ty: tvar.ty }]),
+            )
+            .unwrap();
        let ndims = self.unifier.get_fresh_const_generic_var(uint64, Some("N".into()), None);
        let ndarray = make_ndarray_ty(self.unifier, self.primitives, Some(tvar.ty), Some(ndims.ty));

@ -1333,7 +1439,7 @@ impl<'a> BuiltinBuilder<'a> {
                        Some(calculate_len_for_slice_range(generator, ctx, start, end, step).into())
                    } else {
                        match &*ctx.unifier.get_ty_immutable(arg_ty) {
-                            TypeEnum::TList { .. } => {
+                            TypeEnum::TObj { obj_id, .. } if *obj_id == PrimDef::List.id() => {
                                let int32 = ctx.ctx.i32_type();
                                let zero = int32.const_zero();
                                let len = ctx
@ -1759,24 +1865,6 @@ impl<'a> BuiltinBuilder<'a> {
        }
    }

-    fn build_np_any_all_function(&mut self, prim: PrimDef) -> TopLevelDef {
-        debug_assert_prim_is_allowed(prim, &[PrimDef::FunNpAny, PrimDef::FunNpAll]);
-        let param_ty = &[(self.ndarray_num_ty, "a")];
-        let ret_ty = self.primitives.bool;
-        let var_map = &into_var_map([]);
-        let codegen_callback: Box<GenCallCallback> =
-            Box::new(move |ctx, obj, fun, args, generator| {
-                let func = match prim {
-                    PrimDef::FunNpAny => gen_ndarray_any,
-                    PrimDef::FunNpAll => gen_ndarray_all,
-                    _ => unreachable!(),
-                };
-                func(ctx, &obj, fun, &args, generator).map(|val| Some(val.as_basic_value_enum()))
-            });
-
-        create_fn_by_codegen(self.unifier, var_map, prim.name(), ret_ty, param_ty, codegen_callback)
-    }
-
    fn create_method(prim: PrimDef, method_ty: Type) -> (StrRef, Type, DefinitionId) {
        (prim.simple_name().into(), method_ty, prim.id())
    }
--- a/nac3core/src/toplevel/composer.rs
+++ b/nac3core/src/toplevel/composer.rs
@ -1057,7 +1057,14 @@ impl TopLevelComposer {
        let (keyword_list, core_config) = core_info;
        let mut class_def = class_def.write();
        let TopLevelDef::Class {
-            object_id, ancestors, fields, methods, resolver, type_vars, ..
+            object_id,
+            ancestors,
+            fields,
+            attributes,
+            methods,
+            resolver,
+            type_vars,
+            ..
        } = &mut *class_def
        else {
            unreachable!("here must be toplevel class def");
@ -1073,10 +1080,14 @@ impl TopLevelComposer {
            class_body_ast,
            _class_ancestor_def,
            class_fields_def,
+            class_attributes_def,
            class_methods_def,
            class_type_vars_def,
            class_resolver,
-        ) = (*object_id, *name, bases, body, ancestors, fields, methods, type_vars, resolver);
+        ) = (
+            *object_id, *name, bases, body, ancestors, fields, attributes, methods, type_vars,
+            resolver,
+        );

        let class_resolver = class_resolver.as_ref().unwrap();
        let class_resolver = class_resolver.as_ref();
@ -1285,34 +1296,74 @@ impl TopLevelComposer {
                        .unify(method_dummy_ty, method_type)
                        .map_err(|e| HashSet::from([e.to_display(unifier).to_string()]))?;
                }
-                ast::StmtKind::AnnAssign { target, annotation, value: None, .. } => {
+                ast::StmtKind::AnnAssign { target, annotation, value, .. } => {
                    if let ast::ExprKind::Name { id: attr, .. } = &target.node {
                        if defined_fields.insert(attr.to_string()) {
                            let dummy_field_type = unifier.get_dummy_var().ty;

-                            // handle Kernel[T], KernelInvariant[T]
-                            let (annotation, mutable) = match &annotation.node {
-                                ast::ExprKind::Subscript { value, slice, .. }
-                                    if matches!(
-                                        &value.node,
-                                        ast::ExprKind::Name { id, .. } if id == &core_config.kernel_invariant_ann.into()
-                                    ) =>
-                                {
-                                    (slice, false)
+                            let annotation = match value {
+                                None => {
+                                    // handle Kernel[T], KernelInvariant[T]
+                                    let (annotation, mutable) = match &annotation.node {
+                                        ast::ExprKind::Subscript { value, slice, .. }
+                                            if matches!(
+                                                &value.node,
+                                                ast::ExprKind::Name { id, .. } if id == &core_config.kernel_invariant_ann.into()
+                                            ) =>
+                                        {
+                                            (slice, false)
+                                        }
+                                        ast::ExprKind::Subscript { value, slice, .. }
+                                            if matches!(
+                                                &value.node,
+                                                ast::ExprKind::Name { id, .. } if core_config.kernel_ann.map_or(false, |c| id == &c.into())
+                                            ) =>
+                                        {
+                                            (slice, true)
+                                        }
+                                        _ if core_config.kernel_ann.is_none() => (annotation, true),
+                                        _ => continue, // ignore fields annotated otherwise
+                                    };
+                                    class_fields_def.push((*attr, dummy_field_type, mutable));
+                                    annotation
                                }
-                                ast::ExprKind::Subscript { value, slice, .. }
-                                    if matches!(
-                                        &value.node,
-                                        ast::ExprKind::Name { id, .. } if core_config.kernel_ann.map_or(false, |c| id == &c.into())
-                                    ) =>
-                                {
-                                    (slice, true)
-                                }
-                                _ if core_config.kernel_ann.is_none() => (annotation, true),
-                                _ => continue, // ignore fields annotated otherwise
-                            };
-                            class_fields_def.push((*attr, dummy_field_type, mutable));
+                                // Supporting Class Attributes
+                                Some(boxed_expr) => {
+                                    // Class attributes are set as immutable regardless
+                                    let (annotation, _) = match &annotation.node {
+                                        ast::ExprKind::Subscript { slice, .. } => (slice, false),
+                                        _ if core_config.kernel_ann.is_none() => (annotation, false),
+                                        _ => continue,
+                                    };

+                                    match &**boxed_expr {
+                                        ast::Located {location: _, custom: (), node: ast::ExprKind::Constant { value: v, kind: _ }} => {
+                                            // Restricting the types allowed to be defined as class attributes
+                                            match v {
+                                                ast::Constant::Bool(_) | ast::Constant::Str(_) | ast::Constant::Int(_) | ast::Constant::Float(_) => {}
+                                                _ => {
+                                                        return Err(HashSet::from([
+                                                        format!(
+                                                            "unsupported statement in class definition body (at {})",
+                                                            b.location
+                                                        ),
+                                                    ]))
+                                                }
+                                            }
+                                            class_attributes_def.push((*attr, dummy_field_type, v.clone()));
+                                        }
+                                        _ => {
+                                            return Err(HashSet::from([
+                                                format!(
+                                                    "unsupported statement in class definition body (at {})",
+                                                    b.location
+                                                ),
+                                            ]))
+                                        }
+                                    }
+                                    annotation
+                                }
+                            };
                            let parsed_annotation = parse_ast_to_type_annotation_kinds(
                                class_resolver,
                                temp_def_list,
@ -1384,7 +1435,14 @@ impl TopLevelComposer {
        type_var_to_concrete_def: &mut HashMap<Type, TypeAnnotation>,
    ) -> Result<(), HashSet<String>> {
        let TopLevelDef::Class {
-            object_id, ancestors, fields, methods, resolver, type_vars, ..
+            object_id,
+            ancestors,
+            fields,
+            attributes,
+            methods,
+            resolver,
+            type_vars,
+            ..
        } = class_def
        else {
            unreachable!("here must be class def ast")
@ -1393,10 +1451,11 @@ impl TopLevelComposer {
            _class_id,
            class_ancestor_def,
            class_fields_def,
+            class_attribute_def,
            class_methods_def,
            _class_type_vars_def,
            _class_resolver,
-        ) = (*object_id, ancestors, fields, methods, type_vars, resolver);
+        ) = (*object_id, ancestors, fields, attributes, methods, type_vars, resolver);

        // since when this function is called, the ancestors of the direct parent
        // are supposed to be already handled, so we only need to deal with the direct parent
@ -1407,7 +1466,7 @@ impl TopLevelComposer {

        let base = temp_def_list.get(id.0).unwrap();
        let base = base.read();
-        let TopLevelDef::Class { methods, fields, .. } = &*base else {
+        let TopLevelDef::Class { methods, fields, attributes, .. } = &*base else {
            unreachable!("must be top level class def")
        };

@ -1449,7 +1508,7 @@ impl TopLevelComposer {
            }
        }
        // use the new_child_methods to replace all the elements in `class_methods_def`
-        class_methods_def.drain(..);
+        class_methods_def.clear();
        class_methods_def.extend(new_child_methods);

        // handle class fields
@ -1459,7 +1518,9 @@ impl TopLevelComposer {
            let to_be_added = (*anc_field_name, *anc_field_ty, *mutable);
            // find if there is a fields with the same name in the child class
            for (class_field_name, ..) in &*class_fields_def {
-                if class_field_name == anc_field_name {
+                if class_field_name == anc_field_name
+                    || attributes.iter().any(|f| f.0 == *class_field_name)
+                {
                    return Err(HashSet::from([format!(
                        "field `{class_field_name}` has already declared in the ancestor classes"
                    )]));
@ -1467,14 +1528,33 @@ impl TopLevelComposer {
            }
            new_child_fields.push(to_be_added);
        }
+
+        // handle class attributes
+        let mut new_child_attributes: Vec<(StrRef, Type, ast::Constant)> = Vec::new();
+        for (anc_attr_name, anc_attr_ty, attr_value) in attributes {
+            let to_be_added = (*anc_attr_name, *anc_attr_ty, attr_value.clone());
+            // find if there is a attribute with the same name in the child class
+            for (class_attr_name, ..) in &*class_attribute_def {
+                if class_attr_name == anc_attr_name
+                    || fields.iter().any(|f| f.0 == *class_attr_name)
+                {
+                    return Err(HashSet::from([format!(
+                        "attribute `{class_attr_name}` has already declared in the ancestor classes"
+                    )]));
+                }
+            }
+            new_child_attributes.push(to_be_added);
+        }
+
        for (class_field_name, class_field_ty, mutable) in &*class_fields_def {
            if !is_override.contains(class_field_name) {
                new_child_fields.push((*class_field_name, *class_field_ty, *mutable));
            }
        }
-        class_fields_def.drain(..);
+        class_fields_def.clear();
        class_fields_def.extend(new_child_fields);
-
+        class_attribute_def.clear();
+        class_attribute_def.extend(new_child_attributes);
        Ok(())
    }

--- a/nac3core/src/toplevel/helper.rs
+++ b/nac3core/src/toplevel/helper.rs
@ -2,7 +2,7 @@ use std::convert::TryInto;

 use crate::symbol_resolver::SymbolValue;
 use crate::toplevel::numpy::unpack_ndarray_var_tys;
-use crate::typecheck::typedef::{into_var_map, Mapping, TypeVarId, VarMap};
+use crate::typecheck::typedef::{into_var_map, iter_type_vars, Mapping, TypeVarId, VarMap};
 use nac3parser::ast::{Constant, Location};
 use strum::IntoEnumIterator;
 use strum_macros::EnumIter;
@ -12,6 +12,7 @@ use super::*;
 /// All primitive types and functions in nac3core.
 #[derive(Clone, Copy, Debug, EnumIter, PartialEq, Eq)]
 pub enum PrimDef {
+    // Classes
    Int32,
    Int64,
    Float,
@ -23,10 +24,13 @@ pub enum PrimDef {
    UInt32,
    UInt64,
    Option,
+    List,
+    NDArray,
+
+    // Member Functions
    OptionIsSome,
    OptionIsNone,
    OptionUnwrap,
-    NDArray,
    NDArrayCopy,
    NDArrayFill,
    FunInt32,
@ -45,7 +49,7 @@ pub enum PrimDef {
    FunRound,
    FunRound64,
    FunNpRound,
-    FunRange,
+    FunRangeInit,
    FunStr,
    FunBool,
    FunFloor,
@ -99,9 +103,9 @@ pub enum PrimDef {
    FunNpLdExp,
    FunNpHypot,
    FunNpNextAfter,
+
+    // Top-Level Functions
    FunSome,
-    FunNpAny,
-    FunNpAll,
 }

 /// Associated details of a [`PrimDef`]
@ -179,6 +183,7 @@ impl PrimDef {
            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")),
@ -198,7 +203,7 @@ impl PrimDef {
            PrimDef::FunRound => fun("round", None),
            PrimDef::FunRound64 => fun("round64", None),
            PrimDef::FunNpRound => fun("np_round", None),
-            PrimDef::FunRange => fun("range", None),
+            PrimDef::FunRangeInit => fun("range.__init__", Some("__init__")),
            PrimDef::FunStr => fun("str", None),
            PrimDef::FunBool => fun("bool", None),
            PrimDef::FunFloor => fun("floor", None),
@ -253,8 +258,6 @@ impl PrimDef {
            PrimDef::FunNpHypot => fun("np_hypot", None),
            PrimDef::FunNpNextAfter => fun("np_nextafter", None),
            PrimDef::FunSome => fun("Some", None),
-            PrimDef::FunNpAny => fun("np_any", None),
-            PrimDef::FunNpAll => fun("np_all", None),
        }
    }
 }
@ -358,7 +361,13 @@ impl TopLevelComposer {
        });
        let range = unifier.add_ty(TypeEnum::TObj {
            obj_id: PrimDef::Range.id(),
-            fields: HashMap::new(),
+            fields: [
+                ("start".into(), (int32, true)),
+                ("stop".into(), (int32, true)),
+                ("step".into(), (int32, true)),
+            ]
+            .into_iter()
+            .collect(),
            params: VarMap::new(),
        });
        let str = unifier.add_ty(TypeEnum::TObj {
@ -414,6 +423,13 @@ impl TopLevelComposer {
            _ => unreachable!(),
        };

+        let list_elem_tvar = unifier.get_fresh_var(Some("list_elem".into()), None);
+        let list = unifier.add_ty(TypeEnum::TObj {
+            obj_id: PrimDef::List.id(),
+            fields: Mapping::new(),
+            params: into_var_map([list_elem_tvar]),
+        });
+
        let ndarray_dtype_tvar = unifier.get_fresh_var(Some("ndarray_dtype".into()), None);
        let ndarray_ndims_tvar =
            unifier.get_fresh_const_generic_var(size_t_ty, Some("ndarray_ndims".into()), None);
@ -455,6 +471,7 @@ impl TopLevelComposer {
            str,
            exception,
            option,
+            list,
            ndarray,
            size_t,
        };
@ -478,6 +495,7 @@ impl TopLevelComposer {
            object_id: obj_id,
            type_vars: Vec::default(),
            fields: Vec::default(),
+            attributes: Vec::default(),
            methods: Vec::default(),
            ancestors: Vec::default(),
            constructor,
@ -891,7 +909,9 @@ pub fn arraylike_flatten_element_type(unifier: &mut Unifier, ty: Type) -> Type {
            unpack_ndarray_var_tys(unifier, ty).0
        }

-        TypeEnum::TList { ty } => arraylike_flatten_element_type(unifier, *ty),
+        TypeEnum::TObj { obj_id, params, .. } if *obj_id == PrimDef::List.id() => {
+            arraylike_flatten_element_type(unifier, iter_type_vars(params).next().unwrap().ty)
+        }
        _ => ty,
    }
 }
@ -912,7 +932,9 @@ pub fn arraylike_get_ndims(unifier: &mut Unifier, ty: Type) -> u64 {
            u64::try_from(values[0].clone()).unwrap()
        }

-        TypeEnum::TList { ty } => arraylike_get_ndims(unifier, *ty) + 1,
+        TypeEnum::TObj { obj_id, params, .. } if *obj_id == PrimDef::List.id() => {
+            arraylike_get_ndims(unifier, iter_type_vars(params).next().unwrap().ty) + 1
+        }
        _ => 0,
    }
 }
--- a/nac3core/src/toplevel/mod.rs
+++ b/nac3core/src/toplevel/mod.rs
@ -103,6 +103,10 @@ pub enum TopLevelDef {
        ///
        /// Name and type is mutable.
        fields: Vec<(StrRef, Type, bool)>,
+        /// Class Attributes.
+        ///
+        /// Name, type, value.
+        attributes: Vec<(StrRef, Type, ast::Constant)>,
        /// Class methods, pointing to the corresponding function definition.
        methods: Vec<(StrRef, Type, DefinitionId)>,
        /// Ancestor classes, including itself.
--- 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(239)]\n}\n",
+    "Function {\nname: \"Generic_A.fun\",\nsig: \"fn[[a:int32], V]\",\nvar_id: [TypeVarId(245)]\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[typevar228]\", \"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: [\"typevar228\"]\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",
    "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(241)]\n}\n",
-    "Function {\nname: \"A.fun\",\nsig: \"fn[[a:T], V]\",\nvar_id: [TypeVarId(246)]\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: \"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[typevar227, typevar228]\"],\nfields: [\"a\", \"b\"],\nmethods: [(\"__init__\", \"fn[[a:A[float, bool], b:B], none]\"), (\"fun\", \"fn[[a:A[float, bool]], A[bool, int32]]\")],\ntype_vars: [\"typevar227\", \"typevar228\"]\n}\n",
+    "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",
    "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(247)]\n}\n",
+    "Function {\nname: \"A.foo\",\nsig: \"fn[[a:T, b:V], none]\",\nvar_id: [TypeVarId(253)]\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(255)]\n}\n",
+    "Function {\nname: \"ff\",\nsig: \"fn[[a:T], V]\",\nvar_id: [TypeVarId(261)]\n}\n",
 ]
--- a/nac3core/src/toplevel/test.rs
+++ b/nac3core/src/toplevel/test.rs
@ -1,3 +1,6 @@
+use super::*;
+use crate::toplevel::helper::PrimDef;
+use crate::typecheck::typedef::into_var_map;
 use crate::{
    codegen::CodeGenContext,
    symbol_resolver::{SymbolResolver, ValueEnum},
@ -14,8 +17,6 @@ use parking_lot::Mutex;
 use std::{collections::HashMap, sync::Arc};
 use test_case::test_case;

-use super::*;
-
 struct ResolverInternal {
    id_to_type: Mutex<HashMap<StrRef, Type>>,
    id_to_def: Mutex<HashMap<StrRef, DefinitionId>>,
@ -775,8 +776,15 @@ fn make_internal_resolver_with_tvar(
    unifier: &mut Unifier,
    print: bool,
 ) -> Arc<ResolverInternal> {
+    let list_elem_tvar = unifier.get_fresh_var(Some("list_elem".into()), None);
+    let list = unifier.add_ty(TypeEnum::TObj {
+        obj_id: PrimDef::List.id(),
+        fields: HashMap::new(),
+        params: into_var_map([list_elem_tvar]),
+    });
+
    let res: Arc<ResolverInternal> = ResolverInternal {
-        id_to_def: Mutex::default(),
+        id_to_def: Mutex::new(HashMap::from([("list".into(), PrimDef::List.id())])),
        id_to_type: tvars
            .into_iter()
            .map(|(name, range)| {
@ -790,7 +798,7 @@ fn make_internal_resolver_with_tvar(
            })
            .collect::<HashMap<_, _>>()
            .into(),
-        class_names: Mutex::default(),
+        class_names: Mutex::new(HashMap::from([("list".into(), list)])),
    }
    .into();
    if print {
--- a/nac3core/src/toplevel/type_annotation.rs
+++ b/nac3core/src/toplevel/type_annotation.rs
@ -18,7 +18,6 @@ pub enum TypeAnnotation {
    TypeVar(Type),
    /// A `Literal` allowing a subset of literals.
    Literal(Vec<Constant>),
-    List(Box<TypeAnnotation>),
    Tuple(Vec<TypeAnnotation>),
 }

@ -51,7 +50,6 @@ impl TypeAnnotation {
                format!("Literal({})", values.iter().map(|v| format!("{v:?}")).join(", "))
            }
            Virtual(ty) => format!("virtual[{}]", ty.stringify(unifier)),
-            List(ty) => format!("list[{}]", ty.stringify(unifier)),
            Tuple(types) => {
                format!(
                    "tuple[{}]",
@ -145,9 +143,7 @@ pub fn parse_ast_to_type_annotation_kinds<T, S: std::hash::BuildHasher + Clone>(
         slice: &ast::Expr<T>,
         unifier: &mut Unifier,
         mut locked: HashMap<DefinitionId, Vec<Type>, S>| {
-            if ["virtual".into(), "Generic".into(), "list".into(), "tuple".into(), "Option".into()]
-                .contains(id)
-            {
+            if ["virtual".into(), "Generic".into(), "tuple".into(), "Option".into()].contains(id) {
                return Err(HashSet::from([format!(
                    "keywords cannot be class name (at {})",
                    expr.location
@ -236,23 +232,6 @@ pub fn parse_ast_to_type_annotation_kinds<T, S: std::hash::BuildHasher + Clone>(
            Ok(TypeAnnotation::Virtual(def.into()))
        }

-        // list
-        ast::ExprKind::Subscript { value, slice, .. }
-            if {
-                matches!(&value.node, ast::ExprKind::Name { id, .. } if id == &"list".into())
-            } =>
-        {
-            let def_ann = parse_ast_to_type_annotation_kinds(
-                resolver,
-                top_level_defs,
-                unifier,
-                primitives,
-                slice.as_ref(),
-                locked,
-            )?;
-            Ok(TypeAnnotation::List(def_ann.into()))
-        }
-
        // option
        ast::ExprKind::Subscript { value, slice, .. }
            if {
@ -470,6 +449,7 @@ pub fn get_type_from_type_annotation_kinds(
                }
                result
            };
+            // Class Attributes keep a copy with Class Definition and are not added to objects
            let mut tobj_fields = methods
                .iter()
                .map(|(name, ty, _)| {
@ -515,15 +495,6 @@ pub fn get_type_from_type_annotation_kinds(
            )?;
            Ok(unifier.add_ty(TypeEnum::TVirtual { ty }))
        }
-        TypeAnnotation::List(ty) => {
-            let ty = get_type_from_type_annotation_kinds(
-                top_level_defs,
-                unifier,
-                ty.as_ref(),
-                subst_list,
-            )?;
-            Ok(unifier.add_ty(TypeEnum::TList { ty }))
-        }
        TypeAnnotation::Tuple(tys) => {
            let tys = tys
                .iter()
@ -564,7 +535,7 @@ pub fn get_type_var_contained_in_type_annotation(ann: &TypeAnnotation) -> Vec<Ty
    let mut result: Vec<TypeAnnotation> = Vec::new();
    match ann {
        TypeAnnotation::TypeVar(..) => result.push(ann.clone()),
-        TypeAnnotation::Virtual(ann) | TypeAnnotation::List(ann) => {
+        TypeAnnotation::Virtual(ann) => {
            result.extend(get_type_var_contained_in_type_annotation(ann.as_ref()));
        }
        TypeAnnotation::CustomClass { params, .. } => {
@ -605,8 +576,7 @@ pub fn check_overload_type_annotation_compatible(

            a == b
        }
-        (TypeAnnotation::Virtual(a), TypeAnnotation::Virtual(b))
-        | (TypeAnnotation::List(a), TypeAnnotation::List(b)) => {
+        (TypeAnnotation::Virtual(a), TypeAnnotation::Virtual(b)) => {
            check_overload_type_annotation_compatible(a.as_ref(), b.as_ref(), unifier)
        }

--- a/nac3core/src/typecheck/function_check.rs
+++ b/nac3core/src/typecheck/function_check.rs
@ -1,7 +1,7 @@
-use crate::typecheck::typedef::TypeEnum;
+use crate::toplevel::helper::PrimDef;

 use super::type_inferencer::Inferencer;
-use super::typedef::Type;
+use super::typedef::{Type, TypeEnum};
 use nac3parser::ast::{
    self, Constant, Expr, ExprKind,
    Operator::{LShift, RShift},
@ -69,6 +69,7 @@ impl<'a> Inferencer<'a> {
        // there are some cases where the custom field is None
        if let Some(ty) = &expr.custom {
            if !matches!(&expr.node, ExprKind::Constant { value: Constant::Ellipsis, .. })
+                && !ty.obj_id(self.unifier).is_some_and(|id| id == PrimDef::List.id())
                && !self.unifier.is_concrete(*ty, &self.function_data.bound_variables)
            {
                return Err(HashSet::from([format!(
--- a/nac3core/src/typecheck/magic_methods.rs
+++ b/nac3core/src/typecheck/magic_methods.rs
@ -5,7 +5,7 @@ use crate::typecheck::{
    type_inferencer::*,
    typedef::{FunSignature, FuncArg, Type, TypeEnum, Unifier, VarMap},
 };
-use itertools::Itertools;
+use itertools::{iproduct, Itertools};
 use nac3parser::ast::StrRef;
 use nac3parser::ast::{Cmpop, Operator, Unaryop};
 use std::cmp::max;
@ -13,67 +13,138 @@ use std::collections::HashMap;
 use std::rc::Rc;
 use strum::IntoEnumIterator;

-#[must_use]
-pub fn binop_name(op: Operator) -> &'static str {
-    match op {
-        Operator::Add => "__add__",
-        Operator::Sub => "__sub__",
-        Operator::Div => "__truediv__",
-        Operator::Mod => "__mod__",
-        Operator::Mult => "__mul__",
-        Operator::Pow => "__pow__",
-        Operator::BitOr => "__or__",
-        Operator::BitXor => "__xor__",
-        Operator::BitAnd => "__and__",
-        Operator::LShift => "__lshift__",
-        Operator::RShift => "__rshift__",
-        Operator::FloorDiv => "__floordiv__",
-        Operator::MatMult => "__matmul__",
+/// The variant of a binary operator.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum BinopVariant {
+    /// The normal variant.
+    /// For addition, it would be `+`.
+    Normal,
+    /// The "Augmented Assigning Operator" variant.
+    /// For addition, it would be `+=`.
+    AugAssign,
+}
+
+/// A binary operator with its variant.
+#[derive(Debug, Clone, Copy)]
+pub struct Binop {
+    /// The base [`Operator`] of this binary operator.
+    pub base: Operator,
+    /// The variant of this binary operator.
+    pub variant: BinopVariant,
+}
+
+impl Binop {
+    /// Make a [`Binop`] of the normal variant from an [`Operator`].
+    #[must_use]
+    pub fn normal(base: Operator) -> Self {
+        Binop { base, variant: BinopVariant::Normal }
+    }
+
+    /// Make a [`Binop`] of the aug assign variant from an [`Operator`].
+    #[must_use]
+    pub fn aug_assign(base: Operator) -> Self {
+        Binop { base, variant: BinopVariant::AugAssign }
    }
 }

-#[must_use]
-pub fn binop_assign_name(op: Operator) -> &'static str {
-    match op {
-        Operator::Add => "__iadd__",
-        Operator::Sub => "__isub__",
-        Operator::Div => "__itruediv__",
-        Operator::Mod => "__imod__",
-        Operator::Mult => "__imul__",
-        Operator::Pow => "__ipow__",
-        Operator::BitOr => "__ior__",
-        Operator::BitXor => "__ixor__",
-        Operator::BitAnd => "__iand__",
-        Operator::LShift => "__ilshift__",
-        Operator::RShift => "__irshift__",
-        Operator::FloorDiv => "__ifloordiv__",
-        Operator::MatMult => "__imatmul__",
-    }
+/// Details about an operator (unary, binary, etc...) in Python
+#[derive(Debug, Clone, Copy)]
+pub struct OpInfo {
+    /// The method name of the binary operator.
+    /// For addition, this would be `__add__`, and `__iadd__` if
+    /// it is the augmented assigning variant.
+    pub method_name: &'static str,
+    /// The symbol of the binary operator.
+    /// For addition, this would be `+`, and `+=` if
+    /// it is the augmented assigning variant.
+    pub symbol: &'static str,
 }

-#[must_use]
-pub fn unaryop_name(op: Unaryop) -> &'static str {
-    match op {
-        Unaryop::UAdd => "__pos__",
-        Unaryop::USub => "__neg__",
-        Unaryop::Not => "__not__",
-        Unaryop::Invert => "__inv__",
-    }
+/// Helper macro to conveniently build an [`OpInfo`].
+///
+/// Example usage: `make_info("add", "+")` generates `OpInfo { name: "__add__", symbol: "+" }`
+macro_rules! make_op_info {
+    ($name:expr, $symbol:expr) => {
+        OpInfo { method_name: concat!("__", $name, "__"), symbol: $symbol }
+    };
 }

-#[must_use]
-pub fn comparison_name(op: Cmpop) -> Option<&'static str> {
+pub trait HasOpInfo {
+    fn op_info(&self) -> OpInfo;
+}
+
+fn try_get_cmpop_info(op: Cmpop) -> Option<OpInfo> {
    match op {
-        Cmpop::Lt => Some("__lt__"),
-        Cmpop::LtE => Some("__le__"),
-        Cmpop::Gt => Some("__gt__"),
-        Cmpop::GtE => Some("__ge__"),
-        Cmpop::Eq => Some("__eq__"),
-        Cmpop::NotEq => Some("__ne__"),
+        Cmpop::Lt => Some(make_op_info!("lt", "<")),
+        Cmpop::LtE => Some(make_op_info!("le", "<=")),
+        Cmpop::Gt => Some(make_op_info!("gt", ">")),
+        Cmpop::GtE => Some(make_op_info!("ge", ">=")),
+        Cmpop::Eq => Some(make_op_info!("eq", "==")),
+        Cmpop::NotEq => Some(make_op_info!("ne", "!=")),
        _ => None,
    }
 }

+impl OpInfo {
+    #[must_use]
+    pub fn supports_cmpop(op: Cmpop) -> bool {
+        try_get_cmpop_info(op).is_some()
+    }
+}
+
+impl HasOpInfo for Cmpop {
+    fn op_info(&self) -> OpInfo {
+        try_get_cmpop_info(*self).expect("{self:?} is not supported")
+    }
+}
+
+impl HasOpInfo for Binop {
+    fn op_info(&self) -> OpInfo {
+        // Helper macro to generate both the normal variant [`OpInfo`] and the
+        // augmented assigning variant [`OpInfo`] for a binary operator conveniently.
+        macro_rules! info {
+            ($name:literal, $symbol:literal) => {
+                (
+                    make_op_info!($name, $symbol),
+                    make_op_info!(concat!("i", $name), concat!($symbol, "=")),
+                )
+            };
+        }
+
+        let (normal_variant, aug_assign_variant) = match self.base {
+            Operator::Add => info!("add", "+"),
+            Operator::Sub => info!("sub", "-"),
+            Operator::Div => info!("truediv", "/"),
+            Operator::Mod => info!("mod", "%"),
+            Operator::Mult => info!("mul", "*"),
+            Operator::Pow => info!("pow", "**"),
+            Operator::BitOr => info!("or", "|"),
+            Operator::BitXor => info!("xor", "^"),
+            Operator::BitAnd => info!("and", "&"),
+            Operator::LShift => info!("lshift", "<<"),
+            Operator::RShift => info!("rshift", ">>"),
+            Operator::FloorDiv => info!("floordiv", "//"),
+            Operator::MatMult => info!("matmul", "@"),
+        };
+
+        match self.variant {
+            BinopVariant::Normal => normal_variant,
+            BinopVariant::AugAssign => aug_assign_variant,
+        }
+    }
+}
+
+impl HasOpInfo for Unaryop {
+    fn op_info(&self) -> OpInfo {
+        match self {
+            Unaryop::UAdd => make_op_info!("pos", "+"),
+            Unaryop::USub => make_op_info!("neg", "-"),
+            Unaryop::Not => make_op_info!("not", "not"), // i.e., `not False`, so the symbol is just `not`.
+            Unaryop::Invert => make_op_info!("inv", "~"),
+        }
+    }
+}
+
 pub(super) fn with_fields<F>(unifier: &mut Unifier, ty: Type, f: F)
 where
    F: FnOnce(&mut Unifier, &mut HashMap<StrRef, (Type, bool)>),
@ -115,23 +186,9 @@ pub fn impl_binop(

        let ret_ty = ret_ty.unwrap_or_else(|| unifier.get_fresh_var(None, None).ty);

-        for op in ops {
-            fields.insert(binop_name(*op).into(), {
-                (
-                    unifier.add_ty(TypeEnum::TFunc(FunSignature {
-                        ret: ret_ty,
-                        vars: function_vars.clone(),
-                        args: vec![FuncArg {
-                            ty: other_ty,
-                            default_value: None,
-                            name: "other".into(),
-                        }],
-                    })),
-                    false,
-                )
-            });
-
-            fields.insert(binop_assign_name(*op).into(), {
+        for (base_op, variant) in iproduct!(ops, [BinopVariant::Normal, BinopVariant::AugAssign]) {
+            let op = Binop { base: *base_op, variant };
+            fields.insert(op.op_info().method_name.into(), {
                (
                    unifier.add_ty(TypeEnum::TFunc(FunSignature {
                        ret: ret_ty,
@ -155,7 +212,7 @@ pub fn impl_unaryop(unifier: &mut Unifier, ty: Type, ret_ty: Option<Type>, ops:

        for op in ops {
            fields.insert(
-                unaryop_name(*op).into(),
+                op.op_info().method_name.into(),
                (
                    unifier.add_ty(TypeEnum::TFunc(FunSignature {
                        ret: ret_ty,
@ -195,7 +252,7 @@ pub fn impl_cmpop(

        for op in ops {
            fields.insert(
-                comparison_name(*op).unwrap().into(),
+                op.op_info().method_name.into(),
                (
                    unifier.add_ty(TypeEnum::TFunc(FunSignature {
                        ret: ret_ty,
@ -429,12 +486,29 @@ pub fn typeof_binop(
    lhs: Type,
    rhs: Type,
 ) -> Result<Option<Type>, String> {
+    let op = Binop { base: op, variant: BinopVariant::Normal };
+
+    let is_left_list = lhs.obj_id(unifier).is_some_and(|id| id == PrimDef::List.id());
+    let is_right_list = rhs.obj_id(unifier).is_some_and(|id| id == PrimDef::List.id());
    let is_left_ndarray = lhs.obj_id(unifier).is_some_and(|id| id == PrimDef::NDArray.id());
    let is_right_ndarray = rhs.obj_id(unifier).is_some_and(|id| id == PrimDef::NDArray.id());

-    Ok(Some(match op {
+    Ok(Some(match op.base {
        Operator::Add | Operator::Sub | Operator::Mult | Operator::Mod | Operator::FloorDiv => {
-            if is_left_ndarray || is_right_ndarray {
+            if is_left_list || is_right_list {
+                if ![Operator::Add, Operator::Mult].contains(&op.base) {
+                    return Err(format!(
+                        "Binary operator {} not supported for list",
+                        op.op_info().symbol
+                    ));
+                }
+
+                if is_left_list {
+                    lhs
+                } else {
+                    rhs
+                }
+            } else if is_left_ndarray || is_right_ndarray {
                typeof_ndarray_broadcast(unifier, primitives, lhs, rhs)?
            } else if unifier.unioned(lhs, rhs) {
                lhs
@ -604,6 +678,7 @@ pub fn set_primitives_magic_methods(store: &PrimitiveStore, unifier: &mut Unifie
        bool: bool_t,
        uint32: uint32_t,
        uint64: uint64_t,
+        list: list_t,
        ndarray: ndarray_t,
        ..
    } = *store;
@ -648,6 +723,11 @@ pub fn set_primitives_magic_methods(store: &PrimitiveStore, unifier: &mut Unifie
    impl_sign(unifier, store, bool_t, Some(int32_t));
    impl_eq(unifier, store, bool_t, &[bool_t, ndarray_bool_t], None);

+    /* list ======== */
+    impl_binop(unifier, store, list_t, &[list_t], Some(list_t), &[Operator::Add]);
+    impl_binop(unifier, store, list_t, &[int32_t, int64_t], Some(list_t), &[Operator::Mult]);
+    impl_cmpop(unifier, store, list_t, &[list_t], &[Cmpop::Eq, Cmpop::NotEq], Some(bool_t));
+
    /* ndarray ===== */
    let ndarray_usized_ndims_tvar =
        unifier.get_fresh_const_generic_var(size_t, Some("ndarray_ndims".into()), None);
--- a/nac3core/src/typecheck/type_error.rs
+++ b/nac3core/src/typecheck/type_error.rs
@ -1,24 +1,46 @@
 use std::collections::HashMap;
 use std::fmt::Display;

-use crate::typecheck::typedef::TypeEnum;
+use crate::typecheck::{magic_methods::HasOpInfo, typedef::TypeEnum};

-use super::typedef::{RecordKey, Type, Unifier};
-use nac3parser::ast::{Location, StrRef};
+use super::{
+    magic_methods::Binop,
+    typedef::{RecordKey, Type, Unifier},
+};
+use itertools::Itertools;
+use nac3parser::ast::{Cmpop, Location, StrRef};

 #[derive(Debug, Clone)]
 pub enum TypeErrorKind {
-    TooManyArguments {
-        expected: usize,
-        got: usize,
+    GotMultipleValues {
+        name: StrRef,
+    },
+    TooManyArguments {
+        expected_min_count: usize,
+        expected_max_count: usize,
+        got_count: usize,
+    },
+    MissingArgs {
+        missing_arg_names: Vec<StrRef>,
    },
-    MissingArgs(String),
    UnknownArgName(StrRef),
    IncorrectArgType {
        name: StrRef,
        expected: Type,
        got: Type,
    },
+    UnsupportedBinaryOpTypes {
+        operator: Binop,
+        lhs_type: Type,
+        rhs_type: Type,
+        expected_rhs_type: Type,
+    },
+    UnsupportedComparsionOpTypes {
+        operator: Cmpop,
+        lhs_type: Type,
+        rhs_type: Type,
+        expected_rhs_type: Type,
+    },
    FieldUnificationError {
        field: RecordKey,
        types: (Type, Type),
@ -34,6 +56,7 @@ pub enum TypeErrorKind {
    },
    RequiresTypeAnn,
    PolymorphicFunctionPointer,
+    NoSuchAttribute(RecordKey, Type),
 }

 #[derive(Debug, Clone)]
@ -77,19 +100,49 @@ impl<'a> Display for DisplayTypeError<'a> {
        use TypeErrorKind::*;
        let mut notes = Some(HashMap::new());
        match &self.err.kind {
-            TooManyArguments { expected, got } => {
-                write!(f, "Too many arguments. Expected {expected} but got {got}")
+            GotMultipleValues { name } => {
+                write!(f, "For multiple values for parameter {name}")
            }
-            MissingArgs(args) => {
+            TooManyArguments { expected_min_count, expected_max_count, got_count } => {
+                debug_assert!(expected_min_count <= expected_max_count);
+                if expected_min_count == expected_max_count {
+                    let expected_count = expected_min_count; // or expected_max_count
+                    write!(f, "Too many arguments. Expected {expected_count} but got {got_count}")
+                } else {
+                    write!(f, "Too many arguments. Expected {expected_min_count} to {expected_max_count} arguments but got {got_count}")
+                }
+            }
+            MissingArgs { missing_arg_names } => {
+                let args = missing_arg_names.iter().join(", ");
                write!(f, "Missing arguments: {args}")
            }
+            UnsupportedBinaryOpTypes { operator, lhs_type, rhs_type, expected_rhs_type } => {
+                let op_symbol = operator.op_info().symbol;
+
+                let lhs_type_str = self.unifier.stringify_with_notes(*lhs_type, &mut notes);
+                let rhs_type_str = self.unifier.stringify_with_notes(*rhs_type, &mut notes);
+                let expected_rhs_type_str =
+                    self.unifier.stringify_with_notes(*expected_rhs_type, &mut notes);
+
+                write!(f, "Unsupported operand type(s) for {op_symbol}: '{lhs_type_str}' and '{rhs_type_str}' (right operand should have type {expected_rhs_type_str})")
+            }
+            UnsupportedComparsionOpTypes { operator, lhs_type, rhs_type, expected_rhs_type } => {
+                let op_symbol = operator.op_info().symbol;
+
+                let lhs_type_str = self.unifier.stringify_with_notes(*lhs_type, &mut notes);
+                let rhs_type_str = self.unifier.stringify_with_notes(*rhs_type, &mut notes);
+                let expected_rhs_type_str =
+                    self.unifier.stringify_with_notes(*expected_rhs_type, &mut notes);
+
+                write!(f, "'{op_symbol}' not supported between instances of '{lhs_type_str}' and '{rhs_type_str}' (right operand should have type {expected_rhs_type_str})")
+            }
            UnknownArgName(name) => {
                write!(f, "Unknown argument name: {name}")
            }
            IncorrectArgType { name, expected, got } => {
                let expected = self.unifier.stringify_with_notes(*expected, &mut notes);
                let got = self.unifier.stringify_with_notes(*got, &mut notes);
-                write!(f, "Incorrect argument type for {name}. Expected {expected}, but got {got}")
+                write!(f, "Incorrect argument type for parameter {name}. Expected {expected}, but got {got}")
            }
            FieldUnificationError { field, types, loc } => {
                let lhs = self.unifier.stringify_with_notes(types.0, &mut notes);
@ -156,6 +209,10 @@ impl<'a> Display for DisplayTypeError<'a> {
                let t = self.unifier.stringify_with_notes(*t, &mut notes);
                write!(f, "`{t}::{name}` field/method does not exist")
            }
+            NoSuchAttribute(name, t) => {
+                let t = self.unifier.stringify_with_notes(*t, &mut notes);
+                write!(f, "`{t}::{name}` is not a class attribute")
+            }
            TupleIndexOutOfBounds { index, len } => {
                write!(
                    f,
--- a/nac3core/src/typecheck/type_inferencer/mod.rs
+++ b/nac3core/src/typecheck/type_inferencer/mod.rs
@ -4,14 +4,20 @@ use std::iter::once;
 use std::ops::Not;
 use std::{cell::RefCell, sync::Arc};

-use super::typedef::{Call, FunSignature, FuncArg, RecordField, Type, TypeEnum, Unifier, VarMap};
-use super::{magic_methods::*, type_error::TypeError, typedef::CallId};
+use super::{
+    magic_methods::*,
+    type_error::{TypeError, TypeErrorKind},
+    typedef::{
+        into_var_map, iter_type_vars, Call, CallId, FunSignature, FuncArg, OperatorInfo,
+        RecordField, RecordKey, Type, TypeEnum, TypeVar, Unifier, VarMap,
+    },
+};
 use crate::{
    symbol_resolver::{SymbolResolver, SymbolValue},
    toplevel::{
        helper::{arraylike_flatten_element_type, arraylike_get_ndims, PrimDef},
        numpy::{make_ndarray_ty, unpack_ndarray_var_tys},
-        TopLevelContext,
+        TopLevelContext, TopLevelDef,
    },
 };
 use itertools::{izip, Itertools};
@ -49,6 +55,7 @@ pub struct PrimitiveStore {
    pub str: Type,
    pub exception: Type,
    pub option: Type,
+    pub list: Type,
    pub ndarray: Type,
    pub size_t: u32,
 }
@ -106,6 +113,14 @@ fn report_error<T>(msg: &str, location: Location) -> Result<T, HashSet<String>>
    Err(HashSet::from([format!("{msg} at {location}")]))
 }

+fn report_type_error<T>(
+    kind: TypeErrorKind,
+    loc: Option<Location>,
+    unifier: &Unifier,
+) -> Result<T, HashSet<String>> {
+    Err(HashSet::from([TypeError::new(kind, loc).to_display(unifier).to_string()]))
+}
+
 impl<'a> Fold<()> for Inferencer<'a> {
    type TargetU = Option<Type>;
    type Error = HashSet<String>;
@ -241,13 +256,32 @@ impl<'a> Fold<()> for Inferencer<'a> {
                    self.unify(self.primitives.int32, target.custom.unwrap(), &target.location)?;
                } else {
                    let list_like_ty = match &*self.unifier.get_ty(iter.custom.unwrap()) {
-                        TypeEnum::TList { .. } => {
-                            self.unifier.add_ty(TypeEnum::TList { ty: target.custom.unwrap() })
+                        TypeEnum::TObj { obj_id, params, .. } if *obj_id == PrimDef::List.id() => {
+                            let list_tvar = iter_type_vars(params).nth(0).unwrap();
+                            self.unifier
+                                .subst(
+                                    self.primitives.list,
+                                    &into_var_map([TypeVar {
+                                        id: list_tvar.id,
+                                        ty: target.custom.unwrap(),
+                                    }]),
+                                )
+                                .unwrap()
                        }
                        TypeEnum::TObj { obj_id, .. } if *obj_id == PrimDef::NDArray.id() => {
                            todo!()
                        }
-                        _ => unreachable!(),
+                        _ => {
+                            // User is attempting to use a for loop to iterate
+                            // over a value of an unsupported type.
+
+                            let iter_ty = iter.custom.unwrap();
+                            let iter_ty_str = self.unifier.stringify(iter_ty);
+                            return report_error(
+                                format!("'{iter_ty_str}' object is not iterable").as_str(),
+                                iter.location,
+                            );
+                        }
                    };
                    self.unify(list_like_ty, iter.custom.unwrap(), &iter.location)?;
                }
@ -465,7 +499,8 @@ impl<'a> Fold<()> for Inferencer<'a> {
                (None, None) => {}
            },
            ast::StmtKind::AugAssign { target, op, value, .. } => {
-                let res_ty = self.infer_bin_ops(stmt.location, target, *op, value, true)?;
+                let res_ty =
+                    self.infer_bin_ops(stmt.location, target, Binop::aug_assign(*op), value)?;
                self.unify(res_ty, target.custom.unwrap(), &stmt.location)?;
            }
            ast::StmtKind::Assert { test, msg, .. } => {
@ -547,7 +582,7 @@ impl<'a> Fold<()> for Inferencer<'a> {
            }
            ExprKind::BoolOp { values, .. } => Some(self.infer_bool_ops(values)?),
            ExprKind::BinOp { left, op, right } => {
-                Some(self.infer_bin_ops(expr.location, left, *op, right, false)?)
+                Some(self.infer_bin_ops(expr.location, left, Binop::normal(*op), right)?)
            }
            ExprKind::UnaryOp { op, operand } => {
                Some(self.infer_unary_ops(expr.location, *op, operand)?)
@ -614,6 +649,7 @@ impl<'a> Inferencer<'a> {
        obj: Type,
        params: Vec<Type>,
        ret: Option<Type>,
+        operator_info: Option<OperatorInfo>,
    ) -> InferenceResult {
        if let TypeEnum::TObj { params: class_params, fields, .. } = &*self.unifier.get_ty(obj) {
            if class_params.is_empty() {
@ -627,6 +663,7 @@ impl<'a> Inferencer<'a> {
                                ret: sign.ret,
                                fun: RefCell::new(None),
                                loc: Some(location),
+                                operator_info,
                            };
                            if let Some(ret) = ret {
                                self.unifier
@ -641,14 +678,7 @@ impl<'a> Inferencer<'a> {
                                    })
                                    .unwrap();
                            }
-                            let required: Vec<_> = sign
-                                .args
-                                .iter()
-                                .filter(|v| v.default_value.is_none())
-                                .map(|v| v.name)
-                                .rev()
-                                .collect();
-                            self.unifier.unify_call(&call, ty, sign, &required).map_err(|e| {
+                            self.unifier.unify_call(&call, ty, sign).map_err(|e| {
                                HashSet::from([e
                                    .at(Some(location))
                                    .to_display(self.unifier)
@ -668,6 +698,7 @@ impl<'a> Inferencer<'a> {
            ret,
            fun: RefCell::new(None),
            loc: Some(location),
+            operator_info,
        });
        self.calls.insert(location.into(), call);
        let call = self.unifier.add_ty(TypeEnum::TCall(vec![call]));
@ -760,6 +791,16 @@ impl<'a> Inferencer<'a> {
                generators[0].target.location,
            );
        }
+
+        let list_tvar = if let TypeEnum::TObj { obj_id, params, .. } =
+            &*self.unifier.get_ty_immutable(self.primitives.list)
+        {
+            assert_eq!(*obj_id, PrimDef::List.id());
+            iter_type_vars(params).nth(0).unwrap()
+        } else {
+            unreachable!()
+        };
+
        let variable_mapping = self.variable_mapping.clone();
        let defined_identifiers = self.defined_identifiers.clone();
        let mut new_context = Inferencer {
@ -788,7 +829,13 @@ impl<'a> Inferencer<'a> {
                &target.location,
            )?;
        } else {
-            let list = new_context.unifier.add_ty(TypeEnum::TList { ty: target.custom.unwrap() });
+            let list = new_context
+                .unifier
+                .subst(
+                    self.primitives.list,
+                    &into_var_map([TypeVar { id: list_tvar.id, ty: target.custom.unwrap() }]),
+                )
+                .unwrap();
            new_context.unify(iter.custom.unwrap(), list, &iter.location)?;
        }
        let ifs: Vec<_> = generator
@ -805,9 +852,16 @@ impl<'a> Inferencer<'a> {
            new_context.unify(v.custom.unwrap(), new_context.primitives.bool, &v.location)?;
        }

+        let custom = new_context
+            .unifier
+            .subst(
+                self.primitives.list,
+                &into_var_map([TypeVar { id: list_tvar.id, ty: elt.custom.unwrap() }]),
+            )
+            .unwrap();
        Ok(Located {
            location,
-            custom: Some(new_context.unifier.add_ty(TypeEnum::TList { ty: elt.custom.unwrap() })),
+            custom: Some(custom),
            node: ExprKind::ListComp {
                elt: Box::new(elt),
                generators: vec![Comprehension {
@ -820,6 +874,151 @@ impl<'a> Inferencer<'a> {
        })
    }

+    /// Fold an ndarray `shape` argument. This function aims to fold `shape` arguments like that of
+    /// <https://numpy.org/doc/stable/reference/generated/numpy.zeros.html> (for `np_zeros`).
+    ///
+    /// Arguments:
+    ///   * `id` - The name of the function of the function call this `shape` argument is in. Used for error reporting.
+    ///   * `arg_index` - The position (0-based) of this argument in the function call. Used for error reporting.
+    ///   * `shape_expr` - [`Located<ExprKind>`] of the input argument.
+    ///
+    /// On success, it returns a tuple of
+    ///   1) the `ndims` value inferred from the input `shape`,
+    ///   2) and the elaborated expression. Like what other fold functions of [`Inferencer`] would normally return.
+    fn fold_numpy_function_call_shape_argument(
+        &mut self,
+        id: StrRef,
+        arg_index: usize,
+        shape_expr: Located<ExprKind>,
+    ) -> Result<(u64, ast::Expr<Option<Type>>), HashSet<String>> {
+        /*
+            ### Further explanation
+
+            As said, this function aims to fold `shape` arguments, but this is *not* trivial.
+            The root of the issue is that `nac3core` has to deduce the `ndims`
+            of the created (for in the case of `np_zeros`) ndarray statically - i.e., during inference time.
+
+            There are three types of valid input to `shape`:
+              1. A python `List` (all `int32s`);   e.g., `np_zeros([600, 800, 3])`
+              2. A python `Tuple` (all `int32s`);  e.g., `np_zeros((600, 800, 3))`
+              3. An `int32`; e.g., `np_zeros(256)` - this is functionally equivalent to `np_zeros([256])`
+
+            For 2. and 3., `ndims` can be deduce immediately from the inferred type of the input:
+              - For 2. `ndims` is simply the number of elements found in [`TypeEnum::TTuple`] after typechecking the `shape` argument.
+              - For 3. `ndims` is simply 1.
+
+            For 1., `ndims` is supposedly the length of the input list. However, the length of the input list
+            is a runtime property. Therefore (as a hack) we resort to analyzing the argument expression [`ExprKind::List`]
+            itself to extract the input list length statically.
+
+            This implies that the user could only write:
+
+            ```python
+            my_rgba_image = np_zeros([600, 800, 4])
+            # the shape argument is directly written as a list literal.
+            # and `nac3core` could therefore tell that ndims is `3` by
+            # looking at the raw AST expression itself.
+            ```
+
+            But not:
+
+            ```python
+            my_image_dimension = [600, 800, 4]
+            mystery_function_that_mutates_my_list(my_image_dimension)
+            my_image = np_zeros(my_image_dimension)
+            # what is the length now? what is `ndims`?
+
+            # it is *basically impossible* to generally determine the
+            # length of `my_image_dimension` statically for `ndims`!!
+            ```
+        */
+
+        // Fold `shape`
+        let shape = self.fold_expr(shape_expr)?;
+        let shape_ty = shape.custom.unwrap(); // The inferred type of `shape`
+
+        // Check `shape_ty` to see if its a list of int32s, a tuple of int32s, or just int32.
+        // Otherwise throw an error as that would mean the user wrote an ill-typed `shape_expr`.
+        //
+        // Here, we also take the opportunity to deduce `ndims` statically.
+        let shape_ty_enum = &*self.unifier.get_ty(shape_ty);
+        let ndims = match shape_ty_enum {
+            TypeEnum::TObj { obj_id, params, .. } if *obj_id == PrimDef::List.id() => {
+                // Handle 1. A list of int32s
+
+                let ty = iter_type_vars(params).nth(0).unwrap().ty;
+
+                // Typecheck
+                self.unifier.unify(ty, self.primitives.int32).map_err(|err| {
+                    HashSet::from([err
+                        .at(Some(shape.location))
+                        .to_display(self.unifier)
+                        .to_string()])
+                })?;
+
+                // Special handling for (1. A python `List` (all `int32s`)).
+                // Read the doc above this function to see what is going on here.
+                if let ExprKind::List { elts, .. } = &shape.node {
+                    // The user wrote a List literal as the input argument
+                    elts.len() as u64
+                } else {
+                    // This means the user is passing an expression of type `List`,
+                    // but it is done so indirectly (like putting a variable referencing a `List`)
+                    // rather than writing a List literal. We need to report an error.
+                    return Err(HashSet::from([
+                        format!(
+                            "Expected list literal, tuple, or int32 for argument {arg_num} of {id} at {location}. Input argument is of type list but not a list literal.",
+                            arg_num = arg_index + 1,
+                            location = shape.location
+                        )
+                    ]));
+                }
+            }
+            TypeEnum::TTuple { ty: tuple_element_types } => {
+                // Handle 2. A tuple of int32s
+
+                // Typecheck
+                // The expected type is just the tuple but with all its elements being int32.
+                let expected_ty = self.unifier.add_ty(TypeEnum::TTuple {
+                    ty: tuple_element_types.iter().map(|_| self.primitives.int32).collect_vec(),
+                });
+                self.unifier.unify(shape_ty, expected_ty).map_err(|err| {
+                    HashSet::from([err
+                        .at(Some(shape.location))
+                        .to_display(self.unifier)
+                        .to_string()])
+                })?;
+
+                // `ndims` can be deduced statically from the inferred Tuple type.
+                tuple_element_types.len() as u64
+            }
+            TypeEnum::TObj { obj_id, .. }
+                if *obj_id == self.primitives.int32.obj_id(self.unifier).unwrap() =>
+            {
+                // Handle 3. An int32 (generalized as [`TypeEnum::TObj`])
+
+                // Deduce `ndims`
+                1
+            }
+            _ => {
+                // The user wrote an ill-typed `shape_expr`,
+                // so throw an error.
+                let shape_ty_str = self.unifier.stringify(shape_ty);
+                return report_error(
+                    format!(
+                        "Expected list literal, tuple, or int32 for argument {arg_num} of {id}, got {shape_expr_name} of type {shape_ty_str}",
+                        arg_num = arg_index + 1,
+                        shape_expr_name = shape.node.name(),
+                    )
+                    .as_str(),
+                    shape.location,
+                );
+            }
+        };
+
+        Ok((ndims, shape))
+    }
+
    /// Tries to fold a special call. Returns [`Some`] if the call expression `func` is a special call, otherwise
    /// returns [`None`].
    fn try_fold_special_call(
@ -1147,25 +1346,15 @@ impl<'a> Inferencer<'a> {
            }));
        }

-        // 1-argument ndarray n-dimensional creation functions
+        // 1-argument ndarray n-dimensional factory functions
        if ["np_ndarray".into(), "np_empty".into(), "np_zeros".into(), "np_ones".into()]
            .contains(id)
            && args.len() == 1
        {
-            let ExprKind::List { elts, .. } = &args[0].node else {
-                return report_error(
-                    format!(
-                        "Expected List literal for first argument of {id}, got {}",
-                        args[0].node.name()
-                    )
-                    .as_str(),
-                    args[0].location,
-                );
-            };
+            let shape_expr = args.remove(0);
+            let (ndims, shape) =
+                self.fold_numpy_function_call_shape_argument(*id, 0, shape_expr)?; // Special handling for `shape`

-            let ndims = elts.len() as u64;
-
-            let arg0 = self.fold_expr(args.remove(0))?;
            let ndims = self.unifier.get_fresh_literal(vec![SymbolValue::U64(ndims)], None);
            let ret = make_ndarray_ty(
                self.unifier,
@ -1176,7 +1365,7 @@ impl<'a> Inferencer<'a> {
            let custom = self.unifier.add_ty(TypeEnum::TFunc(FunSignature {
                args: vec![FuncArg {
                    name: "shape".into(),
-                    ty: arg0.custom.unwrap(),
+                    ty: shape.custom.unwrap(),
                    default_value: None,
                }],
                ret,
@ -1192,7 +1381,7 @@ impl<'a> Inferencer<'a> {
                        location: func.location,
                        node: ExprKind::Name { id: *id, ctx: *ctx },
                    }),
-                    args: vec![arg0],
+                    args: vec![shape],
                    keywords: vec![],
                },
            }));
@ -1345,17 +1534,11 @@ impl<'a> Inferencer<'a> {
                    fun: RefCell::new(None),
                    ret: sign.ret,
                    loc: Some(location),
+                    operator_info: None,
                };
-                let required: Vec<_> = sign
-                    .args
-                    .iter()
-                    .filter(|v| v.default_value.is_none())
-                    .map(|v| v.name)
-                    .rev()
-                    .collect();
-                self.unifier.unify_call(&call, func.custom.unwrap(), sign, &required).map_err(
-                    |e| HashSet::from([e.at(Some(location)).to_display(self.unifier).to_string()]),
-                )?;
+                self.unifier.unify_call(&call, func.custom.unwrap(), sign).map_err(|e| {
+                    HashSet::from([e.at(Some(location)).to_display(self.unifier).to_string()])
+                })?;
                return Ok(Located {
                    location,
                    custom: Some(sign.ret),
@ -1374,6 +1557,7 @@ impl<'a> Inferencer<'a> {
            fun: RefCell::new(None),
            ret,
            loc: Some(location),
+            operator_info: None,
        });
        self.calls.insert(location.into(), call);
        let call = self.unifier.add_ty(TypeEnum::TCall(vec![call]));
@ -1432,7 +1616,19 @@ impl<'a> Inferencer<'a> {
        for t in elts {
            self.unify(ty, t.custom.unwrap(), &t.location)?;
        }
-        Ok(self.unifier.add_ty(TypeEnum::TList { ty }))
+        let list_tvar = if let TypeEnum::TObj { obj_id, params, .. } =
+            &*self.unifier.get_ty_immutable(self.primitives.list)
+        {
+            assert_eq!(*obj_id, PrimDef::List.id());
+            iter_type_vars(params).nth(0).unwrap()
+        } else {
+            unreachable!()
+        };
+        let list = self
+            .unifier
+            .subst(self.primitives.list, &into_var_map([TypeVar { id: list_tvar.id, ty }]))
+            .unwrap();
+        Ok(list)
    }

    #[allow(clippy::unnecessary_wraps)]
@ -1441,6 +1637,24 @@ impl<'a> Inferencer<'a> {
        Ok(self.unifier.add_ty(TypeEnum::TTuple { ty }))
    }

+    /// Checks for non-class attributes
+    fn infer_general_attribute(
+        &mut self,
+        value: &ast::Expr<Option<Type>>,
+        attr: StrRef,
+        ctx: ExprContext,
+    ) -> InferenceResult {
+        let attr_ty = self.unifier.get_dummy_var().ty;
+        let fields = once((
+            attr.into(),
+            RecordField::new(attr_ty, ctx == ExprContext::Store, Some(value.location)),
+        ))
+        .collect();
+        let record = self.unifier.add_record(fields);
+        self.constrain(value.custom.unwrap(), record, &value.location)?;
+        Ok(attr_ty)
+    }
+
    fn infer_attribute(
        &mut self,
        value: &ast::Expr<Option<Type>>,
@ -1448,31 +1662,72 @@ impl<'a> Inferencer<'a> {
        ctx: ExprContext,
    ) -> InferenceResult {
        let ty = value.custom.unwrap();
-        if let TypeEnum::TObj { fields, .. } = &*self.unifier.get_ty(ty) {
+        if let TypeEnum::TObj { obj_id, fields, .. } = &*self.unifier.get_ty(ty) {
            // just a fast path
            match (fields.get(&attr), ctx == ExprContext::Store) {
                (Some((ty, true)), _) | (Some((ty, false)), false) => Ok(*ty),
-                (Some((_, false)), true) => {
-                    report_error(&format!("Field `{attr}` is immutable"), value.location)
-                }
-                (None, _) => {
-                    let t = self.unifier.stringify(ty);
-                    report_error(
-                        &format!("`{t}::{attr}` field/method does not exist"),
-                        value.location,
-                    )
+                (Some((ty, false)), true) => report_type_error(
+                    TypeErrorKind::MutationError(RecordKey::Str(attr), *ty),
+                    Some(value.location),
+                    self.unifier,
+                ),
+                (None, mutable) => {
+                    // Check whether it is a class attribute
+                    let defs = self.top_level.definitions.read();
+                    let result = {
+                        if let TopLevelDef::Class { attributes, .. } = &*defs[obj_id.0].read() {
+                            attributes.iter().find_map(|f| {
+                                if f.0 == attr {
+                                    return Some(f.1);
+                                }
+                                None
+                            })
+                        } else {
+                            None
+                        }
+                    };
+                    match result {
+                        Some(res) if !mutable => Ok(res),
+                        Some(_) => report_error(
+                            &format!("Class Attribute `{attr}` is immutable"),
+                            value.location,
+                        ),
+                        None => report_type_error(
+                            TypeErrorKind::NoSuchField(RecordKey::Str(attr), ty),
+                            Some(value.location),
+                            self.unifier,
+                        ),
+                    }
                }
            }
+        } else if let TypeEnum::TFunc(sign) = &*self.unifier.get_ty(ty) {
+            // Access Class Attributes of classes with __init__ function using Class names e.g. Foo.ATTR1
+            let result = {
+                self.top_level.definitions.read().iter().find_map(|def| {
+                    if let Some(rear_guard) = def.try_read() {
+                        if let TopLevelDef::Class { name, attributes, .. } = &*rear_guard {
+                            if name.to_string() == self.unifier.stringify(sign.ret) {
+                                return attributes.iter().find_map(|f| {
+                                    if f.0 == attr {
+                                        return Some(f.clone().1);
+                                    }
+                                    None
+                                });
+                            }
+                        }
+                    }
+                    None
+                })
+            };
+            match result {
+                Some(f) if ctx != ExprContext::Store => Ok(f),
+                Some(_) => {
+                    report_error(&format!("Class Attribute `{attr}` is immutable"), value.location)
+                }
+                None => self.infer_general_attribute(value, attr, ctx),
+            }
        } else {
-            let attr_ty = self.unifier.get_dummy_var().ty;
-            let fields = once((
-                attr.into(),
-                RecordField::new(attr_ty, ctx == ExprContext::Store, Some(value.location)),
-            ))
-            .collect();
-            let record = self.unifier.add_record(fields);
-            self.constrain(value.custom.unwrap(), record, &value.location)?;
-            Ok(attr_ty)
+            self.infer_general_attribute(value, attr, ctx)
        }
    }

@ -1488,9 +1743,8 @@ impl<'a> Inferencer<'a> {
        &mut self,
        location: Location,
        left: &ast::Expr<Option<Type>>,
-        op: ast::Operator,
+        op: Binop,
        right: &ast::Expr<Option<Type>>,
-        is_aug_assign: bool,
    ) -> InferenceResult {
        let left_ty = left.custom.unwrap();
        let right_ty = right.custom.unwrap();
@ -1498,27 +1752,40 @@ impl<'a> Inferencer<'a> {
        let method = if let TypeEnum::TObj { fields, .. } =
            self.unifier.get_ty_immutable(left_ty).as_ref()
        {
-            let (binop_name, binop_assign_name) =
-                (binop_name(op).into(), binop_assign_name(op).into());
+            let normal_method_name = Binop::normal(op.base).op_info().method_name;
+            let assign_method_name = Binop::aug_assign(op.base).op_info().method_name;
+
            // if is aug_assign, try aug_assign operator first
-            if is_aug_assign && fields.contains_key(&binop_assign_name) {
-                binop_assign_name
+            if op.variant == BinopVariant::AugAssign
+                && fields.contains_key(&assign_method_name.into())
+            {
+                assign_method_name
            } else {
-                binop_name
+                normal_method_name
            }
        } else {
-            binop_name(op).into()
+            op.op_info().method_name
        };

-        let ret = if is_aug_assign {
-            // The type of augmented assignment operator should never change
-            Some(left_ty)
-        } else {
-            typeof_binop(self.unifier, self.primitives, op, left_ty, right_ty)
-                .map_err(|e| HashSet::from([format!("{e} (at {location})")]))?
+        let ret = match op.variant {
+            BinopVariant::Normal => {
+                typeof_binop(self.unifier, self.primitives, op.base, left_ty, right_ty)
+                    .map_err(|e| HashSet::from([format!("{e} (at {location})")]))?
+            }
+            BinopVariant::AugAssign => {
+                // The type of augmented assignment operator should never change
+                Some(left_ty)
+            }
        };

-        self.build_method_call(location, method, left_ty, vec![right_ty], ret)
+        self.build_method_call(
+            location,
+            method.into(),
+            left_ty,
+            vec![right_ty],
+            ret,
+            Some(OperatorInfo::IsBinaryOp { self_type: left.custom.unwrap(), operator: op }),
+        )
    }

    fn infer_unary_ops(
@ -1527,12 +1794,19 @@ impl<'a> Inferencer<'a> {
        op: ast::Unaryop,
        operand: &ast::Expr<Option<Type>>,
    ) -> InferenceResult {
-        let method = unaryop_name(op).into();
+        let method = op.op_info().method_name.into();

        let ret = typeof_unaryop(self.unifier, self.primitives, op, operand.custom.unwrap())
            .map_err(|e| HashSet::from([format!("{e} (at {location})")]))?;

-        self.build_method_call(location, method, operand.custom.unwrap(), vec![], ret)
+        self.build_method_call(
+            location,
+            method,
+            operand.custom.unwrap(),
+            vec![],
+            ret,
+            Some(OperatorInfo::IsUnaryOp { self_type: operand.custom.unwrap(), operator: op }),
+        )
    }

    fn infer_compare(
@ -1557,9 +1831,11 @@ impl<'a> Inferencer<'a> {

        let mut res = None;
        for (a, b, c) in izip!(once(left).chain(comparators), comparators, ops) {
-            let method = comparison_name(*c)
-                .ok_or_else(|| HashSet::from(["unsupported comparator".to_string()]))?
-                .into();
+            if !OpInfo::supports_cmpop(*c) {
+                return Err(HashSet::from(["unsupported comparator".to_string()]));
+            }
+
+            let method = c.op_info().method_name.into();

            let ret = typeof_cmpop(
                self.unifier,
@ -1576,6 +1852,10 @@ impl<'a> Inferencer<'a> {
                a.custom.unwrap(),
                vec![b.custom.unwrap()],
                ret,
+                Some(OperatorInfo::IsComparisonOp {
+                    self_type: left.custom.unwrap(),
+                    operator: *c,
+                }),
            )?);
        }

@ -1676,6 +1956,18 @@ impl<'a> Inferencer<'a> {
        slice: &ast::Expr<Option<Type>>,
        ctx: ExprContext,
    ) -> InferenceResult {
+        let report_unscriptable_error = |unifier: &mut Unifier| {
+            // User is attempting to index into a value of an unsupported type.
+
+            let value_ty = value.custom.unwrap();
+            let value_ty_str = unifier.stringify(value_ty);
+
+            return report_error(
+                format!("'{value_ty_str}' object is not subscriptable").as_str(),
+                slice.location, // using the slice's location (rather than value's) because it is more clear
+            );
+        };
+
        let ty = self.unifier.get_dummy_var().ty;
        match &slice.node {
            ExprKind::Slice { lower, upper, step } => {
@ -1683,7 +1975,16 @@ impl<'a> Inferencer<'a> {
                    self.constrain(v.custom.unwrap(), self.primitives.int32, &v.location)?;
                }
                let list_like_ty = match &*self.unifier.get_ty(value.custom.unwrap()) {
-                    TypeEnum::TList { .. } => self.unifier.add_ty(TypeEnum::TList { ty }),
+                    TypeEnum::TObj { obj_id, params, .. } if *obj_id == PrimDef::List.id() => {
+                        let list_tvar = iter_type_vars(params).nth(0).unwrap();
+                        self.unifier
+                            .subst(
+                                self.primitives.list,
+                                &into_var_map([TypeVar { id: list_tvar.id, ty }]),
+                            )
+                            .unwrap()
+                    }
+
                    TypeEnum::TObj { obj_id, .. } if *obj_id == PrimDef::NDArray.id() => {
                        let (_, ndims) =
                            unpack_ndarray_var_tys(self.unifier, value.custom.unwrap());
@ -1691,7 +1992,9 @@ impl<'a> Inferencer<'a> {
                        make_ndarray_ty(self.unifier, self.primitives, Some(ty), Some(ndims))
                    }

-                    _ => unreachable!(),
+                    _ => {
+                        return report_unscriptable_error(self.unifier);
+                    }
                };
                self.constrain(value.custom.unwrap(), list_like_ty, &value.location)?;
                Ok(list_like_ty)
@ -1756,13 +2059,20 @@ impl<'a> Inferencer<'a> {

                // the index is not a constant, so value can only be a list-like structure
                match &*self.unifier.get_ty(value.custom.unwrap()) {
-                    TypeEnum::TList { .. } => {
+                    TypeEnum::TObj { obj_id, params, .. } if *obj_id == PrimDef::List.id() => {
                        self.constrain(
                            slice.custom.unwrap(),
                            self.primitives.int32,
                            &slice.location,
                        )?;
-                        let list = self.unifier.add_ty(TypeEnum::TList { ty });
+                        let list_tvar = iter_type_vars(params).nth(0).unwrap();
+                        let list = self
+                            .unifier
+                            .subst(
+                                self.primitives.list,
+                                &into_var_map([TypeVar { id: list_tvar.id, ty }]),
+                            )
+                            .unwrap();
                        self.constrain(value.custom.unwrap(), list, &value.location)?;
                        Ok(ty)
                    }
@ -1781,7 +2091,7 @@ impl<'a> Inferencer<'a> {
                        self.constrain(slice.custom.unwrap(), valid_index_ty, &slice.location)?;
                        self.infer_subscript_ndarray(value, slice, ty, ndims)
                    }
-                    _ => unreachable!(),
+                    _ => report_unscriptable_error(self.unifier),
                }
            }
        }
--- a/nac3core/src/typecheck/type_inferencer/test.rs
+++ b/nac3core/src/typecheck/type_inferencer/test.rs
@ -139,6 +139,12 @@ impl TestEnvironment {
            fields: HashMap::new(),
            params: VarMap::new(),
        });
+        let list_elem_tvar = unifier.get_fresh_var(Some("list_elem".into()), None);
+        let list = unifier.add_ty(TypeEnum::TObj {
+            obj_id: PrimDef::List.id(),
+            fields: HashMap::new(),
+            params: into_var_map([list_elem_tvar]),
+        });
        let ndarray_dtype_tvar = unifier.get_fresh_var(Some("ndarray_dtype".into()), None);
        let ndarray_ndims_tvar =
            unifier.get_fresh_const_generic_var(uint64, Some("ndarray_ndims".into()), None);
@ -159,6 +165,7 @@ impl TestEnvironment {
            uint32,
            uint64,
            option,
+            list,
            ndarray,
            size_t: 64,
        };
@ -273,15 +280,35 @@ impl TestEnvironment {
            fields: HashMap::new(),
            params: VarMap::new(),
        });
+        let list_elem_tvar = unifier.get_fresh_var(Some("list_elem".into()), None);
+        let list = unifier.add_ty(TypeEnum::TObj {
+            obj_id: PrimDef::List.id(),
+            fields: HashMap::new(),
+            params: into_var_map([list_elem_tvar]),
+        });
        let ndarray = unifier.add_ty(TypeEnum::TObj {
            obj_id: PrimDef::NDArray.id(),
            fields: HashMap::new(),
            params: VarMap::new(),
        });
        identifier_mapping.insert("None".into(), none);
-        for (i, name) in ["int32", "int64", "float", "bool", "none", "range", "str", "Exception"]
-            .iter()
-            .enumerate()
+        for (i, name) in [
+            "int32",
+            "int64",
+            "float",
+            "bool",
+            "none",
+            "range",
+            "str",
+            "Exception",
+            "uint32",
+            "uint64",
+            "Option",
+            "list",
+            "ndarray",
+        ]
+        .iter()
+        .enumerate()
        {
            top_level_defs.push(
                RwLock::new(TopLevelDef::Class {
@ -289,6 +316,7 @@ impl TestEnvironment {
                    object_id: DefinitionId(i),
                    type_vars: Vec::default(),
                    fields: Vec::default(),
+                    attributes: Vec::default(),
                    methods: Vec::default(),
                    ancestors: Vec::default(),
                    resolver: None,
@ -298,7 +326,7 @@ impl TestEnvironment {
                .into(),
            );
        }
-        let defs = 7;
+        let defs = 12;

        let primitives = PrimitiveStore {
            int32,
@ -312,6 +340,7 @@ impl TestEnvironment {
            uint32,
            uint64,
            option,
+            list,
            ndarray,
            size_t: 64,
        };
@ -331,6 +360,7 @@ impl TestEnvironment {
                object_id: DefinitionId(defs + 1),
                type_vars: vec![tvar.ty],
                fields: [("a".into(), tvar.ty, true)].into(),
+                attributes: Vec::default(),
                methods: Vec::default(),
                ancestors: Vec::default(),
                resolver: None,
@ -365,6 +395,7 @@ impl TestEnvironment {
                object_id: DefinitionId(defs + 2),
                type_vars: Vec::default(),
                fields: [("a".into(), int32, true), ("b".into(), fun, true)].into(),
+                attributes: Vec::default(),
                methods: Vec::default(),
                ancestors: Vec::default(),
                resolver: None,
@ -393,6 +424,7 @@ impl TestEnvironment {
                object_id: DefinitionId(defs + 3),
                type_vars: Vec::default(),
                fields: [("a".into(), bool, true), ("b".into(), fun, false)].into(),
+                attributes: Vec::default(),
                methods: Vec::default(),
                ancestors: Vec::default(),
                resolver: None,
@ -420,6 +452,11 @@ impl TestEnvironment {
            "range".into(),
            "str".into(),
            "exception".into(),
+            "uint32".into(),
+            "uint64".into(),
+            "option".into(),
+            "list".into(),
+            "ndarray".into(),
            "Foo".into(),
            "Bar".into(),
            "Bar2".into(),
--- a/nac3core/src/typecheck/typedef/mod.rs
+++ b/nac3core/src/typecheck/typedef/mod.rs
@ -8,12 +8,15 @@ use std::rc::Rc;
 use std::sync::{Arc, Mutex};
 use std::{borrow::Cow, collections::HashSet};

-use nac3parser::ast::{Location, StrRef};
+use nac3parser::ast::{Cmpop, Location, StrRef, Unaryop};

+use super::magic_methods::Binop;
 use super::type_error::{TypeError, TypeErrorKind};
 use super::unification_table::{UnificationKey, UnificationTable};
 use crate::symbol_resolver::SymbolValue;
+use crate::toplevel::helper::PrimDef;
 use crate::toplevel::{DefinitionId, TopLevelContext, TopLevelDef};
+use crate::typecheck::magic_methods::OpInfo;
 use crate::typecheck::type_inferencer::PrimitiveStore;

 #[cfg(test)]
@ -73,6 +76,28 @@ pub fn iter_type_vars(var_map: &VarMap) -> impl Iterator<Item = TypeVar> + '_ {
    var_map.iter().map(|(&id, &ty)| TypeVar { id, ty })
 }

+#[derive(Debug, Clone)]
+pub enum OperatorInfo {
+    /// The call was written as an unary operation, e.g., `~a` or `not a`.
+    IsUnaryOp {
+        /// The [`Type`] of the `self` object
+        self_type: Type,
+        operator: Unaryop,
+    },
+    /// The call was written as a binary operation, e.g., `a + b` or `a += b`.
+    IsBinaryOp {
+        /// The [`Type`] of the `self` object
+        self_type: Type,
+        operator: Binop,
+    },
+    /// The call was written as a binary comparison operation, e.g., `a < b`.
+    IsComparisonOp {
+        /// The [`Type`] of the `self` object
+        self_type: Type,
+        operator: Cmpop,
+    },
+}
+
 #[derive(Clone)]
 pub struct Call {
    pub posargs: Vec<Type>,
@ -80,6 +105,9 @@ pub struct Call {
    pub ret: Type,
    pub fun: RefCell<Option<Type>>,
    pub loc: Option<Location>,
+
+    /// Details about the associated Python user operator expression of this call, if any.
+    pub operator_info: Option<OperatorInfo>,
 }

 #[derive(Debug, Clone)]
@ -89,6 +117,13 @@ pub struct FuncArg {
    pub default_value: Option<SymbolValue>,
 }

+impl FuncArg {
+    #[must_use]
+    pub fn is_required(&self) -> bool {
+        self.default_value.is_none()
+    }
+}
+
 #[derive(Debug, Clone)]
 pub struct FunSignature {
    pub args: Vec<FuncArg>,
@ -200,12 +235,6 @@ pub enum TypeEnum {
        ty: Vec<Type>,
    },

-    /// A list type.
-    TList {
-        /// The type of elements present in this list.
-        ty: Type,
-    },
-
    /// An object type.
    TObj {
        /// The [`DefinitionId`] of this object type.
@ -239,7 +268,6 @@ impl TypeEnum {
            TypeEnum::TVar { .. } => "TVar",
            TypeEnum::TLiteral { .. } => "TConstant",
            TypeEnum::TTuple { .. } => "TTuple",
-            TypeEnum::TList { .. } => "TList",
            TypeEnum::TObj { .. } => "TObj",
            TypeEnum::TVirtual { .. } => "TVirtual",
            TypeEnum::TCall { .. } => "TCall",
@ -475,9 +503,27 @@ impl Unifier {
                    )
                }
            }
-            TypeEnum::TList { ty } => self
-                .get_instantiations(*ty)
-                .map(|ty| ty.iter().map(|&ty| self.add_ty(TypeEnum::TList { ty })).collect_vec()),
+            TypeEnum::TObj { obj_id, params, .. } if *obj_id == PrimDef::List.id() => {
+                let tv = iter_type_vars(params).nth(0).unwrap();
+
+                let tv_id = if let TypeEnum::TVar { id, .. } =
+                    self.unification_table.probe_value(tv.ty).as_ref()
+                {
+                    *id
+                } else {
+                    tv.id
+                };
+
+                self.get_instantiations(tv.ty).map(|ty_insts| {
+                    ty_insts
+                        .iter()
+                        .map(|&ty_inst| {
+                            self.subst(ty, &into_var_map([TypeVar { id: tv_id, ty: ty_inst }]))
+                                .unwrap_or(ty)
+                        })
+                        .collect()
+                })
+            }
            TypeEnum::TVirtual { ty } => self.get_instantiations(*ty).map(|ty| {
                ty.iter().map(|&ty| self.add_ty(TypeEnum::TVirtual { ty })).collect_vec()
            }),
@ -534,9 +580,7 @@ impl Unifier {

            TVar { .. } => allowed_typevars.iter().any(|b| self.unification_table.unioned(a, *b)),
            TCall { .. } => false,
-            TList { ty }
-            | TVirtual { ty } => self.is_concrete(*ty, allowed_typevars),
-
+            TVirtual { ty } => self.is_concrete(*ty, allowed_typevars),
            TTuple { ty } => ty.iter().all(|ty| self.is_concrete(*ty, allowed_typevars)),
            TObj { params: vars, .. } => {
                vars.values().all(|ty| self.is_concrete(*ty, allowed_typevars))
@ -562,69 +606,229 @@ impl Unifier {
        call: &Call,
        b: Type,
        signature: &FunSignature,
-        required: &[StrRef],
    ) -> Result<(), TypeError> {
+        /*
+            NOTE: scenarios to consider:
+
+            ```python
+            def func1(x: int32, y: int32, z: int32 = 5): pass
+
+            # Normal scenarios
+            func1(23, 45) # OK, z has default
+            func1(23, 45, 67) # OK, z's default is overwritten
+            func1(x = 23, y = 45) # OK, user is using kwargs to set positional args
+            func1(y = 45, x = 23) # OK, kwargs order doesn't matter
+
+            # Error scenarios
+            func1() # ERROR: Missing arguments: x, y
+            func1(23) # ERROR: Missing arguments: y
+            func1(z = 23) # ERROR: Missing arguments: x, y
+            func1(x = 23) # ERROR: Missing arguments: y
+            func1(23, 45, x = 5) # ERROR: Got multiple values for x
+            func1(23, 45, x = 5, y = 6) # ERROR: Got multiple values for x (y too but Python does not report it)
+            func1(23, 45, 67, z = 89) # ERROR: Got multiple values for z
+            func1(23, 45, 67, 89) # ERROR: Function only takes from 2 to 3 positional arguments but 4 were given.
+            func1(23, 45, 67, w = 3) # ERROR: Got an unexpected keyword argument 'w'
+
+            # Error scenarios that do not need to be handled here.
+            func1(23, 45, z = 67, z = 89) # ERROR: Keyword argument repeated: z, the parser panics on this.
+            ```
+        */
+
+        struct ParamInfo<'a> {
+            /// Has this parameter been supplied with an argument already?
+            has_been_supplied: bool,
+            /// The corresponding [`FuncArg`] instance of this parameter (for fast table lookups)
+            param: &'a FuncArg,
+        }
+
        let snapshot = self.unification_table.get_snapshot();
        if self.snapshot.is_none() {
            self.snapshot = Some(snapshot);
        }

-        let Call { posargs, kwargs, ret, fun, loc } = call;
-        let instantiated = self.instantiate_fun(b, signature);
-        let r = self.get_ty(instantiated);
-        let r = r.as_ref();
-        let TypeEnum::TFunc(signature) = r else { unreachable!() };
-        // we check to make sure that all required arguments (those without default
-        // arguments) are provided, and do not provide the same argument twice.
-        let mut required = required.to_vec();
-        let mut all_names: Vec<_> = signature.args.iter().map(|v| (v.name, v.ty)).rev().collect();
-        for (i, t) in posargs.iter().enumerate() {
-            if signature.args.len() <= i {
-                self.restore_snapshot();
-                return Err(TypeError::new(
-                    TypeErrorKind::TooManyArguments {
-                        expected: signature.args.len(),
-                        got: posargs.len() + kwargs.len(),
-                    },
-                    *loc,
-                ));
+        // Get details about the function signature/parameters.
+        let num_params = signature.args.len();
+
+        // Force the type vars in `b` and `signature' to be up-to-date.
+        let b = self.instantiate_fun(b, signature);
+        let TypeEnum::TFunc(signature) = &*self.get_ty(b) else { unreachable!() };
+
+        // Get details about the input arguments
+        let Call { posargs, kwargs, ret, fun, loc, operator_info } = call;
+        let num_args = posargs.len() + kwargs.len();
+
+        // Now we check the arguments against the parameters,
+        // and depending on what `call_info` is, we might change how the behavior `unify_call()`
+        // in hopes to improve user error messages when type checking fails.
+        match operator_info {
+            Some(OperatorInfo::IsBinaryOp { self_type, operator }) => {
+                // The call is written in the form of (say) `a + b`.
+                // Technically, it is `a.__add__(b)`, and they have the following constraints:
+                assert_eq!(posargs.len(), 1);
+                assert_eq!(kwargs.len(), 0);
+                assert_eq!(num_params, 1);
+
+                let other_type = posargs[0]; // the second operand
+                let expected_other_type = signature.args[0].ty;
+
+                let ok = self.unify_impl(expected_other_type, other_type, false).is_ok();
+                if !ok {
+                    self.restore_snapshot();
+                    return Err(TypeError::new(
+                        TypeErrorKind::UnsupportedBinaryOpTypes {
+                            operator: *operator,
+                            lhs_type: *self_type,
+                            rhs_type: other_type,
+                            expected_rhs_type: expected_other_type,
+                        },
+                        *loc,
+                    ));
+                }
            }
-            required.pop();
-            let (name, expected) = all_names.pop().unwrap();
-            self.unify_impl(expected, *t, false).map_err(|_| {
-                self.restore_snapshot();
-                TypeError::new(TypeErrorKind::IncorrectArgType { name, expected, got: *t }, *loc)
-            })?;
-        }
-        for (k, t) in kwargs {
-            if let Some(i) = required.iter().position(|v| v == k) {
-                required.remove(i);
+            Some(OperatorInfo::IsComparisonOp { self_type, operator })
+                if OpInfo::supports_cmpop(*operator) // Otherwise that comparison operator is not supported.
+                =>
+            {
+                // The call is written in the form of (say) `a <= b`.
+                // Technically, it is `a.__le__(b)`, and they have the following constraints:
+                assert_eq!(posargs.len(), 1);
+                assert_eq!(kwargs.len(), 0);
+                assert_eq!(num_params, 1);
+
+                let other_type = posargs[0]; // the second operand
+                let expected_other_type = signature.args[0].ty;
+
+                let ok = self.unify_impl(expected_other_type, other_type, false).is_ok();
+                if !ok {
+                    self.restore_snapshot();
+                    return Err(TypeError::new(
+                        TypeErrorKind::UnsupportedComparsionOpTypes {
+                            operator: *operator,
+                            lhs_type: *self_type,
+                            rhs_type: other_type,
+                            expected_rhs_type: expected_other_type,
+                        },
+                        *loc,
+                    ));
+                }
            }
-            let i = all_names.iter().position(|v| &v.0 == k).ok_or_else(|| {
-                self.restore_snapshot();
-                TypeError::new(TypeErrorKind::UnknownArgName(*k), *loc)
-            })?;
-            let (name, expected) = all_names.remove(i);
-            self.unify_impl(expected, *t, false).map_err(|_| {
-                self.restore_snapshot();
-                TypeError::new(TypeErrorKind::IncorrectArgType { name, expected, got: *t }, *loc)
-            })?;
-        }
-        if !required.is_empty() {
-            self.restore_snapshot();
-            return Err(TypeError::new(
-                TypeErrorKind::MissingArgs(required.iter().join(", ")),
-                *loc,
-            ));
-        }
-        self.unify_impl(*ret, signature.ret, false).map_err(|mut err| {
-            self.restore_snapshot();
-            if err.loc.is_none() {
-                err.loc = *loc;
+            _ => {
+                // Handle [`CallInfo::IsNormalFunctionCall`] and other uninteresting variants
+                // of [`CallInfo`] (e.g, `CallInfo::IsUnaryOp` and unsupported comparison operators)
+
+                // Helper lambdas
+                let mut type_check_arg = |param_name, expected_arg_ty, arg_ty| {
+                    let ok = self.unify_impl(expected_arg_ty, arg_ty, false).is_ok();
+                    if ok {
+                        Ok(())
+                    } else {
+                        // Typecheck failed, throw an error.
+                        self.restore_snapshot();
+                        Err(TypeError::new(
+                            TypeErrorKind::IncorrectArgType {
+                                name: param_name,
+                                expected: expected_arg_ty,
+                                got: arg_ty,
+                            },
+                            *loc,
+                        ))
+                    }
+                };
+
+                // Check for "too many arguments"
+                if num_params < posargs.len() {
+                    let expected_min_count =
+                        signature.args.iter().filter(|param| param.is_required()).count();
+                    let expected_max_count = num_params;
+
+                    self.restore_snapshot();
+                    return Err(TypeError::new(
+                        TypeErrorKind::TooManyArguments {
+                            expected_min_count,
+                            expected_max_count,
+                            got_count: num_args,
+                        },
+                        *loc,
+                    ));
+                }
+
+                // NOTE: order of `param_info_by_name` is leveraged, so use an IndexMap
+                let mut param_info_by_name: IndexMap<StrRef, ParamInfo> = signature
+                    .args
+                    .iter()
+                    .map(|arg| (arg.name, ParamInfo { has_been_supplied: false, param: arg }))
+                    .collect();
+
+                // Now consume all positional arguments and typecheck them.
+                for (&arg_ty, param) in zip(posargs, signature.args.iter()) {
+                    // We will also use this opportunity to mark the corresponding `param_info` as having been supplied.
+                    let param_info = param_info_by_name.get_mut(&param.name).unwrap();
+                    param_info.has_been_supplied = true;
+
+                    // Typecheck
+                    type_check_arg(param.name, param.ty, arg_ty)?;
+                }
+
+                // Now consume all keyword arguments and typecheck them.
+                for (&param_name, &arg_ty) in kwargs {
+                    // We will also use this opportunity to check if this keyword argument is "legal".
+
+                    let Some(param_info) = param_info_by_name.get_mut(&param_name) else {
+                        self.restore_snapshot();
+                        return Err(TypeError::new(
+                            TypeErrorKind::UnknownArgName(param_name),
+                            *loc,
+                        ));
+                    };
+
+                    if param_info.has_been_supplied {
+                        // NOTE: Duplicate keyword argument (i.e., `hello(1, 2, 3, arg = 4, arg = 5)`)
+                        // is IMPOSSIBLE as the parser would have already failed.
+                        // We only have to care about "got multiple values for XYZ"
+
+                        self.restore_snapshot();
+                        return Err(TypeError::new(
+                            TypeErrorKind::GotMultipleValues { name: param_name },
+                            *loc,
+                        ));
+                    }
+
+                    param_info.has_been_supplied = true;
+
+                    // Typecheck
+                    type_check_arg(param_name, param_info.param.ty, arg_ty)?;
+                }
+
+                // After checking posargs and kwargs, check if there are any
+                // unsupplied required parameters, and throw an error if they exist.
+                let missing_arg_names = param_info_by_name
+                    .values()
+                    .filter(|param_info| {
+                        param_info.param.is_required() && !param_info.has_been_supplied
+                    })
+                    .map(|param_info| param_info.param.name)
+                    .collect_vec();
+                if !missing_arg_names.is_empty() {
+                    self.restore_snapshot();
+                    return Err(TypeError::new(
+                        TypeErrorKind::MissingArgs { missing_arg_names },
+                        *loc,
+                    ));
+                }
+
+                // Finally, check the Call's return type
+                self.unify_impl(*ret, signature.ret, false).map_err(|mut err| {
+                    self.restore_snapshot();
+                    if err.loc.is_none() {
+                        err.loc = *loc;
+                    }
+                    err
+                })?;
            }
-            err
-        })?;
-        *fun.borrow_mut() = Some(instantiated);
+        }
+
+        *fun.borrow_mut() = Some(b);

        self.discard_snapshot(snapshot);
        Ok(())
@ -785,22 +989,6 @@ impl Unifier {
                self.unify_impl(x, b, false)?;
                self.set_a_to_b(a, x);
            }
-            (TVar { fields: Some(fields), range, is_const_generic: false, .. }, TList { ty }) => {
-                for (k, v) in fields {
-                    match *k {
-                        RecordKey::Int(_) => {
-                            self.unify_impl(v.ty, *ty, false).map_err(|e| e.at(v.loc))?;
-                        }
-                        RecordKey::Str(_) => {
-                            return Err(TypeError::new(TypeErrorKind::NoSuchField(*k, b), v.loc))
-                        }
-                    }
-                }
-                let x = self.check_var_compatibility(b, range)?.unwrap_or(b);
-                self.unify_impl(x, b, false)?;
-                self.set_a_to_b(a, x);
-            }
-
            (
                TVar { id: id1, range: ty1, is_const_generic: true, .. },
                TVar { id: id2, range: ty2, .. },
@ -879,13 +1067,7 @@ impl Unifier {
                }
                self.set_a_to_b(a, b);
            }
-            (TList { ty: ty1 }, TList { ty: ty2 }) => {
-                if self.unify_impl(*ty1, *ty2, false).is_err() {
-                    return Err(TypeError::new(TypeErrorKind::IncompatibleTypes(a, b), None));
-                }
-                self.set_a_to_b(a, b);
-            }
-            (TVar { fields: Some(map), range, .. }, TObj { fields, .. }) => {
+            (TVar { fields: Some(map), range, .. }, TObj { obj_id, fields, params }) => {
                for (k, field) in map {
                    match *k {
                        RecordKey::Str(s) => {
@ -904,10 +1086,18 @@ impl Unifier {
                            self.unify_impl(field.ty, ty, false).map_err(|v| v.at(field.loc))?;
                        }
                        RecordKey::Int(_) => {
-                            return Err(TypeError::new(
-                                TypeErrorKind::NoSuchField(*k, b),
-                                field.loc,
-                            ))
+                            // Allow expressions such as list[0]
+                            if *obj_id == PrimDef::List.id() {
+                                let ty = iter_type_vars(params).nth(0).unwrap().ty;
+
+                                self.unify_impl(field.ty, ty, false)
+                                    .map_err(|e| e.at(field.loc))?;
+                            } else {
+                                return Err(TypeError::new(
+                                    TypeErrorKind::NoSuchField(*k, b),
+                                    field.loc,
+                                ));
+                            }
                        }
                    }
                }
@ -990,17 +1180,10 @@ impl Unifier {
                self.unification_table.set_value(b, Rc::new(TCall(calls)));
            }
            (TCall(calls), TFunc(signature)) => {
-                let required: Vec<StrRef> = signature
-                    .args
-                    .iter()
-                    .filter(|v| v.default_value.is_none())
-                    .map(|v| v.name)
-                    .rev()
-                    .collect();
                // we unify every calls to the function signature.
                for c in calls {
                    let call = self.calls[c.0].clone();
-                    self.unify_call(&call, b, signature, &required)?;
+                    self.unify_call(&call, b, signature)?;
                }
                self.set_a_to_b(a, b);
            }
@ -1129,9 +1312,6 @@ impl Unifier {
                    ty.iter().map(|v| self.internal_stringify(*v, obj_to_name, var_to_name, notes));
                format!("tuple[{}]", fields.join(", "))
            }
-            TypeEnum::TList { ty } => {
-                format!("list[{}]", self.internal_stringify(*ty, obj_to_name, var_to_name, notes))
-            }
            TypeEnum::TVirtual { ty } => {
                format!(
                    "virtual[{}]",
@ -1264,9 +1444,6 @@ impl Unifier {
                    None
                }
            }
-            TypeEnum::TList { ty } => {
-                self.subst_impl(*ty, mapping, cache).map(|t| self.add_ty(TypeEnum::TList { ty: t }))
-            }
            TypeEnum::TVirtual { ty } => self
                .subst_impl(*ty, mapping, cache)
                .map(|t| self.add_ty(TypeEnum::TVirtual { ty: t })),
@ -1277,6 +1454,7 @@ impl Unifier {
                // This is also used to prevent infinite substitution...
                let need_subst = params.values().any(|v| {
                    let ty = self.unification_table.probe_value(*v);
+                    // TODO(Derppening): #444
                    if let TypeEnum::TVar { id, .. } = ty.as_ref() {
                        mapping.contains_key(id)
                    } else {
@ -1433,8 +1611,22 @@ impl Unifier {
                    Ok(None)
                }
            }
-            (TList { ty: ty1 }, TList { ty: ty2 }) => {
-                Ok(self.get_intersection(*ty1, *ty2)?.map(|ty| self.add_ty(TList { ty })))
+            // TODO(Derppening): #444
+            (
+                TObj { obj_id: id1, fields, params: params1 },
+                TObj { obj_id: id2, params: params2, .. },
+            ) if *id1 == PrimDef::List.id() && *id2 == PrimDef::List.id() => {
+                let tv_id = iter_type_vars(params1).nth(0).unwrap().id;
+                let ty1 = iter_type_vars(params1).nth(0).unwrap().ty;
+                let ty2 = iter_type_vars(params2).nth(0).unwrap().ty;
+
+                Ok(self.get_intersection(ty1, ty2)?.map(|ty| {
+                    self.add_ty(TObj {
+                        obj_id: *id1,
+                        fields: fields.clone(),
+                        params: into_var_map([TypeVar { id: tv_id, ty }]),
+                    })
+                }))
            }
            (TVirtual { ty: ty1 }, TVirtual { ty: ty2 }) => {
                Ok(self.get_intersection(*ty1, *ty2)?.map(|ty| self.add_ty(TVirtual { ty })))
--- a/nac3core/src/typecheck/typedef/test.rs
+++ b/nac3core/src/typecheck/typedef/test.rs
@ -32,10 +32,7 @@ impl Unifier {
                ty1.len() == ty2.len()
                    && ty1.iter().zip(ty2.iter()).all(|(t1, t2)| self.eq(*t1, *t2))
            }
-            (TypeEnum::TList { ty: ty1 }, TypeEnum::TList { ty: ty2 })
-            | (TypeEnum::TVirtual { ty: ty1 }, TypeEnum::TVirtual { ty: ty2 }) => {
-                self.eq(*ty1, *ty2)
-            }
+            (TypeEnum::TVirtual { ty: ty1 }, TypeEnum::TVirtual { ty: ty2 }) => self.eq(*ty1, *ty2),
            (
                TypeEnum::TObj { obj_id: id1, params: params1, .. },
                TypeEnum::TObj { obj_id: id2, params: params2, .. },
@ -119,6 +116,15 @@ impl TestEnvironment {
                params: into_var_map([tvar]),
            }),
        );
+        let tvar = unifier.get_dummy_var();
+        type_mapping.insert(
+            "list".into(),
+            unifier.add_ty(TypeEnum::TObj {
+                obj_id: PrimDef::List.id(),
+                fields: HashMap::new(),
+                params: into_var_map([tvar]),
+            }),
+        );

        TestEnvironment { unifier, type_mapping }
    }
@ -133,6 +139,36 @@ impl TestEnvironment {
        // for testing only, so we can just panic when the input is malformed
        let end = typ.find(|c| ['[', ',', ']', '='].contains(&c)).unwrap_or(typ.len());
        match &typ[..end] {
+            "list" => {
+                let mut s = &typ[end..];
+                assert_eq!(&s[0..1], "[");
+                let mut ty = Vec::new();
+                while &s[0..1] != "]" {
+                    let result = self.internal_parse(&s[1..], mapping);
+                    ty.push(result.0);
+                    s = result.1;
+                }
+
+                assert_eq!(ty.len(), 1);
+
+                let list_elem_tvar = if let TypeEnum::TObj { params, .. } =
+                    &*self.unifier.get_ty_immutable(self.type_mapping["list"])
+                {
+                    iter_type_vars(params).next().unwrap()
+                } else {
+                    unreachable!()
+                };
+
+                (
+                    self.unifier
+                        .subst(
+                            self.type_mapping["list"],
+                            &into_var_map([TypeVar { id: list_elem_tvar.id, ty: ty[0] }]),
+                        )
+                        .unwrap(),
+                    &s[1..],
+                )
+            }
            "tuple" => {
                let mut s = &typ[end..];
                assert_eq!(&s[0..1], "[");
@ -144,12 +180,6 @@ impl TestEnvironment {
                }
                (self.unifier.add_ty(TypeEnum::TTuple { ty }), &s[1..])
            }
-            "list" => {
-                assert_eq!(&typ[end..=end], "[");
-                let (ty, s) = self.internal_parse(&typ[end + 1..], mapping);
-                assert_eq!(&s[0..1], "]");
-                (self.unifier.add_ty(TypeEnum::TList { ty }), &s[1..])
-            }
            "Record" => {
                let mut s = &typ[end..];
                assert_eq!(&s[0..1], "[");
@ -274,7 +304,7 @@ fn test_unify(
        ("v1", "tuple[int]"),
        ("v2", "list[int]"),
    ],
-    (("v1", "v2"), "Incompatible types: list[0] and tuple[0]")
+    (("v1", "v2"), "Incompatible types: 11[0] and tuple[0]")
    ; "type mismatch"
 )]
 #[test_case(2,
@ -298,7 +328,7 @@ fn test_unify(
        ("v1", "Record[a=float,b=int]"),
        ("v2", "Foo[v3]"),
    ],
-    (("v1", "v2"), "`3[typevar4]::b` field/method does not exist")
+    (("v1", "v2"), "`3[typevar5]::b` field/method does not exist")
    ; "record obj merge"
 )]
 /// Test cases for invalid unifications.
@ -388,6 +418,14 @@ fn test_typevar_range() {
    let int_list = env.parse("list[int]", &HashMap::new());
    let float_list = env.parse("list[float]", &HashMap::new());

+    let list_elem_tvar = if let TypeEnum::TObj { params, .. } =
+        &*env.unifier.get_ty_immutable(env.type_mapping["list"])
+    {
+        iter_type_vars(params).next().unwrap()
+    } else {
+        unreachable!()
+    };
+
    // unification between v and int
    // where v in (int, bool)
    let v = env.unifier.get_fresh_var_with_range(&[int, boolean], None, None).ty;
@ -398,7 +436,7 @@ fn test_typevar_range() {
    let v = env.unifier.get_fresh_var_with_range(&[int, boolean], None, None).ty;
    assert_eq!(
        env.unify(int_list, v),
-        Err("Expected any one of these types: 0, 2, but got list[0]".to_string())
+        Err("Expected any one of these types: 0, 2, but got 11[0]".to_string())
    );

    // unification between v and float
@ -410,7 +448,11 @@ fn test_typevar_range() {
    );

    let v1 = env.unifier.get_fresh_var_with_range(&[int, boolean], None, None).ty;
-    let v1_list = env.unifier.add_ty(TypeEnum::TList { ty: v1 });
+    let v1_list = env.unifier.add_ty(TypeEnum::TObj {
+        obj_id: env.type_mapping["list"].obj_id(&env.unifier).unwrap(),
+        fields: Mapping::default(),
+        params: into_var_map([TypeVar { id: list_elem_tvar.id, ty: v1 }]),
+    });
    let v = env.unifier.get_fresh_var_with_range(&[int, v1_list], None, None).ty;
    // unification between v and int
    // where v in (int, list[v1]), v1 in (int, bool)
@ -424,9 +466,10 @@ fn test_typevar_range() {
    let v = env.unifier.get_fresh_var_with_range(&[int, v1_list], None, None).ty;
    // unification between v and list[float]
    // where v in (int, list[v1]), v1 in (int, bool)
+    println!("float_list: {}, v: {}", env.unifier.stringify(float_list), env.unifier.stringify(v));
    assert_eq!(
        env.unify(float_list, v),
-        Err("Expected any one of these types: 0, list[typevar5], but got list[1]\n\nNotes:\n    typevar5 ∈ {0, 2}".to_string())
+        Err("Expected any one of these types: 0, 11[typevar6], but got 11[1]\n\nNotes:\n    typevar6 ∈ {0, 2}".to_string())
    );

    let a = env.unifier.get_fresh_var_with_range(&[int, float], None, None).ty;
@ -441,34 +484,66 @@ fn test_typevar_range() {

    let a = env.unifier.get_fresh_var_with_range(&[int, float], None, None).ty;
    let b = env.unifier.get_fresh_var_with_range(&[boolean, float], None, None).ty;
-    let a_list = env.unifier.add_ty(TypeEnum::TList { ty: a });
+    let a_list = env.unifier.add_ty(TypeEnum::TObj {
+        obj_id: env.type_mapping["list"].obj_id(&env.unifier).unwrap(),
+        fields: Mapping::default(),
+        params: into_var_map([TypeVar { id: list_elem_tvar.id, ty: a }]),
+    });
    let a_list = env.unifier.get_fresh_var_with_range(&[a_list], None, None).ty;
-    let b_list = env.unifier.add_ty(TypeEnum::TList { ty: b });
+    let b_list = env.unifier.add_ty(TypeEnum::TObj {
+        obj_id: env.type_mapping["list"].obj_id(&env.unifier).unwrap(),
+        fields: Mapping::default(),
+        params: into_var_map([TypeVar { id: list_elem_tvar.id, ty: b }]),
+    });
    let b_list = env.unifier.get_fresh_var_with_range(&[b_list], None, None).ty;
    env.unifier.unify(a_list, b_list).unwrap();
-    let float_list = env.unifier.add_ty(TypeEnum::TList { ty: float });
+    let float_list = env.unifier.add_ty(TypeEnum::TObj {
+        obj_id: env.type_mapping["list"].obj_id(&env.unifier).unwrap(),
+        fields: Mapping::default(),
+        params: into_var_map([TypeVar { id: list_elem_tvar.id, ty: float }]),
+    });
    env.unifier.unify(a_list, float_list).unwrap();
    // previous unifications should not affect a and b
    env.unifier.unify(a, int).unwrap();

    let a = env.unifier.get_fresh_var_with_range(&[int, float], None, None).ty;
    let b = env.unifier.get_fresh_var_with_range(&[boolean, float], None, None).ty;
-    let a_list = env.unifier.add_ty(TypeEnum::TList { ty: a });
-    let b_list = env.unifier.add_ty(TypeEnum::TList { ty: b });
+    let a_list = env.unifier.add_ty(TypeEnum::TObj {
+        obj_id: env.type_mapping["list"].obj_id(&env.unifier).unwrap(),
+        fields: Mapping::default(),
+        params: into_var_map([TypeVar { id: list_elem_tvar.id, ty: a }]),
+    });
+    let b_list = env.unifier.add_ty(TypeEnum::TObj {
+        obj_id: env.type_mapping["list"].obj_id(&env.unifier).unwrap(),
+        fields: Mapping::default(),
+        params: into_var_map([TypeVar { id: list_elem_tvar.id, ty: b }]),
+    });
    env.unifier.unify(a_list, b_list).unwrap();
-    let int_list = env.unifier.add_ty(TypeEnum::TList { ty: int });
+    let int_list = env.unifier.add_ty(TypeEnum::TObj {
+        obj_id: env.type_mapping["list"].obj_id(&env.unifier).unwrap(),
+        fields: Mapping::default(),
+        params: into_var_map([TypeVar { id: list_elem_tvar.id, ty: int }]),
+    });
    assert_eq!(
        env.unify(a_list, int_list),
-        Err("Incompatible types: list[typevar22] and list[0]\
-            \n\nNotes:\n    typevar22 ∈ {1}"
+        Err("Incompatible types: 11[typevar23] and 11[0]\
+            \n\nNotes:\n    typevar23 ∈ {1}"
            .into())
    );

    let a = env.unifier.get_fresh_var_with_range(&[int, float], None, None).ty;
    let b = env.unifier.get_dummy_var().ty;
-    let a_list = env.unifier.add_ty(TypeEnum::TList { ty: a });
+    let a_list = env.unifier.add_ty(TypeEnum::TObj {
+        obj_id: env.type_mapping["list"].obj_id(&env.unifier).unwrap(),
+        fields: Mapping::default(),
+        params: into_var_map([TypeVar { id: list_elem_tvar.id, ty: a }]),
+    });
    let a_list = env.unifier.get_fresh_var_with_range(&[a_list], None, None).ty;
-    let b_list = env.unifier.add_ty(TypeEnum::TList { ty: b });
+    let b_list = env.unifier.add_ty(TypeEnum::TObj {
+        obj_id: env.type_mapping["list"].obj_id(&env.unifier).unwrap(),
+        fields: Mapping::default(),
+        params: into_var_map([TypeVar { id: list_elem_tvar.id, ty: b }]),
+    });
    env.unifier.unify(a_list, b_list).unwrap();
    assert_eq!(
        env.unify(b, boolean),
@ -482,16 +557,25 @@ fn test_rigid_var() {
    let a = env.unifier.get_fresh_rigid_var(None, None).ty;
    let b = env.unifier.get_fresh_rigid_var(None, None).ty;
    let x = env.unifier.get_dummy_var().ty;
-    let list_a = env.unifier.add_ty(TypeEnum::TList { ty: a });
-    let list_x = env.unifier.add_ty(TypeEnum::TList { ty: x });
+    let list_elem_tvar = env.unifier.get_fresh_var(Some("list_elem".into()), None);
+    let list_a = env.unifier.add_ty(TypeEnum::TObj {
+        obj_id: env.type_mapping["list"].obj_id(&env.unifier).unwrap(),
+        fields: Mapping::default(),
+        params: into_var_map([TypeVar { id: list_elem_tvar.id, ty: a }]),
+    });
+    let list_x = env.unifier.add_ty(TypeEnum::TObj {
+        obj_id: env.type_mapping["list"].obj_id(&env.unifier).unwrap(),
+        fields: Mapping::default(),
+        params: into_var_map([TypeVar { id: list_elem_tvar.id, ty: x }]),
+    });
    let int = env.parse("int", &HashMap::new());
    let list_int = env.parse("list[int]", &HashMap::new());

-    assert_eq!(env.unify(a, b), Err("Incompatible types: typevar3 and typevar2".to_string()));
+    assert_eq!(env.unify(a, b), Err("Incompatible types: typevar4 and typevar3".to_string()));
    env.unifier.unify(list_a, list_x).unwrap();
    assert_eq!(
        env.unify(list_x, list_int),
-        Err("Incompatible types: list[typevar2] and list[0]".to_string())
+        Err("Incompatible types: 11[typevar3] and 11[0]".to_string())
    );

    env.unifier.replace_rigid_var(a, int);
@ -506,10 +590,21 @@ fn test_instantiation() {
    let float = env.parse("float", &HashMap::new());
    let list_int = env.parse("list[int]", &HashMap::new());

-    let obj_map: HashMap<_, _> = [(0usize, "int"), (1, "float"), (2, "bool")].into();
+    let list_elem_tvar = if let TypeEnum::TObj { params, .. } =
+        &*env.unifier.get_ty_immutable(env.type_mapping["list"])
+    {
+        iter_type_vars(params).next().unwrap()
+    } else {
+        unreachable!()
+    };
+
+    let obj_map: HashMap<_, _> = [(0usize, "int"), (1, "float"), (2, "bool"), (11, "list")].into();

    let v = env.unifier.get_fresh_var_with_range(&[int, boolean], None, None).ty;
-    let list_v = env.unifier.add_ty(TypeEnum::TList { ty: v });
+    let list_v = env
+        .unifier
+        .subst(env.type_mapping["list"], &into_var_map([TypeVar { id: list_elem_tvar.id, ty: v }]))
+        .unwrap();
    let v1 = env.unifier.get_fresh_var_with_range(&[list_v, int], None, None).ty;
    let v2 = env.unifier.get_fresh_var_with_range(&[list_int, float], None, None).ty;
    let t = env.unifier.get_dummy_var().ty;
@ -536,7 +631,7 @@ fn test_instantiation() {
        tuple[int, list[bool], list[int]]
        tuple[int, list[int], float]
        tuple[int, list[int], list[int]]
-        v5"
+        v6"
    }
    .split('\n')
    .collect_vec();
--- a/nac3standalone/demo/demo.c
+++ b/nac3standalone/demo/demo.c
@ -44,6 +44,15 @@ void output_float64(double x) {
    }
 }

+void output_range(int32_t range[3]) {
+    printf("range(");
+    printf("%d, %d", range[0], range[1]);
+    if (range[2] != 1) {
+        printf(", %d", range[2]);
+    }
+    puts(")");
+}
+
 void output_asciiart(int32_t x) {
    static const char *chars = " .,-:;i+hHM$*#@    ";
    if (x < 0) {
@ -79,6 +88,10 @@ void output_str(struct cslice *slice) {
    for (usize i = 0; i < slice->len; ++i) {
        putchar(data[i]);
    }
+}
+
+void output_strln(struct cslice *slice) {
+    output_str(slice);
    putchar('\n');
 }

--- a/nac3standalone/demo/interpret_demo.py
+++ b/nac3standalone/demo/interpret_demo.py
@ -107,6 +107,9 @@ def patch(module):
    def output_float(x):
        print("%f" % x)

+    def output_strln(x):
+        print(x, end='')
+
    def dbg_stack_address(_):
        return 0

@ -120,6 +123,8 @@ def patch(module):
            return output_asciiart
        elif name == "output_float64":
            return output_float
+        elif name == "output_str":
+            return output_strln
        elif name in {
            "output_bool",
            "output_int32",
@ -127,7 +132,8 @@ def patch(module):
            "output_int32_list",
            "output_uint32",
            "output_uint64",
-            "output_str",
+            "output_strln",
+            "output_range",
        }:
            return print
        elif name == "dbg_stack_address":
@ -226,8 +232,6 @@ def patch(module):
    module.np_full = np.full
    module.np_eye = np.eye
    module.np_identity = np.identity
-    module.np_any = np.any
-    module.np_all = np.all

 def file_import(filename, prefix="file_import_"):
    filename = pathlib.Path(filename)
--- a/nac3standalone/demo/src/classes.py
+++ b/nac3standalone/demo/src/classes.py
@ -7,7 +7,7 @@ def output_int64(x: int64):
    ...

@extern
-def output_str(x: str):
+def output_strln(x: str):
    ...


@ -33,7 +33,7 @@ class A:

 class Initless:
    def foo(self):
-        output_str("hello")
+        output_strln("hello")

 def run() -> int32:
    a = A(10)
--- a/nac3standalone/demo/src/demo_test.py
+++ b/nac3standalone/demo/src/demo_test.py
@ -22,6 +22,10 @@ def output_uint64(x: uint64):
 def output_float64(x: float):
    ...

+@extern
+def output_range(x: range):
+    ...
+
@extern
 def output_int32_list(x: list[int32]):
    ...
@ -34,6 +38,10 @@ def output_asciiart(x: int32):
 def output_str(x: str):
    ...

+@extern
+def output_strln(x: str):
+    ...
+
 def test_output_bool():
    output_bool(True)
    output_bool(False)
@ -59,6 +67,15 @@ def test_output_float64():
    output_float64(16.25)
    output_float64(-16.25)

+def test_output_range():
+    r = range(1, 100, 5)
+    output_int32(r.start)
+    output_int32(r.stop)
+    output_int32(r.step)
+    output_range(range(10))
+    output_range(range(1, 10))
+    output_range(range(1, 10, 2))
+
 def test_output_asciiart():
    for i in range(17):
        output_asciiart(i)
@ -68,7 +85,8 @@ def test_output_int32_list():
    output_int32_list([0, 1, 3, 5, 10])

 def test_output_str_family():
-    output_str("hello world")
+    output_str("hello")
+    output_strln(" world")

 def run() -> int32:
    test_output_bool()
@ -77,6 +95,7 @@ def run() -> int32:
    test_output_uint32()
    test_output_uint64()
    test_output_float64()
+    test_output_range()
    test_output_asciiart()
    test_output_int32_list()
    test_output_str_family()
--- a/nac3standalone/demo/src/lists.py
+++ b/nac3standalone/demo/src/lists.py
@ -1,3 +1,7 @@
+@extern
+def output_bool(x: bool):
+    ...
+
@extern
 def output_int32_list(x: list[int32]):
    ...
@ -30,6 +34,32 @@ def run() -> int32:

    get_list_slice()
    list_slice_assignment()
+
+    output_int32_list([1, 2, 3] + [4, 5, 6])
+    output_int32_list([1, 2, 3] * 3)
+    output_bool([] == [])
+    output_bool([0] == [])
+    output_bool([0] == [0])
+    output_bool([0, 1] == [0])
+    output_bool([0, 1] == [0, 1])
+    output_bool([] != [])
+    output_bool([0] != [])
+    output_bool([0] != [0])
+    output_bool([0] != [0, 1])
+    output_bool([0, 1] != [0, 1])
+    output_bool([] == [] == [])
+    output_bool([0] == [0] == [0])
+    output_bool([0, 1] == [0] == [0, 1])
+    output_bool([0, 1] == [0, 1] == [0])
+    output_bool([0] == [0, 1] == [0, 1])
+    output_bool([0, 1] == [0, 1] == [0, 1])
+    output_bool([] != [] != [])
+    output_bool([0] != [0] != [0])
+    output_bool([0, 1] != [0] != [0, 1])
+    output_bool([0, 1] != [0, 1] != [0])
+    output_bool([0] != [0, 1] != [0, 1])
+    output_bool([0, 1] != [0, 1] != [0, 1])
+
    return 0

 def get_list_slice():
--- a/nac3standalone/demo/src/loop_try_break.py
+++ b/nac3standalone/demo/src/loop_try_break.py
@ -23,11 +23,12 @@ def run() -> int32:
                    output_int32(x)
                    output_str(" * ")
                    output_float64(n / x)
+                    output_str("\n")
            except:  # Assume this is intended to catch x == 0
                break
        else:
            # loop fell through without finding a factor
            output_int32(n)
-            output_str(" is a prime number")
+            output_str(" is a prime number\n")

    return 0
--- a/nac3standalone/demo/src/math.py
+++ b/nac3standalone/demo/src/math.py
@ -37,7 +37,7 @@ def test_round64():
        output_int64(round64(x))

 def test_np_round():
-    for x in [-1.5, -0.5, 0.5, 1.5, dbl_inf(), -dbl_inf(), dbl_nan()]:
+    for x in [-1.5, -0.5, 0.5, 1.5, dbl_inf(), -dbl_inf(), dbl_nan(), 0.0, -0.0, 1.6, 1.4, -1.4, -1.6]:
        output_float64(np_round(x))

 def test_np_isnan():
--- a/nac3standalone/demo/src/ndarray.py
+++ b/nac3standalone/demo/src/ndarray.py
@ -71,17 +71,44 @@ def output_ndarray_float_2(n: ndarray[float, Literal[2]]):
 def consume_ndarray_1(n: ndarray[float, Literal[1]]):
    pass

+def consume_ndarray_2(n: ndarray[float, Literal[2]]):
+    pass
+
 def test_ndarray_ctor():
    n: ndarray[float, Literal[1]] = np_ndarray([1])
    consume_ndarray_1(n)

 def test_ndarray_empty():
-    n: ndarray[float, 1] = np_empty([1])
-    consume_ndarray_1(n)
+    n1: ndarray[float, 1] = np_empty([1])
+    consume_ndarray_1(n1)
+
+    n2: ndarray[float, 1] = np_empty(10)
+    consume_ndarray_1(n2)
+
+    n3: ndarray[float, 1] = np_empty((2,))
+    consume_ndarray_1(n3)
+
+    n4: ndarray[float, 2] = np_empty((4, 4))
+    consume_ndarray_2(n4)
+
+    dim4 = (5, 2)
+    n5: ndarray[float, 2] = np_empty(dim4)
+    consume_ndarray_2(n5)

 def test_ndarray_zeros():
-    n: ndarray[float, 1] = np_zeros([1])
-    output_ndarray_float_1(n)
+    n1: ndarray[float, 1] = np_zeros([1])
+    output_ndarray_float_1(n1)
+
+    k = 3 + int32(n1[0]) # to test variable shape inputs
+    n2: ndarray[float, 1] = np_zeros(k * k)
+    output_ndarray_float_1(n2)
+
+    n3: ndarray[float, 1] = np_zeros((k * 2,))
+    output_ndarray_float_1(n3)
+
+    dim4 = (3, 2 * k)
+    n4: ndarray[float, 2] = np_zeros(dim4)
+    output_ndarray_float_2(n4)

 def test_ndarray_ones():
    n: ndarray[float, 1] = np_ones([1])
@ -1388,48 +1415,6 @@ def test_ndarray_nextafter_broadcast_rhs_scalar():
    output_ndarray_float_2(nextafter_x_zeros)
    output_ndarray_float_2(nextafter_x_ones)

-def test_ndarray_any():
-    x1 = np_identity(5)
-    y1 = np_any(x1)
-    output_ndarray_float_2(x1)
-    output_bool(y1)
-
-    x2 = np_identity(1)
-    y2 = np_any(x2)
-    output_ndarray_float_2(x2)
-    output_bool(y2)
-
-    x3 = np_array([[1.0, 2.0], [3.0, 4.0]])
-    y3 = np_any(x3)
-    output_ndarray_float_2(x3)
-    output_bool(y3)
-
-    x4 = np_zeros([3, 5])
-    y4 = np_any(x4)
-    output_ndarray_float_2(x4)
-    output_bool(y4)
-
-def test_ndarray_all():
-    x1 = np_identity(5)
-    y1 = np_all(x1)
-    output_ndarray_float_2(x1)
-    output_bool(y1)
-
-    x2 = np_identity(1)
-    y2 = np_all(x2)
-    output_ndarray_float_2(x2)
-    output_bool(y2)
-
-    x3 = np_array([[1.0, 2.0], [3.0, 4.0]])
-    y3 = np_all(x3)
-    output_ndarray_float_2(x3)
-    output_bool(y3)
-
-    x4 = np_zeros([3, 5])
-    y4 = np_all(x4)
-    output_ndarray_float_2(x4)
-    output_bool(y4)
-
 def run() -> int32:
    test_ndarray_ctor()
    test_ndarray_empty()
@ -1607,7 +1592,4 @@ def run() -> int32:
    test_ndarray_nextafter_broadcast_lhs_scalar()
    test_ndarray_nextafter_broadcast_rhs_scalar()

-    test_ndarray_any()
-    test_ndarray_all()
-
    return 0
--- a/nac3standalone/src/main.rs
+++ b/nac3standalone/src/main.rs
@ -340,7 +340,19 @@ fn main() {
    let signature = store.from_signature(&mut composer.unifier, &primitive, &signature, &mut cache);
    let signature = store.add_cty(signature);

-    composer.start_analysis(true).unwrap();
+    if let Err(errors) = composer.start_analysis(true) {
+        let error_count = errors.len();
+        eprintln!("{error_count} error(s) occurred during top level analysis.");
+
+        for (error_i, error) in errors.iter().enumerate() {
+            let error_num = error_i + 1;
+            eprintln!("=========== ERROR {error_num}/{error_count} ============");
+            eprintln!("{error}");
+        }
+        eprintln!("==================================");
+
+        panic!("top level analysis failed");
+    }

    let top_level = Arc::new(composer.make_top_level_context());

--- a/nix/windows/default.nix
+++ b/nix/windows/default.nix
@ -81,6 +81,7 @@ 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 {
--- a/nix/windows/msys2_packages.nix
+++ b/nix/windows/msys2_packages.nix
@ -1,15 +1,15 @@
 { pkgs } : [

 (pkgs.fetchurl {
-  url = "https://mirror.msys2.org/mingw/clang64/mingw-w64-clang-x86_64-libunwind-18.1.2-1-any.pkg.tar.zst";
-  sha256 = "0ksz7xz1lbwsmdr9sa1444k0dlfkbd8k11pq7w08ir7r1wjy6fid";
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Author	SHA1	Message	Date
lyken	87d2a4ed59	WIP	2024-07-10 17:27:10 +08:00
lyken	9aae290727	core: irrt general numpy broadcasting	2024-07-10 17:05:01 +08:00
lyken	d18c769cdc	core: irrt general numpy slicing	2024-07-10 14:05:08 +08:00
lyken	f41f06aec7	core: more irrt	2024-07-10 11:56:31 +08:00
lyken	1303265785	core: build.rs rewrite regex to capture `= type`	2024-07-10 10:17:45 +08:00
lyken	e9cf6ce1e5	core: move irrt c++ sources to /nac3core/irrt	2024-07-10 10:17:45 +08:00
lyken	bc91ab9b13	core: IRRT -Werror=return-type	2024-07-10 10:17:43 +08:00
lyken	1e06a3d199	core: add irrt_test	2024-07-10 10:11:07 +08:00
lyken	87511ac749	core: comment out numpy	2024-07-10 10:05:07 +08:00
Sebastien Bourdeauducq	d658d9b00e	update dependencies, Python 3.12 on Linux	2024-07-09 23:56:12 +08:00
abdul124	eeb474f9e6	core: reduce code duplication in codegen/extern_fns (#453 ) Used macros to reduce code duplication in `codegen/extern_fns` Reviewed-on: M-Labs/nac3#453 Co-authored-by: abdul124 <ar@m-labs.hk> Co-committed-by: abdul124 <ar@m-labs.hk>	2024-07-09 16:31:08 +08:00
abdul124	88b72af2d1	core/llvm_intrinsic: improve macro name and comments	2024-07-09 16:30:32 +08:00
abdul124	b73f6c4d68	core: reduce code duplication in codegen/llvm_intrinsic	2024-07-09 16:30:32 +08:00
David Mak	f47cdec650	standalone: Fix output format of output_range	2024-07-09 13:55:48 +08:00
David Mak	d656880e44	standalone: Fix missing implementation for output_range	2024-07-09 13:53:50 +08:00
David Mak	a91602915a	core: Fix missing fields in range type	2024-07-09 13:53:50 +08:00
David Mak	1c56005a01	core: Reformat and modernize irrt.cpp - Use anon namespace instead of static - Use using declaration instead of typedef - Align pointers to the type instead of the identifier	2024-07-09 13:53:50 +08:00
David Mak	bc40a32524	core: Add report_type_error to enable more code reuse	2024-07-09 13:44:47 +08:00
David Mak	c820daf5f8	core: Apply cargo format	2024-07-09 13:32:10 +08:00
David Mak	25d2de67f7	standalone: Add output_range and tests	2024-07-09 04:44:40 +08:00
David Mak	2cfb7a7e10	core: Refactor range function into constructor	2024-07-09 04:44:40 +08:00
David Mak	9238a5e86e	standalone: Rename output_str to output_strln and add output_str output_str is for outputting strings without newline, and the newly introduced output_strln now has the old behavior of ending with a newline.	2024-07-09 04:44:40 +08:00
lyken	76defac462	meta: use clang -x c++ instead of clang++	2024-07-07 20:03:34 +08:00
lyken	650f354b74	core: use C++ for irrt source	2024-07-07 14:36:10 +08:00
abdul124	f062ef5f59	core/llvm_intrinsic: replace roundeven with rint	2024-07-07 14:24:18 +08:00
lyken	f52086b706	core: improve binop and cmpop error messages	2024-07-05 16:27:24 +08:00
lyken	0a732691c9	core: refactor typecheck/magic_methods.rs operators & add op symbol name	2024-07-05 16:27:20 +08:00
lyken	cbff356d50	core: workaround inkwell on `llvm.stackrestore`	2024-07-05 13:56:12 +08:00
lyken	24ac3820b2	core: check int32 obj_id directly in fold_numpy_function_call_shape_argument	2024-07-05 10:36:47 +08:00
David Mak	ba32fab374	standalone: Add demos for list arithmetic operators	2024-07-04 16:01:15 +08:00
David Mak	c4052b6342	core: Implement multi-operand __eq__ and __ne__ for lists	2024-07-04 16:01:15 +08:00
David Mak	66c205275f	core: Implement list::__add__	2024-07-04 16:01:11 +08:00
David Mak	c85e412206	core: Implement list::__mul__	2024-07-04 15:53:50 +08:00
David Mak	075536d7bd	core: Add BreakContinueHooks for gen_for_callback	2024-07-04 15:32:18 +08:00
David Mak	13beeaa2bf	core: Implement handling for zero-length lists	2024-07-04 15:32:18 +08:00
David Mak	2194dbddd5	core/type_annotation: Refactor List type to TObj In preparation for operators on lists.	2024-07-04 15:32:18 +08:00
David Mak	94a1d547d6	meta: Update dependencies	2024-07-04 15:32:18 +08:00
lyken	d6565feed3	core: ndarray_from_ndlist_impl cast size_of to usize	2024-07-04 12:24:52 +08:00
abdul124	83154ef8e1	core/llvm_intrinsics: remove llvm.roundeven call from call_float_roundeven	2024-07-03 14:17:47 +08:00
lyken	0744b938b8	core: fix __nac3_ndarray_calc_size crash due to incorrect typing	2024-07-03 13:03:14 +08:00
lyken	56fa2b6803	core: fix crash on iterating over non-iterables a	2024-06-28 15:45:53 +08:00
lyken	d06c13f936	core: fix crash on invalid subscripting	2024-06-27 16:58:48 +08:00
lyken	9808923258	core: improve comments in type_inferencer/mod.rs	2024-06-27 14:46:48 +08:00
lyken	5b11a1dbdd	core: support tuple and int32 input for np_empty, np_ones, and more	2024-06-27 14:30:17 +08:00
lyken	b21df53e0d	core: fix comment typo in unify_call()	2024-06-27 14:06:39 +08:00
lyken	0ec967a468	core: improve function call errors	2024-06-27 14:06:39 +08:00
lyken	ca8459dc7b	standalone: prettify TopLevelComposer error reporting	2024-06-27 10:15:14 +08:00
abdul124	b0b804051a	nac3artiq: allow class attribute access without init function	2024-06-25 16:06:33 +08:00
abdul124	134af79fd6	core: add support for class attributes	2024-06-25 16:06:33 +08:00
abdul124	7fe2c3496c	core: add attribute field to class definition	2024-06-25 16:06:33 +08:00