WIP

This reverts commit 308edb8237.

.clang-format

@@ -0,0 +1,32 @@
+BasedOnStyle: LLVM
+
+Language: Cpp
+Standard: Cpp11
+
+AccessModifierOffset: -1
+AlignEscapedNewlines: Left
+AlwaysBreakAfterReturnType: None
+AlwaysBreakTemplateDeclarations: Yes
+AllowAllParametersOfDeclarationOnNextLine: false
+AllowShortFunctionsOnASingleLine: Inline
+BinPackParameters: false
+BreakBeforeBinaryOperators: NonAssignment
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializers: AfterColon
+BreakInheritanceList: AfterColon
+ColumnLimit: 120
+ConstructorInitializerAllOnOneLineOrOnePerLine: true
+ContinuationIndentWidth: 4
+DerivePointerAlignment: false
+IndentCaseLabels: true
+IndentPPDirectives: None
+IndentWidth: 4
+MaxEmptyLinesToKeep: 1
+PointerAlignment: Left
+ReflowComments: true
+SortIncludes: false
+SortUsingDeclarations: true
+SpaceAfterTemplateKeyword: false
+SpacesBeforeTrailingComments: 2
+TabWidth: 4
+UseTab: Never

flake.nix

@@ -180,7 +180,9 @@
           clippy
           pre-commit
           rustfmt
+          rust-analyzer
         ];
+        RUST_SRC_PATH = "${pkgs.rust.packages.stable.rustPlatform.rustLibSrc}";
         shellHook =
           ''
           export DEMO_LINALG_STUB=${packages.x86_64-linux.demo-linalg-stub}/lib/liblinalg.a

nac3artiq/demo/demo.py

@@ -1,26 +1,87 @@
 from min_artiq import *
+from numpy import int32
 
 
+# @nac3
+# class A:
+#     a: int32
+#     core: KernelInvariant[Core]
+
+#     def __init__(self, a: int32):
+#         self.core = Core()
+#         self.a = a
+    
+#     @kernel
+#     def output_all_fields(self):
+#         #print(self.a)
+#         pass
+    
+#     @kernel
+#     def set_a(self, a: int32):
+#         self.a = a
+
+# @nac3
+# class B(A):
+#     b: int32
+
+#     def __init__(self, b: int32):
+#         # A.__init__(self, b + 1)
+#         self.core = Core()
+#         self.a = b
+#         self.b = b
+#         self.set_b(b)
+    
+#     @kernel
+#     def output_parent_fields(self):
+#         # A.output_all_fields(self)
+#         pass
+
+#     @kernel
+#     def output_all_fields(self):
+#         # A.output_all_fields(self)
+#         pass
+#         #print(self.b)
+    
+#     @kernel
+#     def set_b(self, b: int32):
+#         self.b = b
+
 @nac3
-class Demo:
+class C:
+    c: Kernel[int32]
+    a: Kernel[int32]
+    b: Kernel[int32]
     core: KernelInvariant[Core]
-    led0: KernelInvariant[TTLOut]
-    led1: KernelInvariant[TTLOut]
 
-    def __init__(self):
+    def __init__(self, c: int32):
+        # B.__init__(self, c + 1)
         self.core = Core()
-        self.led0 = TTLOut(self.core, 18)
+        self.a = c
-        self.led1 = TTLOut(self.core, 19)
+        self.b = c
+        self.c = c
+    
+    @kernel
+    def output_parent_fields(self):
+        # B.output_all_fields(self)
+        pass
+
+    @kernel
+    def output_all_fields(self):
+        # B.output_all_fields(self)
+        #print(self.c)
+        pass
+
+    @kernel
+    def set_c(self, c: int32):
+        self.c = c
     
     @kernel
     def run(self):
-        self.core.reset()
+        self.output_all_fields()
-        while True:
+        # self.set_a(1)
-            with parallel:
+        # self.set_b(2)
-                self.led0.pulse(100.*ms)
+        self.set_c(3)
-                self.led1.pulse(100.*ms)
+        self.output_all_fields()
-            self.core.delay(100.*ms)
-
 
 if __name__ == "__main__":
-    Demo().run()
+    C(10).run()

nac3artiq/src/lib.rs

@@ -557,6 +557,10 @@ impl Nac3 {
             .register_top_level(synthesized.pop().unwrap(), Some(resolver.clone()), "", false)
             .unwrap();
 
+        // Process IRRT
+        let context = inkwell::context::Context::create();
+        let irrt = load_irrt(&context, resolver.as_ref());
+
         let fun_signature =
             FunSignature { args: vec![], ret: self.primitive.none, vars: VarMap::new() };
         let mut store = ConcreteTypeStore::new();
@@ -727,7 +731,7 @@ impl Nac3 {
             membuffer.lock().push(buffer);
         });
 
-        let context = inkwell::context::Context::create();
+        // Link all modules into `main`.
         let buffers = membuffers.lock();
         let main = context
             .create_module_from_ir(MemoryBuffer::create_from_memory_range(&buffers[0], "main"))
@@ -756,8 +760,7 @@ impl Nac3 {
             )
             .unwrap();
 
-        main.link_in_module(load_irrt(&context))
+        main.link_in_module(irrt).map_err(|err| CompileError::new_err(err.to_string()))?;
-            .map_err(|err| CompileError::new_err(err.to_string()))?;
 
         let mut function_iter = main.get_first_function();
         while let Some(func) = function_iter {

nac3core/build.rs

@@ -8,37 +8,50 @@ use std::{
 };
 
 fn main() {
-    const FILE: &str = "src/codegen/irrt/irrt.cpp";
+    let out_dir = env::var("OUT_DIR").unwrap();
+    let out_dir = Path::new(&out_dir);
+    let irrt_dir = Path::new("irrt");
+
+    let irrt_cpp_path = irrt_dir.join("irrt.cpp");
 
     /*
      * HACK: Sadly, clang doesn't let us emit generic LLVM bitcode.
      * Compiling for WASM32 and filtering the output with regex is the closest we can get.
      */
-    let flags: &[&str] = &[
+    let mut flags: Vec<&str> = vec![
         "--target=wasm32",
-        FILE,
         "-x",
         "c++",
+        "-std=c++20",
         "-fno-discard-value-names",
         "-fno-exceptions",
         "-fno-rtti",
-        match env::var("PROFILE").as_deref() {
-            Ok("debug") => "-O0",
-            Ok("release") => "-O3",
-            flavor => panic!("Unknown or missing build flavor {flavor:?}"),
-        },
         "-emit-llvm",
         "-S",
         "-Wall",
         "-Wextra",
         "-o",
         "-",
+        "-I",
+        irrt_dir.to_str().unwrap(),
+        irrt_cpp_path.to_str().unwrap(),
     ];
 
-    println!("cargo:rerun-if-changed={FILE}");
+    match env::var("PROFILE").as_deref() {
-    let out_dir = env::var("OUT_DIR").unwrap();
+        Ok("debug") => {
-    let out_path = Path::new(&out_dir);
+            flags.push("-O0");
+            flags.push("-DIRRT_DEBUG_ASSERT");
+        }
+        Ok("release") => {
+            flags.push("-O3");
+        }
+        flavor => panic!("Unknown or missing build flavor {flavor:?}"),
+    }
 
+    // Tell Cargo to rerun if any file under `irrt_dir` (recursive) changes
+    println!("cargo:rerun-if-changed={}", irrt_dir.to_str().unwrap());
+
+    // Compile IRRT and capture the LLVM IR output
     let output = Command::new("clang-irrt")
         .args(flags)
         .output()
@@ -52,7 +65,17 @@ 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();
+    // Filter out irrelevant IR
+    //
+    // Regex:
+    // - `(?ms:^define.*?\}$)` captures LLVM `define` blocks
+    // - `(?m:^declare.*?$)` captures LLVM `declare` lines
+    // - `(?m:^%.+?=\s*type\s*\{.+?\}$)` captures LLVM `type` declarations
+    // - `(?m:^@.+?=.+$)` captures global constants
+    let regex_filter = Regex::new(
+        r"(?ms:^define.*?\}$)|(?m:^declare.*?$)|(?m:^%.+?=\s*type\s*\{.+?\}$)|(?m:^@.+?=.+$)",
+    )
+    .unwrap();
     for f in regex_filter.captures_iter(&output) {
         assert_eq!(f.len(), 1);
         filtered_output.push_str(&f[0]);
@@ -63,18 +86,22 @@ fn main() {
         .unwrap()
         .replace_all(&filtered_output, "");
 
-    println!("cargo:rerun-if-env-changed=DEBUG_DUMP_IRRT");
+    // For debugging
-    if env::var("DEBUG_DUMP_IRRT").is_ok() {
+    // Doing `DEBUG_DUMP_IRRT=1 cargo build -p nac3core` dumps the LLVM IR generated
-        let mut file = File::create(out_path.join("irrt.ll")).unwrap();
+    const DEBUG_DUMP_IRRT: &str = "DEBUG_DUMP_IRRT";
+    println!("cargo:rerun-if-env-changed={DEBUG_DUMP_IRRT}");
+    if env::var(DEBUG_DUMP_IRRT).is_ok() {
+        let mut file = File::create(out_dir.join("irrt.ll")).unwrap();
         file.write_all(output.as_bytes()).unwrap();
-        let mut file = File::create(out_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();

nac3core/irrt/irrt.cpp

@@ -0,0 +1,6 @@
+#include <irrt/exception.hpp>
+#include <irrt/int_types.hpp>
+#include <irrt/list.hpp>
+#include <irrt/math.hpp>
+#include <irrt/ndarray.hpp>
+#include <irrt/slice.hpp>

nac3core/irrt/irrt/cslice.hpp

@@ -0,0 +1,9 @@
+#pragma once
+
+#include <irrt/int_types.hpp>
+
+template<typename SizeT>
+struct CSlice {
+    uint8_t* base;
+    SizeT len;
+};

nac3core/irrt/irrt/debug.hpp

@@ -0,0 +1,25 @@
+#pragma once
+
+// Set in nac3core/build.rs
+#ifdef IRRT_DEBUG_ASSERT
+#define IRRT_DEBUG_ASSERT_BOOL true
+#else
+#define IRRT_DEBUG_ASSERT_BOOL false
+#endif
+
+#define raise_debug_assert(SizeT, msg, param1, param2, param3) \
+    raise_exception(SizeT, EXN_ASSERTION_ERROR, "IRRT debug assert failed: " msg, param1, param2, param3)
+
+#define debug_assert_eq(SizeT, lhs, rhs)                                           \
+    if constexpr (IRRT_DEBUG_ASSERT_BOOL) {                                        \
+        if ((lhs) != (rhs)) {                                                      \
+            raise_debug_assert(SizeT, "LHS = {0}. RHS = {1}", lhs, rhs, NO_PARAM); \
+        }                                                                          \
+    }
+
+#define debug_assert(SizeT, expr)                                                  \
+    if constexpr (IRRT_DEBUG_ASSERT_BOOL) {                                        \
+        if (!(expr)) {                                                             \
+            raise_debug_assert(SizeT, "Got false.", NO_PARAM, NO_PARAM, NO_PARAM); \
+        }                                                                          \
+    }

nac3core/irrt/irrt/exception.hpp

@@ -0,0 +1,82 @@
+#pragma once
+
+#include <irrt/cslice.hpp>
+#include <irrt/int_types.hpp>
+
+/**
+ * @brief The int type of ARTIQ exception IDs.
+ */
+typedef int32_t ExceptionId;
+
+/*
+ * Set of exceptions C++ IRRT can use.
+ * Must be synchronized with `setup_irrt_exceptions` in `nac3core/src/codegen/irrt/mod.rs`.
+ */
+extern "C" {
+ExceptionId EXN_INDEX_ERROR;
+ExceptionId EXN_VALUE_ERROR;
+ExceptionId EXN_ASSERTION_ERROR;
+ExceptionId EXN_TYPE_ERROR;
+}
+
+/**
+ * @brief Extern function to `__nac3_raise`
+ *
+ * The parameter `err` could be `Exception<int32_t>` or `Exception<int64_t>`. The caller
+ * must make sure to pass `Exception`s with the correct `SizeT` depending on the `size_t` of the runtime.
+ */
+extern "C" void __nac3_raise(void* err);
+
+namespace {
+/**
+ * @brief NAC3's Exception struct
+ */
+template<typename SizeT>
+struct Exception {
+    ExceptionId id;
+    CSlice<SizeT> filename;
+    int32_t line;
+    int32_t column;
+    CSlice<SizeT> function;
+    CSlice<SizeT> msg;
+    int64_t params[3];
+};
+
+constexpr int64_t NO_PARAM = 0;
+
+template<typename SizeT>
+void _raise_exception_helper(ExceptionId id,
+                             const char* filename,
+                             int32_t line,
+                             const char* function,
+                             const char* msg,
+                             int64_t param0,
+                             int64_t param1,
+                             int64_t param2) {
+    Exception<SizeT> e = {
+        .id = id,
+        .filename = {.base = reinterpret_cast<const uint8_t*>(filename), .len = __builtin_strlen(filename)},
+        .line = line,
+        .column = 0,
+        .function = {.base = reinterpret_cast<const uint8_t*>(function), .len = __builtin_strlen(function)},
+        .msg = {.base = reinterpret_cast<const uint8_t*>(msg), .len = __builtin_strlen(msg)},
+    };
+    e.params[0] = param0;
+    e.params[1] = param1;
+    e.params[2] = param2;
+    __nac3_raise(reinterpret_cast<void*>(&e));
+    __builtin_unreachable();
+}
+
+/**
+ * @brief Raise an exception with location details (location in the IRRT source files).
+ * @param SizeT The runtime `size_t` type.
+ * @param id The ID of the exception to raise.
+ * @param msg A global constant C-string of the error message.
+ *
+ * `param0` to `param2` are optional format arguments of `msg`. They should be set to
+ * `NO_PARAM` to indicate they are unused.
+ */
+#define raise_exception(SizeT, id, msg, param0, param1, param2) \
+    _raise_exception_helper<SizeT>(id, __FILE__, __LINE__, __FUNCTION__, msg, param0, param1, param2)
+}  // namespace

nac3core/irrt/irrt/int_types.hpp

@@ -0,0 +1,13 @@
+#pragma once
+
+using int8_t = _BitInt(8);
+using uint8_t = unsigned _BitInt(8);
+using int32_t = _BitInt(32);
+using uint32_t = unsigned _BitInt(32);
+using int64_t = _BitInt(64);
+using uint64_t = unsigned _BitInt(64);
+
+// NDArray indices are always `uint32_t`.
+using NDIndex = uint32_t;
+// The type of an index or a value describing the length of a range/slice is always `int32_t`.
+using SliceIndex = int32_t;

nac3core/irrt/irrt/list.hpp

@@ -0,0 +1,75 @@
+#pragma once
+
+#include <irrt/int_types.hpp>
+#include <irrt/math_util.hpp>
+
+extern "C" {
+// 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;
+}
+}  // extern "C"

nac3core/irrt/irrt/math.hpp

@@ -0,0 +1,93 @@
+#pragma once
+
+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;
+}
+}  // namespace
+
+#define DEF_nac3_int_exp_(T)                   \
+    T __nac3_int_exp_##T(T base, T exp) {      \
+        return __nac3_int_exp_impl(base, exp); \
+    }
+
+extern "C" {
+
+// Putting semicolons here to make clang-format not reformat this into
+// a stair shape.
+DEF_nac3_int_exp_(int32_t);
+DEF_nac3_int_exp_(int64_t);
+DEF_nac3_int_exp_(uint32_t);
+DEF_nac3_int_exp_(uint64_t);
+
+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);
+}
+}

nac3core/irrt/irrt/math_util.hpp

@@ -0,0 +1,13 @@
+#pragma once
+
+namespace {
+template<typename T>
+const T& max(const T& a, const T& b) {
+    return a > b ? a : b;
+}
+
+template<typename T>
+const T& min(const T& a, const T& b) {
+    return a > b ? b : a;
+}
+}  // namespace

nac3core/irrt/irrt/ndarray.hpp

@@ -0,0 +1,144 @@
+#pragma once
+
+#include <irrt/int_types.hpp>
+
+namespace {
+template<typename SizeT>
+SizeT __nac3_ndarray_calc_size_impl(const SizeT* list_data, SizeT list_len, SizeT begin_idx, SizeT end_idx) {
+    __builtin_assume(end_idx <= list_len);
+
+    SizeT num_elems = 1;
+    for (SizeT i = begin_idx; i < end_idx; ++i) {
+        SizeT val = list_data[i];
+        __builtin_assume(val > 0);
+        num_elems *= val;
+    }
+    return num_elems;
+}
+
+template<typename SizeT>
+void __nac3_ndarray_calc_nd_indices_impl(SizeT index, const SizeT* dims, SizeT num_dims, 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>
+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>
+void __nac3_ndarray_calc_broadcast_impl(const SizeT* lhs_dims,
+                                        SizeT lhs_ndims,
+                                        const SizeT* rhs_dims,
+                                        SizeT rhs_ndims,
+                                        SizeT* out_dims) {
+    SizeT max_ndims = lhs_ndims > rhs_ndims ? lhs_ndims : rhs_ndims;
+
+    for (SizeT i = 0; i < max_ndims; ++i) {
+        const SizeT* lhs_dim_sz = i < lhs_ndims ? &lhs_dims[lhs_ndims - i - 1] : nullptr;
+        const SizeT* rhs_dim_sz = i < rhs_ndims ? &rhs_dims[rhs_ndims - i - 1] : nullptr;
+        SizeT* out_dim = &out_dims[max_ndims - i - 1];
+
+        if (lhs_dim_sz == nullptr) {
+            *out_dim = *rhs_dim_sz;
+        } else if (rhs_dim_sz == nullptr) {
+            *out_dim = *lhs_dim_sz;
+        } else if (*lhs_dim_sz == 1) {
+            *out_dim = *rhs_dim_sz;
+        } else if (*rhs_dim_sz == 1) {
+            *out_dim = *lhs_dim_sz;
+        } else if (*lhs_dim_sz == *rhs_dim_sz) {
+            *out_dim = *lhs_dim_sz;
+        } else {
+            __builtin_unreachable();
+        }
+    }
+}
+
+template<typename SizeT>
+void __nac3_ndarray_calc_broadcast_idx_impl(const SizeT* src_dims,
+                                            SizeT src_ndims,
+                                            const 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];
+    }
+}
+}  // namespace
+
+extern "C" {
+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);
+}
+}

nac3core/irrt/irrt/slice.hpp

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <irrt/int_types.hpp>
+
+extern "C" {
+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;
+    }
+}
+}

nac3core/src/codegen/irrt/irrt.cpp

@@ -1,414 +0,0 @@
-using int8_t = _BitInt(8);
-using uint8_t = unsigned _BitInt(8);
-using int32_t = _BitInt(32);
-using uint32_t = unsigned _BitInt(32);
-using int64_t = _BitInt(64);
-using uint64_t = unsigned _BitInt(64);
-
-// NDArray indices are always `uint32_t`.
-using NDIndex = uint32_t;
-// The type of an index or a value describing the length of a range/slice is always `int32_t`.
-using SliceIndex = int32_t;
-
-namespace {
-template <typename T>
-const T& max(const T& a, const T& b) {
-    return a > b ? a : b;
-}
-
-template <typename T>
-const T& min(const T& a, const T& b) {
-    return a > b ? b : a;
-}
-
-// adapted from GNU Scientific Library: https://git.savannah.gnu.org/cgit/gsl.git/tree/sys/pow_int.c
-// need to make sure `exp >= 0` before calling this function
-template <typename T>
-T __nac3_int_exp_impl(T base, T exp) {
-    T res = 1;
-    /* repeated squaring method */
-    do {
-        if (exp & 1) {
-            res *= base; /* for n odd */
-        }
-        exp >>= 1;
-        base *= base;
-    } while (exp);
-    return res;
-}
-
-template <typename SizeT>
-SizeT __nac3_ndarray_calc_size_impl(
-    const SizeT* list_data,
-    SizeT list_len,
-    SizeT begin_idx,
-    SizeT end_idx
-) {
-    __builtin_assume(end_idx <= list_len);
-
-    SizeT num_elems = 1;
-    for (SizeT i = begin_idx; i < end_idx; ++i) {
-        SizeT val = list_data[i];
-        __builtin_assume(val > 0);
-        num_elems *= val;
-    }
-    return num_elems;
-}
-
-template <typename SizeT>
-void __nac3_ndarray_calc_nd_indices_impl(
-    SizeT index,
-    const SizeT* dims,
-    SizeT num_dims,
-    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>
-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>
-void __nac3_ndarray_calc_broadcast_impl(
-    const SizeT* lhs_dims,
-    SizeT lhs_ndims,
-    const SizeT* rhs_dims,
-    SizeT rhs_ndims,
-    SizeT* out_dims
-) {
-    SizeT max_ndims = lhs_ndims > rhs_ndims ? lhs_ndims : rhs_ndims;
-
-    for (SizeT i = 0; i < max_ndims; ++i) {
-        const SizeT* lhs_dim_sz = i < lhs_ndims ? &lhs_dims[lhs_ndims - i - 1] : nullptr;
-        const SizeT* rhs_dim_sz = i < rhs_ndims ? &rhs_dims[rhs_ndims - i - 1] : nullptr;
-        SizeT* out_dim = &out_dims[max_ndims - i - 1];
-
-        if (lhs_dim_sz == nullptr) {
-            *out_dim = *rhs_dim_sz;
-        } else if (rhs_dim_sz == nullptr) {
-            *out_dim = *lhs_dim_sz;
-        } else if (*lhs_dim_sz == 1) {
-            *out_dim = *rhs_dim_sz;
-        } else if (*rhs_dim_sz == 1) {
-            *out_dim = *lhs_dim_sz;
-        } else if (*lhs_dim_sz == *rhs_dim_sz) {
-            *out_dim = *lhs_dim_sz;
-        } else {
-            __builtin_unreachable();
-        }
-    }
-}
-
-template <typename SizeT>
-void __nac3_ndarray_calc_broadcast_idx_impl(
-    const SizeT* src_dims,
-    SizeT src_ndims,
-    const 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];
-    }
-}
-}  // namespace
-
-extern "C" {
-#define DEF_nac3_int_exp_(T) \
-    T __nac3_int_exp_##T(T base, T exp) {\
-        return __nac3_int_exp_impl(base, exp);\
-    }
-
-DEF_nac3_int_exp_(int32_t)
-DEF_nac3_int_exp_(int64_t)
-DEF_nac3_int_exp_(uint32_t)
-DEF_nac3_int_exp_(uint64_t)
-
-SliceIndex __nac3_slice_index_bound(SliceIndex i, const SliceIndex len) {
-    if (i < 0) {
-        i = len + i;
-    }
-    if (i < 0) {
-        return 0;
-    } else if (i > len) {
-        return len;
-    }
-    return i;
-}
-
-SliceIndex __nac3_range_slice_len(
-    const SliceIndex start,
-    const SliceIndex end,
-    const SliceIndex step
-) {
-    SliceIndex diff = end - start;
-    if (diff > 0 && step > 0) {
-        return ((diff - 1) / step) + 1;
-    } else if (diff < 0 && step < 0) {
-        return ((diff + 1) / step) + 1;
-    } else {
-        return 0;
-    }
-}
-
-// Handle list assignment and dropping part of the list when
-// both dest_step and src_step are +1.
-// - All the index must *not* be out-of-bound or negative,
-// - The end index is *inclusive*,
-// - The length of src and dest slice size should already
-// be checked: if dest.step == 1 then len(src) <= len(dest) else len(src) == len(dest)
-SliceIndex __nac3_list_slice_assign_var_size(
-    SliceIndex dest_start,
-    SliceIndex dest_end,
-    SliceIndex dest_step,
-    uint8_t* dest_arr,
-    SliceIndex dest_arr_len,
-    SliceIndex src_start,
-    SliceIndex src_end,
-    SliceIndex src_step,
-    uint8_t* src_arr,
-    SliceIndex src_arr_len,
-    const SliceIndex size
-) {
-    /* if dest_arr_len == 0, do nothing since we do not support extending list */
-    if (dest_arr_len == 0) return dest_arr_len;
-    /* if both step is 1, memmove directly, handle the dropping of the list, and shrink size */
-    if (src_step == dest_step && dest_step == 1) {
-        const SliceIndex src_len = (src_end >= src_start) ? (src_end - src_start + 1) : 0;
-        const SliceIndex dest_len = (dest_end >= dest_start) ? (dest_end - dest_start + 1) : 0;
-        if (src_len > 0) {
-            __builtin_memmove(
-                dest_arr + dest_start * size,
-                src_arr + src_start * size,
-                src_len * size
-            );
-        }
-        if (dest_len > 0) {
-            /* dropping */
-            __builtin_memmove(
-                dest_arr + (dest_start + src_len) * size,
-                dest_arr + (dest_end + 1) * size,
-                (dest_arr_len - dest_end - 1) * size
-            );
-        }
-        /* shrink size */
-        return dest_arr_len - (dest_len - src_len);
-    }
-    /* if two range overlaps, need alloca */
-    uint8_t need_alloca =
-        (dest_arr == src_arr)
-        && !(
-            max(dest_start, dest_end) < min(src_start, src_end)
-            || max(src_start, src_end) < min(dest_start, dest_end)
-        );
-    if (need_alloca) {
-        uint8_t* tmp = reinterpret_cast<uint8_t *>(__builtin_alloca(src_arr_len * size));
-        __builtin_memcpy(tmp, src_arr, src_arr_len * size);
-        src_arr = tmp;
-    }
-    SliceIndex src_ind = src_start;
-    SliceIndex dest_ind = dest_start;
-    for (;
-        (src_step > 0) ? (src_ind <= src_end) : (src_ind >= src_end);
-        src_ind += src_step, dest_ind += dest_step
-    ) {
-        /* for constant optimization */
-        if (size == 1) {
-            __builtin_memcpy(dest_arr + dest_ind, src_arr + src_ind, 1);
-        } else if (size == 4) {
-            __builtin_memcpy(dest_arr + dest_ind * 4, src_arr + src_ind * 4, 4);
-        } else if (size == 8) {
-            __builtin_memcpy(dest_arr + dest_ind * 8, src_arr + src_ind * 8, 8);
-        } else {
-            /* memcpy for var size, cannot overlap after previous alloca */
-            __builtin_memcpy(dest_arr + dest_ind * size, src_arr + src_ind * size, size);
-        }
-    }
-    /* only dest_step == 1 can we shrink the dest list. */
-    /* size should be ensured prior to calling this function */
-    if (dest_step == 1 && dest_end >= dest_start) {
-        __builtin_memmove(
-            dest_arr + dest_ind * size,
-            dest_arr + (dest_end + 1) * size,
-            (dest_arr_len - dest_end - 1) * size
-        );
-        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);
-}
-}  // extern "C"

nac3core/src/codegen/irrt/mod.rs

@@ -1,4 +1,4 @@
-use crate::typecheck::typedef::Type;
+use crate::{symbol_resolver::SymbolResolver, typecheck::typedef::Type};
 
 use super::{
     classes::{
@@ -16,14 +16,14 @@ use inkwell::{
     memory_buffer::MemoryBuffer,
     module::Module,
     types::{BasicTypeEnum, IntType},
-    values::{BasicValueEnum, CallSiteValue, FloatValue, IntValue},
+    values::{BasicValue, BasicValueEnum, CallSiteValue, FloatValue, IntValue},
     AddressSpace, IntPredicate,
 };
 use itertools::Either;
 use nac3parser::ast::Expr;
 
 #[must_use]
-pub fn load_irrt(ctx: &Context) -> Module {
+pub fn load_irrt<'ctx>(ctx: &'ctx Context, symbol_resolver: &dyn SymbolResolver) -> Module<'ctx> {
     let bitcode_buf = MemoryBuffer::create_from_memory_range(
         include_bytes!(concat!(env!("OUT_DIR"), "/irrt.bc")),
         "irrt_bitcode_buffer",
@@ -39,6 +39,25 @@ pub fn load_irrt(ctx: &Context) -> Module {
         let function = irrt_mod.get_function(symbol).unwrap();
         function.add_attribute(AttributeLoc::Function, ctx.create_enum_attribute(inline_attr, 0));
     }
+
+    // Initialize all global `EXN_*` exception IDs in IRRT with the [`SymbolResolver`].
+    let exn_id_type = ctx.i32_type();
+    let errors = &[
+        ("EXN_INDEX_ERROR", "0:IndexError"),
+        ("EXN_VALUE_ERROR", "0:ValueError"),
+        ("EXN_ASSERTION_ERROR", "0:AssertionError"),
+        ("EXN_TYPE_ERROR", "0:TypeError"),
+    ];
+    for (irrt_name, symbol_name) in errors {
+        let exn_id = symbol_resolver.get_string_id(symbol_name);
+        let exn_id = exn_id_type.const_int(exn_id as u64, false).as_basic_value_enum();
+
+        let global = irrt_mod.get_global(irrt_name).unwrap_or_else(|| {
+            panic!("Exception symbol name '{irrt_name}' should exist in the IRRT LLVM module")
+        });
+        global.set_initializer(&exn_id);
+    }
+
     irrt_mod
 }
 

nac3core/src/toplevel/composer.rs

@@ -1,3 +1,4 @@
+use indexmap::IndexMap;
 use nac3parser::ast::fold::Fold;
 use std::rc::Rc;
 
@@ -5,7 +6,7 @@ use crate::{
     codegen::{expr::get_subst_key, stmt::exn_constructor},
     symbol_resolver::SymbolValue,
     typecheck::{
-        type_inferencer::{FunctionData, Inferencer},
+        type_inferencer::{report_error, FunctionData, Inferencer},
         typedef::{TypeVar, VarMap},
     },
 };
@@ -389,8 +390,15 @@ impl TopLevelComposer {
     }
 
     pub fn start_analysis(&mut self, inference: bool) -> Result<(), HashSet<String>> {
-        self.analyze_top_level_class_type_var()?;
+        let unifier = self.unifier.borrow_mut();
-        self.analyze_top_level_class_bases()?;
+        let primitives_store = &self.primitives_ty;
+        let def_list = &self.definition_ast_list;
+
+        // Step 1. Analyze type variables within class definitions
+        Self::analyze_top_level_class_type_var2(def_list, unifier, primitives_store, (&self.keyword_list, &self.core_config))?;
+
+        // self.analyze_top_level_class_type_var()?;
+        // self.analyze_top_level_class_bases()?;
         self.analyze_top_level_class_fields_methods()?;
         self.analyze_top_level_function()?;
         if inference {
@@ -399,178 +407,70 @@ impl TopLevelComposer {
         Ok(())
     }
 
-    /// step 1, analyze the type vars associated with top level class
+    fn analyze_bases(
-    fn analyze_top_level_class_type_var(&mut self) -> Result<(), HashSet<String>> {
+        class_def: &Arc<RwLock<TopLevelDef>>,
-        let def_list = &self.definition_ast_list;
+        class_ast: &Option<Stmt>,
-        let temp_def_list = self.extract_def_list();
+        temp_def_list: &[Arc<RwLock<TopLevelDef>>],
-        let unifier = self.unifier.borrow_mut();
+        unifier: &mut Unifier,
-        let primitives_store = &self.primitives_ty;
+        primitives_store: &PrimitiveStore,
-
+    ) -> Result<(), HashSet<String>> {
-        let mut analyze = |class_def: &Arc<RwLock<TopLevelDef>>, class_ast: &Option<Stmt>| {
+        let mut class_def = class_def.write();
-            // only deal with class def here
+        let (class_def_id, class_ancestors, class_bases_ast, class_type_vars, class_resolver) = {
-            let mut class_def = class_def.write();
+            let TopLevelDef::Class { object_id, ancestors, type_vars, resolver, .. } =
-            let (class_bases_ast, class_def_type_vars, class_resolver) = {
+                &mut *class_def
-                if let TopLevelDef::Class { type_vars, resolver, .. } = &mut *class_def {
+            else {
-                    let Some(ast::Located { node: ast::StmtKind::ClassDef { bases, .. }, .. }) =
+                unreachable!()
-                        class_ast
-                    else {
-                        unreachable!()
-                    };
-
-                    (bases, type_vars, resolver)
-                } else {
-                    return Ok(());
-                }
             };
-            let class_resolver = class_resolver.as_ref().unwrap();
+            let Some(ast::Located { node: ast::StmtKind::ClassDef { bases, .. }, .. }) = class_ast
-            let class_resolver = &**class_resolver;
+            else {
-
+                unreachable!()
-            let mut is_generic = false;
+            };
-            for b in class_bases_ast {
+            (object_id, ancestors, bases, type_vars, resolver.as_ref().unwrap().as_ref())
-                match &b.node {
-                    // analyze typevars bounded to the class,
-                    // only support things like `class A(Generic[T, V])`,
-                    // things like `class A(Generic[T, V, ImportedModule.T])` is not supported
-                    // i.e. only simple names are allowed in the subscript
-                    // should update the TopLevelDef::Class.typevars and the TypeEnum::TObj.params
-                    ast::ExprKind::Subscript { value, slice, .. }
-                        if {
-                            matches!(
-                                &value.node,
-                                ast::ExprKind::Name { id, .. } if id == &"Generic".into()
-                            )
-                        } =>
-                    {
-                        if is_generic {
-                            return Err(HashSet::from([format!(
-                                "only single Generic[...] is allowed (at {})",
-                                b.location
-                            )]));
-                        }
-                        is_generic = true;
-
-                        let type_var_list: Vec<&ast::Expr<()>>;
-                        // if `class A(Generic[T, V, G])`
-                        if let ast::ExprKind::Tuple { elts, .. } = &slice.node {
-                            type_var_list = elts.iter().collect_vec();
-                        // `class A(Generic[T])`
-                        } else {
-                            type_var_list = vec![&**slice];
-                        }
-
-                        // parse the type vars
-                        let type_vars = type_var_list
-                            .into_iter()
-                            .map(|e| {
-                                class_resolver.parse_type_annotation(
-                                    &temp_def_list,
-                                    unifier,
-                                    primitives_store,
-                                    e,
-                                )
-                            })
-                            .collect::<Result<Vec<_>, _>>()?;
-
-                        // check if all are unique type vars
-                        let all_unique_type_var = {
-                            let mut occurred_type_var_id: HashSet<TypeVarId> = HashSet::new();
-                            type_vars.iter().all(|x| {
-                                let ty = unifier.get_ty(*x);
-                                if let TypeEnum::TVar { id, .. } = ty.as_ref() {
-                                    occurred_type_var_id.insert(*id)
-                                } else {
-                                    false
-                                }
-                            })
-                        };
-                        if !all_unique_type_var {
-                            return Err(HashSet::from([format!(
-                                "duplicate type variable occurs (at {})",
-                                slice.location
-                            )]));
-                        }
-
-                        // add to TopLevelDef
-                        class_def_type_vars.extend(type_vars);
-                    }
-
-                    // if others, do nothing in this function
-                    _ => continue,
-                }
-            }
-            Ok(())
         };
-        let mut errors = HashSet::new();
-        for (class_def, class_ast) in def_list.iter().skip(self.builtin_num) {
-            if class_ast.is_none() {
-                continue;
-            }
-            if let Err(e) = analyze(class_def, class_ast) {
-                errors.extend(e);
-            }
-        }
-        if !errors.is_empty() {
-            return Err(errors);
-        }
-        Ok(())
-    }
 
-    /// step 2, base classes.
+        let mut is_generic = false;
-    /// now that the type vars of all classes are done, handle base classes and
+        let mut has_base = false;
-    /// put Self class into the ancestors list. We only allow single inheritance
+        // Check class bases for typevars
-    fn analyze_top_level_class_bases(&mut self) -> Result<(), HashSet<String>> {
+        for b in class_bases_ast {
-        if self.unifier.top_level.is_none() {
+            match &b.node {
-            let ctx = Arc::new(self.make_top_level_context());
+                // analyze typevars bounded to the class,
-            self.unifier.top_level = Some(ctx);
+                // only support things like `class A(Generic[T, V])`,
-        }
+                // things like `class A(Generic[T, V, ImportedModule.T])` is not supported
+                // i.e. only simple names are allowed in the subscript
+                // should update the TopLevelDef::Class.typevars and the TypeEnum::TObj.params
+                ast::ExprKind::Subscript { value, slice, .. } if matches!(&value.node, ast::ExprKind::Name { id, .. } if id == &"Generic".into()) =>
+                {
+                    if is_generic {
+                        return report_error("only single Generic[...] is allowed", b.location);
+                    }
+                    is_generic = true;
 
-        let temp_def_list = self.extract_def_list();
+                    let type_var_list: Vec<&ast::Expr<()>>;
-        let unifier = self.unifier.borrow_mut();
+                    // if `class A(Generic[T, V, G])`
-        let primitive_types = self.primitives_ty;
+                    if let ast::ExprKind::Tuple { elts, .. } = &slice.node {
-
+                        type_var_list = elts.iter().collect_vec();
-        let mut get_direct_parents =
+                    // `class A(Generic[T])`
-            |class_def: &Arc<RwLock<TopLevelDef>>, class_ast: &Option<Stmt>| {
-                let mut class_def = class_def.write();
-                let (class_def_id, class_bases, class_ancestors, class_resolver, class_type_vars) = {
-                    if let TopLevelDef::Class {
-                        ancestors, resolver, object_id, type_vars, ..
-                    } = &mut *class_def
-                    {
-                        let Some(ast::Located {
-                            node: ast::StmtKind::ClassDef { bases, .. }, ..
-                        }) = class_ast
-                        else {
-                            unreachable!()
-                        };
-
-                        (object_id, bases, ancestors, resolver, type_vars)
                     } else {
-                        return Ok(());
+                        type_var_list = vec![&**slice];
                     }
-                };
-                let class_resolver = class_resolver.as_ref().unwrap();
-                let class_resolver = &**class_resolver;
 
-                let mut has_base = false;
+                    let type_vars = type_var_list
-                for b in class_bases {
+                        .into_iter()
-                    // type vars have already been handled, so skip on `Generic[...]`
+                        .map(|e| {
-                    if matches!(
+                            class_resolver.parse_type_annotation(
-                        &b.node,
+                                temp_def_list,
-                        ast::ExprKind::Subscript { value, .. }
+                                unifier,
-                            if matches!(
+                                primitives_store,
-                                &value.node,
+                                e,
-                                ast::ExprKind::Name { id, .. } if id == &"Generic".into()
                             )
-                    ) {
+                        })
-                        continue;
+                        .collect::<Result<Vec<_>, _>>()?;
-                    }
 
+                    class_type_vars.extend(type_vars);
+                }
+                ast::ExprKind::Name { .. } => {
                     if has_base {
-                        return Err(HashSet::from([format!(
+                        return report_error("a class definition can only have at most one base class declaration and one generic declaration", b.location);
-                            "a class definition can only have at most one base class \
-                                declaration and one generic declaration (at {})",
-                            b.location
-                        )]));
                     }
                     has_base = true;
 
@@ -578,9 +478,9 @@ impl TopLevelComposer {
                     // bast_ty if it is a CustomClassKind
                     let base_ty = parse_ast_to_type_annotation_kinds(
                         class_resolver,
-                        &temp_def_list,
+                        temp_def_list,
                         unifier,
-                        &primitive_types,
+                        primitives_store,
                         b,
                         vec![(*class_def_id, class_type_vars.clone())]
                             .into_iter()
@@ -590,123 +490,127 @@ impl TopLevelComposer {
                     if let TypeAnnotation::CustomClass { .. } = &base_ty {
                         class_ancestors.push(base_ty);
                     } else {
-                        return Err(HashSet::from([format!(
+                        return report_error(
-                            "class base declaration can only be custom class (at {})",
+                            "class base declaration can only be custom class",
                             b.location,
-                        )]));
+                        );
                     }
                 }
-                Ok(())
+                // TODO: Report Error here
-            };
+                _ => {
+                    println!("Type was => {}", b.node.name());
+                }
+            }
+        }
 
-        // first, only push direct parent into the list
+        Ok(())
+    }
+
+    fn analyze_ancestors(
+        class_def: &Arc<RwLock<TopLevelDef>>,
+        temp_def_list: &[Arc<RwLock<TopLevelDef>>],
+    ) {
+        // Check if class has a direct parent
+        let mut class_def = class_def.write();
+        let TopLevelDef::Class { ancestors, type_vars, object_id, .. } = &mut *class_def else {
+            unreachable!()
+        };
+        let mut anc_set = HashMap::new();
+
+        if let Some(ancestor) = ancestors.first() {
+            let TypeAnnotation::CustomClass { id, .. } = ancestor else { unreachable!() };
+            let TopLevelDef::Class { ancestors: parent_ancestors, .. } =
+                &*temp_def_list[id.0].read()
+            else {
+                unreachable!()
+            };
+            for anc in parent_ancestors.iter().skip(1) {
+                let TypeAnnotation::CustomClass { id, .. } = anc else { unreachable!() };
+                anc_set.insert(id, anc.clone());
+            }
+            ancestors.extend(anc_set.into_iter().map(|f| f.1).collect::<Vec<_>>());
+        }
+
+        ancestors.insert(0, make_self_type_annotation(type_vars.as_slice(), *object_id));
+    }
+
+    /// step 1, analyze the type vars associated with top level class
+    fn analyze_top_level_class_type_var2(
+        def_list: &[DefAst],
+        unifier: &mut Unifier,
+        primitives_store: &PrimitiveStore,
+        core_info: (&HashSet<StrRef>, &ComposerConfig),
+    ) -> Result<(), HashSet<String>> {
         let mut errors = HashSet::new();
-        for (class_def, class_ast) in self.definition_ast_list.iter_mut().skip(self.builtin_num) {
+        let mut temp_def_list: Vec<Arc<RwLock<TopLevelDef>>> = Vec::default();
-            if class_ast.is_none() {
-                continue;
-            }
-            if let Err(e) = get_direct_parents(class_def, class_ast) {
-                errors.extend(e);
-            }
-        }
-        if !errors.is_empty() {
-            return Err(errors);
-        }
 
-        // second, get all ancestors
+        for (class_def, class_ast) in def_list {
-        let mut ancestors_store: HashMap<DefinitionId, Vec<TypeAnnotation>> = HashMap::default();
+            if class_ast.is_some() && matches!(&*class_def.read(), TopLevelDef::Class { .. }) {
-        let mut get_all_ancestors =
+                // Add type vars and direct parents
-            |class_def: &Arc<RwLock<TopLevelDef>>| -> Result<(), HashSet<String>> {
+                if let Err(e) = Self::analyze_bases(
-                let class_def = class_def.read();
+                    class_def,
-                let (class_ancestors, class_id) = {
+                    class_ast,
-                    if let TopLevelDef::Class { ancestors, object_id, .. } = &*class_def {
+                    &temp_def_list,
-                        (ancestors, *object_id)
+                    unifier,
-                    } else {
+                    primitives_store,
-                        return Ok(());
+                ) {
-                    }
+                    errors.extend(e);
-                };
-                ancestors_store.insert(
-                    class_id,
-                    // if class has direct parents, get all ancestors of its parents. Else just empty
-                    if class_ancestors.is_empty() {
-                        vec![]
-                    } else {
-                        Self::get_all_ancestors_helper(
-                            &class_ancestors[0],
-                            temp_def_list.as_slice(),
-                        )?
-                    },
-                );
-                Ok(())
-            };
-        for (class_def, ast) in self.definition_ast_list.iter().skip(self.builtin_num) {
-            if ast.is_none() {
-                continue;
-            }
-            if let Err(e) = get_all_ancestors(class_def) {
-                errors.extend(e);
-            }
-        }
-        if !errors.is_empty() {
-            return Err(errors);
-        }
-
-        // insert the ancestors to the def list
-        for (class_def, class_ast) in self.definition_ast_list.iter_mut().skip(self.builtin_num) {
-            if class_ast.is_none() {
-                continue;
-            }
-            let mut class_def = class_def.write();
-            let (class_ancestors, class_id, class_type_vars) = {
-                if let TopLevelDef::Class { ancestors, object_id, type_vars, .. } = &mut *class_def
-                {
-                    (ancestors, *object_id, type_vars)
-                } else {
-                    continue;
                 }
-            };
+                // Get class ancestors order matters here. Like python we will only consider classes to be correct if they are in same order
+                Self::analyze_ancestors(class_def, &temp_def_list);
 
-            let ans = ancestors_store.get_mut(&class_id).unwrap();
+                let mut type_var_to_concrete_def: HashMap<Type, TypeAnnotation> = HashMap::new();
-            class_ancestors.append(ans);
+                if let Err(e) = Self::analyze_single_class_methods_fields(
+                    class_def,
+                    &class_ast.as_ref().unwrap().node,
+                    &temp_def_list,
+                    unifier,
+                    primitives_store,
+                    &mut type_var_to_concrete_def,
+                    core_info,
+                ) {
+                    errors.extend(e);
+                }
 
-            // insert self type annotation to the front of the vector to maintain the order
+                // special case classes that inherit from Exception
-            class_ancestors
+                let TopLevelDef::Class { ancestors: class_ancestors, loc, .. } = &*class_def.read()
-                .insert(0, make_self_type_annotation(class_type_vars.as_slice(), class_id));
+                else {
-
-            // special case classes that inherit from Exception
-            if class_ancestors
-                .iter()
-                .any(|ann| matches!(ann, TypeAnnotation::CustomClass { id, .. } if id.0 == 7))
-            {
-                // if inherited from Exception, the body should be a pass
-                let ast::StmtKind::ClassDef { body, .. } = &class_ast.as_ref().unwrap().node else {
                     unreachable!()
                 };
-
+                if class_ancestors
-                for stmt in body {
+                    .iter()
-                    if matches!(
+                    .any(|ann| matches!(ann, TypeAnnotation::CustomClass { id, .. } if id.0 == 7))
-                        stmt.node,
+                {
-                        ast::StmtKind::FunctionDef { .. } | ast::StmtKind::AnnAssign { .. }
+                    // if inherited from Exception, the body should be a pass
-                    ) {
+                    let ast::StmtKind::ClassDef { body, .. } = &class_ast.as_ref().unwrap().node
-                        return Err(HashSet::from([
+                    else {
-                            "Classes inherited from exception should have no custom fields/methods"
+                        unreachable!()
-                                .into(),
+                    };
-                        ]));
+                    for stmt in body {
+                        if matches!(
+                            stmt.node,
+                            ast::StmtKind::FunctionDef { .. } | ast::StmtKind::AnnAssign { .. }
+                        ) {
+                            errors.extend(report_error("Classes inherited from exception should have no custom fields/methods", loc.unwrap()));
+                        }
                     }
                 }
             }
+            // println!("Adding class_def of {name} to the temp_def_list with ID {}", object_id.0);
+            temp_def_list.push(class_def.clone());
         }
 
         // deal with ancestor of Exception object
-        let TopLevelDef::Class { name, ancestors, object_id, .. } =
+        let TopLevelDef::Class { name, ancestors, object_id, .. } = &mut *def_list[7].0.write()
-            &mut *self.definition_ast_list[7].0.write()
         else {
             unreachable!()
         };
-
         assert_eq!(*name, "Exception".into());
         ancestors.push(make_self_type_annotation(&[], *object_id));
 
+        if !errors.is_empty() {
+            return Err(errors);
+        }
         Ok(())
     }
 
@@ -1199,126 +1103,81 @@ impl TopLevelComposer {
                     let mut method_var_map = VarMap::new();
 
                     let arg_types: Vec<FuncArg> = {
-                        // check method parameters cannot have same name
+                        // Function arguments must have:
+                        // 1) `self` as first argument
+                        // 2) unique names
+                        // 3) names different than keywords
+                        match args.args.first() {
+                            Some(id) if id.node.arg == "self".into() => {},
+                            _ => return report_error("class method must have a `self` parameter", b.location),
+                        }
                         let mut defined_parameter_name: HashSet<_> = HashSet::new();
-                        let zelf: StrRef = "self".into();
+                        for arg in args.args.iter().skip(1) {
-                        for x in &args.args {
+                            if !defined_parameter_name.insert(arg.node.arg) {
-                            if !defined_parameter_name.insert(x.node.arg)
+                                return report_error("class method must have a unique parameter names", b.location)
-                                || (keyword_list.contains(&x.node.arg) && x.node.arg != zelf)
+                            }
-                            {
+                            if keyword_list.contains(&arg.node.arg) {
-                                return Err(HashSet::from([
+                                return report_error("parameter names should not be the same as the keywords", b.location)
-                                    format!("top level function must have unique parameter names \
-                                    and names should not be the same as the keywords (at {})",
-                                    x.location),
-                                ]))
                             }
                         }
 
-                        if name == &"__init__".into() && !defined_parameter_name.contains(&zelf) {
+                        // `self` must not be provided type annotation or default value
-                            return Err(HashSet::from([
+                        if args.args.len() == args.defaults.len() {
-                                format!("__init__ method must have a `self` parameter (at {})", b.location),
+                            return report_error("`self` cannot have a default value", b.location)
-                            ]))
                         }
-                        if !defined_parameter_name.contains(&zelf) {
+                        if args.args[0].node.annotation.is_some() {
-                            return Err(HashSet::from([
+                            return report_error("`self` cannot have a type annotation", b.location)
-                                format!("class method must have a `self` parameter (at {})", b.location),
-                            ]))
                         }
-
                         let mut result = Vec::new();
-
+                        let no_defaults = args.args.len() - args.defaults.len() - 1;
-                        let arg_with_default: Vec<(
+                        for (idx, x) in itertools::enumerate(args.args.iter().skip(1)) {
-                            &ast::Located<ast::ArgData<()>>,
+                            let type_ann = {
-                            Option<&ast::Expr>,
+                                let Some(annotation_expr) = x.node.annotation.as_ref() else {return report_error(format!("type annotation needed for `{}`", x.node.arg).as_str(), x.location)};
-                        )> = args
+                                parse_ast_to_type_annotation_kinds(
-                            .args
+                                    class_resolver,
-                            .iter()
+                                    temp_def_list,
-                            .rev()
+                                    unifier,
-                            .zip(
+                                    primitives,
-                                args.defaults
+                                    annotation_expr,
-                                    .iter()
+                                    vec![(class_id, class_type_vars_def.clone())]
-                                    .rev()
+                                        .into_iter()
-                                    .map(|x| -> Option<&ast::Expr> { Some(x) })
+                                        .collect::<HashMap<_, _>>(),
-                                    .chain(std::iter::repeat(None)),
+                                )?
-                            )
+                            };
-                            .collect_vec();
+                            // find type vars within this method parameter type annotation
-
+                            let type_vars_within = get_type_var_contained_in_type_annotation(&type_ann);
-                        for (x, default) in arg_with_default.into_iter().rev() {
+                            // handle the class type var and the method type var
-                            let name = x.node.arg;
+                            for type_var_within in type_vars_within {
-                            if name != zelf {
+                                let TypeAnnotation::TypeVar(ty) = type_var_within else {
-                                let type_ann = {
+                                    unreachable!("must be type var annotation")
-                                    let annotation_expr = x
-                                        .node
-                                        .annotation
-                                        .as_ref()
-                                        .ok_or_else(|| HashSet::from([
-                                            format!(
-                                                "type annotation needed for `{}` at {}",
-                                                x.node.arg, x.location
-                                            ),
-                                        ]))?
-                                        .as_ref();
-                                    parse_ast_to_type_annotation_kinds(
-                                        class_resolver,
-                                        temp_def_list,
-                                        unifier,
-                                        primitives,
-                                        annotation_expr,
-                                        vec![(class_id, class_type_vars_def.clone())]
-                                            .into_iter()
-                                            .collect::<HashMap<_, _>>(),
-                                    )?
                                 };
-                                // find type vars within this method parameter type annotation
-                                let type_vars_within =
-                                    get_type_var_contained_in_type_annotation(&type_ann);
-                                // handle the class type var and the method type var
-                                for type_var_within in type_vars_within {
-                                    let TypeAnnotation::TypeVar(ty) = type_var_within else {
-                                        unreachable!("must be type var annotation")
-                                    };
 
-                                    let id = Self::get_var_id(ty, unifier)?;
+                                let id = Self::get_var_id(ty, unifier)?;
-                                    if let Some(prev_ty) = method_var_map.insert(id, ty) {
+                                if let Some(prev_ty) = method_var_map.insert(id, ty) {
-                                        // if already in the list, make sure they are the same?
+                                    // if already in the list, make sure they are the same?
-                                        assert_eq!(prev_ty, ty);
+                                    assert_eq!(prev_ty, ty);
-                                    }
                                 }
-                                // finish handling type vars
-                                let dummy_func_arg = FuncArg {
-                                    name,
-                                    ty: unifier.get_dummy_var().ty,
-                                    default_value: match default {
-                                        None => None,
-                                        Some(default) => {
-                                            if name == "self".into() {
-                                                return Err(HashSet::from([
-                                                    format!("`self` parameter cannot take default value (at {})", x.location),
-                                                ]));
-                                            }
-                                            Some({
-                                                let v = Self::parse_parameter_default_value(
-                                                    default,
-                                                    class_resolver,
-                                                )?;
-                                                Self::check_default_param_type(
-                                                    &v, &type_ann, primitives, unifier,
-                                                )
-                                                .map_err(|err| HashSet::from([
-                                                    format!("{} (at {})", err, x.location),
-                                                ]))?;
-                                                v
-                                            })
-                                        }
-                                    },
-                                    is_vararg: false,
-                                };
-                                // push the dummy type and the type annotation
-                                // into the list for later unification
-                                type_var_to_concrete_def
-                                    .insert(dummy_func_arg.ty, type_ann.clone());
-                                result.push(dummy_func_arg);
                             }
+                            // finish handling type vars
+                            let dummy_func_arg = FuncArg {
+                                name: x.node.arg,
+                                ty: unifier.get_dummy_var().ty,
+                                default_value: if idx < no_defaults { None } else {
+                                    let default_idx = idx - no_defaults;
+
+                                    Some({
+                                        let v = Self::parse_parameter_default_value(&args.defaults[default_idx], class_resolver)?;
+                                        Self::check_default_param_type(&v, &type_ann, primitives, unifier).map_err(|err| report_error::<()>(err.as_str(), x.location).unwrap_err())?;
+                                        v
+                                    })
+                                },
+                                is_vararg: false,
+                            };
+                            // push the dummy type and the type annotation
+                            // into the list for later unification
+                            type_var_to_concrete_def
+                                .insert(dummy_func_arg.ty, type_ann.clone());
+                            result.push(dummy_func_arg);
                         }
                         result
                     };
@@ -1440,23 +1299,13 @@ impl TopLevelComposer {
                                             match v {
                                                 ast::Constant::Bool(_) | ast::Constant::Str(_) | ast::Constant::Int(_) | ast::Constant::Float(_) => {}
                                                 _ => {
-                                                        return Err(HashSet::from([
+                                                        return report_error("unsupported statement in class definition body", b.location)
-                                                        format!(
-                                                            "unsupported statement in class definition body (at {})",
-                                                            b.location
-                                                        ),
-                                                    ]))
                                                 }
                                             }
                                             class_attributes_def.push((*attr, dummy_field_type, v.clone()));
                                         }
                                         _ => {
-                                            return Err(HashSet::from([
+                                            return report_error("unsupported statement in class definition body", b.location)
-                                                format!(
-                                                    "unsupported statement in class definition body (at {})",
-                                                    b.location
-                                                ),
-                                            ]))
                                         }
                                     }
                                     annotation
@@ -1482,43 +1331,22 @@ impl TopLevelComposer {
                                 };
 
                                 if !class_type_vars_def.contains(&t) {
-                                    return Err(HashSet::from([
+                                    return report_error("class fields can only use type vars over which the class is generic", b.location)
-                                        format!(
-                                            "class fields can only use type \
-                                                vars over which the class is generic (at {})",
-                                            annotation.location
-                                        ),
-                                    ]))
                                 }
                             }
                             type_var_to_concrete_def.insert(dummy_field_type, parsed_annotation);
                         } else {
-                            return Err(HashSet::from([
+                            return report_error(format!("same class fields `{}` defined twice", attr).as_str(), target.location)
-                                format!(
-                                    "same class fields `{}` defined twice (at {})",
-                                    attr, target.location
-                                ),
-                            ]))
                         }
                     } else {
-                        return Err(HashSet::from([
+                        return report_error("unsupported statement in class definition body", target.location)
-                            format!(
-                                "unsupported statement type in class definition body (at {})",
-                                target.location
-                            ),
-                        ]))
                     }
                 }
                 ast::StmtKind::Assign { .. } // we don't class attributes
                 | ast::StmtKind::Expr { value: _, .. } // typically a docstring; ignoring all expressions matches CPython behavior
                 | ast::StmtKind::Pass { .. } => {}
                 _ => {
-                    return Err(HashSet::from([
+                    return report_error("unsupported statement in class definition body", b.location)
-                        format!(
-                            "unsupported statement in class definition body (at {})",
-                            b.location
-                        ),
-                    ]))
                 }
             }
         }
@@ -1570,44 +1398,27 @@ impl TopLevelComposer {
 
         // handle methods override
         // since we need to maintain the order, create a new list
-        let mut new_child_methods: Vec<(StrRef, Type, DefinitionId)> = Vec::new();
+        let mut new_child_methods: IndexMap<StrRef, (Type, DefinitionId)> = methods.iter().map(|m| (m.0.clone(), (m.1.clone(), m.2.clone()))).collect();
-        let mut is_override: HashSet<StrRef> = HashSet::new();
+        // let mut new_child_methods: Vec<(StrRef, Type, DefinitionId)> = methods.clone();
-        for (anc_method_name, anc_method_ty, anc_method_def_id) in methods {
+        for (class_method_name, class_method_ty, class_method_defid) in &*class_methods_def {
-            // find if there is a method with same name in the child class
+            if let Some((ty, _ ) ) = new_child_methods.insert(*class_method_name, (*class_method_ty, *class_method_defid)) {
-            let mut to_be_added = (*anc_method_name, *anc_method_ty, *anc_method_def_id);
+                let ok = class_method_name == &"__init__".into()
-            for (class_method_name, class_method_ty, class_method_defid) in &*class_methods_def {
+                || Self::check_overload_function_type(
-                if class_method_name == anc_method_name {
+                    *class_method_ty,
-                    // ignore and handle self
+                    ty,
-                    // if is __init__ method, no need to check return type
+                    unifier,
-                    let ok = class_method_name == &"__init__".into()
+                    type_var_to_concrete_def,
-                        || Self::check_overload_function_type(
+                );
-                            *class_method_ty,
+                if !ok {
-                            *anc_method_ty,
+                    return Err(HashSet::from([format!(
-                            unifier,
+                        "method {class_method_name} has same name as ancestors' method, but incompatible type"),
-                            type_var_to_concrete_def,
+                    ]));
-                        );
-                    if !ok {
-                        return Err(HashSet::from([format!(
-                            "method {class_method_name} has same name as ancestors' method, but incompatible type"),
-                        ]));
-                    }
-                    // mark it as added
-                    is_override.insert(*class_method_name);
-                    to_be_added = (*class_method_name, *class_method_ty, *class_method_defid);
-                    break;
                 }
             }
-            new_child_methods.push(to_be_added);
         }
-        // add those that are not overriding method to the new_child_methods
-        for (class_method_name, class_method_ty, class_method_defid) in &*class_methods_def {
-            if !is_override.contains(class_method_name) {
-                new_child_methods.push((*class_method_name, *class_method_ty, *class_method_defid));
-            }
-        }
-        // use the new_child_methods to replace all the elements in `class_methods_def`
         class_methods_def.clear();
-        class_methods_def.extend(new_child_methods);
+        class_methods_def.extend(new_child_methods.iter().map(|f| (f.0.clone(), f.1.0, f.1.1)).collect_vec());
+        let is_override: HashSet<StrRef> = HashSet::new();
 
         // handle class fields
         let mut new_child_fields: Vec<(StrRef, Type, bool)> = Vec::new();

nac3core/src/toplevel/type_annotation.rs

@@ -1,6 +1,7 @@
 use super::*;
 use crate::symbol_resolver::SymbolValue;
 use crate::toplevel::helper::{PrimDef, PrimDefDetails};
+use crate::typecheck::type_inferencer::report_error;
 use crate::typecheck::typedef::VarMap;
 use nac3parser::ast::Constant;
 use strum::IntoEnumIterator;
@@ -97,7 +98,13 @@ pub fn parse_ast_to_type_annotation_kinds<T, S: std::hash::BuildHasher + Clone>(
             Ok(TypeAnnotation::CustomClass { id: PrimDef::Exception.id(), params: Vec::default() })
         } else if let Ok(obj_id) = resolver.get_identifier_def(*id) {
             let type_vars = {
-                let def_read = top_level_defs[obj_id.0].try_read();
+                let Some(top_level_def) = top_level_defs.get(obj_id.0) else {
+                    return report_error(
+                        format!("Name Error undefined name {id}").as_str(),
+                        expr.location,
+                    );
+                };
+                let def_read = top_level_def.try_read();
                 if let Some(def_read) = def_read {
                     if let TopLevelDef::Class { type_vars, .. } = &*def_read {
                         type_vars.clone()

nac3core/src/typecheck/magic_methods.rs

@@ -520,6 +520,23 @@ pub fn typeof_binop(
         }
 
         Operator::MatMult => {
+            // NOTE: NumPy matmul's LHS and RHS must both be ndarrays. Scalars are not allowed.
+            match (&*unifier.get_ty(lhs), &*unifier.get_ty(rhs)) {
+                (
+                    TypeEnum::TObj { obj_id: lhs_obj_id, .. },
+                    TypeEnum::TObj { obj_id: rhs_obj_id, .. },
+                ) if *lhs_obj_id == primitives.ndarray.obj_id(unifier).unwrap()
+                    && *rhs_obj_id == primitives.ndarray.obj_id(unifier).unwrap() =>
+                {
+                    // LHS and RHS have valid types
+                }
+                _ => {
+                    let lhs_str = unifier.stringify(lhs);
+                    let rhs_str = unifier.stringify(rhs);
+                    return Err(format!("ndarray.__matmul__ only accepts ndarray operands, but left operand has type {lhs_str}, and right operand has type {rhs_str}"));
+                }
+            }
+
             let (_, lhs_ndims) = unpack_ndarray_var_tys(unifier, lhs);
             let lhs_ndims = match &*unifier.get_ty_immutable(lhs_ndims) {
                 TypeEnum::TLiteral { values, .. } => {

nac3core/src/typecheck/type_inferencer/mod.rs

@@ -114,7 +114,7 @@ impl Fold<()> for NaiveFolder {
     }
 }
 
-fn report_error<T>(msg: &str, location: Location) -> Result<T, InferenceError> {
+pub fn report_error<T>(msg: &str, location: Location) -> Result<T, InferenceError> {
     Err(HashSet::from([format!("{msg} at {location}")]))
 }
 

nac3standalone/demo/interpreted.log

@@ -0,0 +1,26 @@
+1
+2
+3
+4
+5
+1
+2
+3
+4
+5
+1
+2
+3
+4
+5
+1
+0
+2
+1
+2
+False
+4
+5
+6
+7
+8

nac3standalone/src/main.rs

@@ -314,6 +314,15 @@ fn main() {
     let resolver =
         Arc::new(Resolver(internal_resolver.clone())) as Arc<dyn SymbolResolver + Send + Sync>;
 
+    let context = inkwell::context::Context::create();
+
+    // Process IRRT
+    let irrt = load_irrt(&context, resolver.as_ref());
+    if emit_llvm {
+        irrt.write_bitcode_to_path(Path::new("irrt.bc"));
+    }
+
+    // Process the Python script
     let parser_result = parser::parse_program(&program, file_name.into()).unwrap();
 
     for stmt in parser_result {
@@ -418,8 +427,8 @@ fn main() {
     registry.add_task(task);
     registry.wait_tasks_complete(handles);
 
+    // Link all modules together into `main`
     let buffers = membuffers.lock();
-    let context = inkwell::context::Context::create();
     let main = context
         .create_module_from_ir(MemoryBuffer::create_from_memory_range(&buffers[0], "main"))
         .unwrap();
@@ -439,12 +448,9 @@ fn main() {
         main.link_in_module(other).unwrap();
     }
 
-    let irrt = load_irrt(&context);
-    if emit_llvm {
-        irrt.write_bitcode_to_path(Path::new("irrt.bc"));
-    }
     main.link_in_module(irrt).unwrap();
 
+    // Private all functions except "run"
     let mut function_iter = main.get_first_function();
     while let Some(func) = function_iter {
         if func.count_basic_blocks() > 0 && func.get_name().to_str().unwrap() != "run" {
@@ -453,6 +459,7 @@ fn main() {
         function_iter = func.get_next_function();
     }
 
+    // Optimize `main`
     let target_machine = llvm_options
         .target
         .create_target_machine(llvm_options.opt_level)
@@ -466,6 +473,7 @@ fn main() {
         panic!("Failed to run optimization for module `main`: {}", err.to_string());
     }
 
+    // Write output
     target_machine
         .write_to_file(&main, FileType::Object, Path::new("module.o"))
         .expect("couldn't write module to file");