corelang/README.md

The Core Language

Core is an experimental systems programming language and compiler I built as one of my first "full" language projects.

It is intentionally kept here as a learning artifact: useful to read, fun to tinker with, and definitely not production-ready.

What this project is

• A compiler written in C++
• A language with .core source files
• A C code generator backend (Core -> C)
• A small standard-module set in modules/
• A collection of examples in examples/

The compiler aims for simple syntax, explicit behavior, and debuggable output.

Current status

• Archived hobby project / historical snapshot
• Works in many cases, but has known bugs and rough edges
• Best viewed as a language implementation study, not a stable toolchain
• I have made modifications over time and have not recently re-verified a clean build, so the project may not build out of the box

If you are new to compilers, this repo can still be valuable as a real-world "first serious compiler" codebase.

Language highlights

• Static typing with strict checks
• Untyped compile-time constants (with big-int support in constant evaluation)
• Order-independent declarations
• Modules via #import
• Conditional loading (for example OS-specific modules)
• Slices, arrays, structs, unions, enums
• Multiple return values
• Operator overloading
• Runtime type information (Type, GetTypeInfo, Any)

Tiny syntax taste

#import "Multimedia.core"

main :: (): int
  StartMultimedia(title = "Hello people!")
  for UpdateMultimedia()
    if Mu.key[Key.Escape].down
      Mu.quit = true

    for y := 0, y < Mu.window.y, y += 1
      for x := 0, x < Mu.window.x, x += 1
        Mu.screen[x + y * Mu.window.x] = 0xFFFFFF00

  return 0

For more examples, see:

• examples/language_basics.core
• examples/arrays_and_slices.core
• examples/operator_overloading.core
• examples/runtime_type_information.core

Compiler pipeline

At a high level:

1. Lex + parse .core source into AST
2. Resolve symbols and types
3. Generate C code (generated_main.c)
4. Optionally compile generated C with clang

One design goal was debugger friendliness, so generated C includes line synchronization for stepping through source.

Building the compiler

Windows

build.bat

This builds the compiler executable in build/.

Linux

build_unix.sh exists, but the repo layout changed over time. If it fails, build manually:

clang src/language/core_main.cpp -O0 -Wall -Wno-unused-function -fno-exceptions -fdiagnostics-absolute-paths -g -o core.out

Running it

Compile one source file to C:

./core.out examples/language_basics.core

or on Windows:

build\main.exe examples\language_basics.core

This produces generated_main.c.

Then compile the generated C yourself (example):

clang generated_main.c -Wall -Wno-unused-function -Wno-parentheses-equality -g -o a.out

There is also a test mode:

./core.out -testing

which iterates through examples/ (and tests/ if present), compiles, and runs them.

Repository map

• src/language/ - compiler front/mid/back-end implementation
• src/base/ - memory, strings, containers, utilities
• src/os/ - OS abstraction layer (Windows/Linux)
• modules/ - language modules and platform bindings
• examples/ - sample Core programs
• tools/meta.py - meta tables used to generate token/keyword boilerplate

Known rough edges

• Project paths changed over time; some scripts may need adjustment
• Windows support is more mature than Linux in some areas
• No polished package manager or full modern tooling around the language
• Feature set is incomplete (for example, no finished generics system)

Why keep this repo public?

Because complete-but-imperfect projects are useful. This codebase captures:

• early language design decisions
• practical compiler architecture tradeoffs
• how a transpile-to-C strategy can speed up experimentation

If you are building your own language, you may find useful ideas here (and just as many cautionary tales).

Learning resources that inspired this project

• https://bitwise.handmade.network/
• https://hero.handmade.network/episode/code/day206/
• https://www.youtube.com/watch?v=TH9VCN6UkyQ&list=PLmV5I2fxaiCKfxMBrNsU1kgKJXD3PkyxO
• A Retargetable C Compiler: Design and Implementation (Fraser/Hanson)
• https://github.com/c3lang/c3c
• https://go.dev/blog/constants
• https://github.com/gingerbill/odin