lydian-lang

An attempt to implement the lydian-lang language in C++ using LLVM.

Building

This project uses CMake. To build, first make sure that cmake and llvm are installed:

• Install cmake
• Install llvm

Then run scripts/initial-build.sh.

Alternatively, you can follow the steps below:

1. Make the build folder if it does not exist, and enter it (this folder is ignored by git):

   mkdir build; cd build

   NOTE: All steps below must be run in the build folder.

2. Run cmake:

   cmake ..

3. Run make:

   make

4. You can now run the built executables lydian-lang, repl, and tests:

   bin/lydian-lang
   bin/repl
   bin/tests
   
   # With debug output
   DEBUG=true bin/lydian-lang
   DEBUG=true bin/tests

Because the language is a work in progress, the REPL doesn't actually "evaluate" expressions, but it does produce an AST:

Welcome to LydianLang


𝐋1> fn multiply(a b) { a * b }
fn multiply(a b) { a * b }
JSON Output from AST:
{
  "children": [
    {
      "arguments": [
        {
          "nodeType": "nt_identifier",
          "value": "a"
        },
        {
          "nodeType": "nt_identifier",
          "value": "b"
        }
      ],
      "children": [
        {
          "left": {
            "nodeType": "nt_identifier",
            "value": "a"
          },
          "nodeType": "nt_binaryExpression",
          "operator": "*",
          "right": {
            "nodeType": "nt_identifier",
            "value": "b"
          }
        }
      ],
      "nodeType": "nt_functionDeclaration"
    }
  ],
  "nodeType": "nt_root"
}

𝐋2>

Testing

Follow the same steps as above, but instead of running the lydian-lang executable, run the tests executable.

Note about compiler settings

CMake should enable this project to be built on various platforms, but I've only built it on my MacBook using a generic apple-clang Conan profile:

# ~/.conan/profiles/default

[settings]
os=Macos
os_build=Macos
arch=x86_64
arch_build=x86_64
compiler=apple-clang
compiler.version=14
compiler.libcxx=libc++
build_type=Release
[options]
[build_requires]
[env]

Debugging and building in VSCode

To debug in VSCode, follow the build steps and install all the recommended Workspace extensions. The CMake Tools extensions allow you to use CMake's build tasks from VSCode (if you're into that), and the CodeLLDB extension is used to Then you should be able to use VSCode's debug tools "automagically".