Sure, here's a simple README.md that explains the usage and features of your MyLang compiler CLI:

MyLang Compiler is a simple compiler for MyLang, a toy programming language created for studying lexers, parsers, and compilers. MyLang is designed with limited features, including basic data types, recursive functions, and closures, while excluding loops and other complex constructs.

The compiler translates MyLang source code into LLVM Intermediate Representation (IR), enabling further compilation and execution using LLVM toolchains.

• Supports two data types: integer and boolean (along with a null type for void functions).
• Enables the creation of recursive functions, providing a way to loop.
• Supports closures for capturing and utilizing external variables.
• Compiles MyLang source code into LLVM IR.

To compile a MyLang program, use the provided CLI tool.

1. Make sure you have Python 3.x installed.

2. Install the required packages using pip:

   pip install llvmlite

3. Run the MyLang compiler CLI:

   python mylang_compiler_cli.py input_file.my -o output.ll

   Replace input_file.my with the path to your MyLang source code file and output.ll with the desired LLVM IR output file.

Consider the following example MyLang code saved in example.mylang:

function add(a: int, b: int) -> int {
    return a + b;
}

Compile the MyLang code to LLVM IR using the MyLang Compiler:

$ python -m mylang example.mylang -o example.ll

The resulting LLVM IR will be saved in example.ll. Compile the LLVM IR to an executable using llc and clang:

$ llc example.ll
$ clang example.s -o example

If have problems with target check the target triple. I hardcoded it, but you can change it on target triple llvm-ir statement.

To get your current target triple run:

clang -print-effective-triple