Getting started

Requirements: CMake 3.28+, a C++23 compiler and Python 3. CMake finds or downloads the LLVM 23.1 SDK and other dependencies; on Windows use a Visual Studio x64 developer shell with Ninja and LLVM/Clang installed. Details: building.

Build:

cmake --preset debug          # Windows: cmake --preset windows
cmake --build --preset debug  # Windows: cmake --build --preset windows-release

clau lands in build/debug/bin (Windows: build/windows/bin/Release).

Write a program; the entry is the module exporting main/1, which receives the command-line arguments as strings:

-module(hello).
-export([main/1]).

main(Args) -> io:format("Hello, ~p~n", [Args]).

Compile and run it:

clau -O2 -o hello hello.erl
./hello world

For more than a few files, describe targets in a TOML project:

clau --new-project myapp       # writes an annotated myapp.toml
clau --project myapp.toml

clau --help lists every option.