Getting started¶

This page helps you orient in the Li repository. Phase 0 bootstrap is live — build with CMake + LLVM 18 below.

What you are looking at¶

Li is a compiled language for scientific computing where only provable programs build. Mandatory contracts + Lean 4; trusted IO only in docs/semantics/trusted.lean.

• Syntax: Nim-like (proc, indentation, type / object / enum)
• Types: Static, aligned with Python 3.14 typing
• Backend: LLVM 18 only
• Compiler (v0): C++17 — self-host in Li comes later (Phase 6)

Prerequisites (for when bootstrap exists)¶

You will need:

• LLVM 18 (llvm-config on PATH)
• CMake 3.20+ and Ninja
• A C++17 compiler (Clang recommended)
• Python 3.10+ (benchmark harness only)

On macOS, LLVM 18 is typically installed with Homebrew:

brew install llvm@18 cmake ninja
export LLVM_DIR="$(brew --prefix llvm@18)/lib/cmake/llvm"
export CC=clang CXX=clang++   # Xcode libc++; do not use brew's clang++ for lic

Repository layout¶

li/
  compiler/       # C++ lic (lexer → parser → types → mir → codegen)
  runtime/        # li_rt.c — panic, bounds traps
  std/            # Standard library (.li) — grows after Phase 4
  examples/       # tetris/, hello/
  benchmarks/     # physics + ML + cross-lang harness (Phase 5b)
  li-tests/      # all tests — see li-tests/README.md
  docs/           # you are here

How work is sequenced¶

Do not jump ahead of the master plan:

First commands¶

export LLVM_DIR="$(brew --prefix llvm@18)/lib/cmake/llvm"
./scripts/build.sh
./build/compiler/lic/lic smoke-llvm

After Phase 5:

./build/compiler/lic/lic build examples/tetris/main.li -o tetris --release
./tetris

Where to ask questions in the docs¶

Contributing documentation¶

See Documentation style before adding or rewriting docs.

Preview the site locally:

./scripts/build-docs.sh --strict
python3 -m http.server -d site 8000

Published at cap-jmk-real.github.io/li-language on merge to main.