cwg 0.2.0

CWG — a Git-based programming language interpreter

Coding With Git

Language Reference · Installation · Contributing · License

Work in progress. This project is in early draft stage. Syntax and semantics are subject to change.

CWG is a programming language where the source code is the git history. Commit messages are statements, branches are control flow blocks, and merges close those blocks. The interpreter walks the commit DAG and executes it as a program.

The goal is to use git as a genuine programming medium. Readable syntax, real execution, built entirely on top of version control primitives.

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Concept

Git construct	Language construct
git commit -m "..."	Statement / instruction
Branch	Conditional block or loop
Merge	Close a block, return to parent scope
Tag	Function definition
cherry-pick	Function call
revert	Exception handler / undo
git stash	Push to memory stack
git stash pop	Pop from memory stack

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Installation

CWG is published on PyPI. You need Python 3.10+ and Git installed, then:

pip install cwg

This installs the cwg command on your PATH and pulls in the runtime dependency (GitPython). No need to clone the repository to use the language.

Want to work on CWG itself? See CONTRIBUTING.md for the from-source / editable-install workflow.

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Quick Start

Write your first program — a git history that prints hello world:

mkdir hello && cd hello
git init
git commit --allow-empty -m "message = 'hello world'"
git commit --allow-empty -m "print(message)"
cwg run .
# output: hello world

cwg run accepts a .cwg script, a local git repo path, or a remote URL (https://…, git@…, ssh://…).

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Language Reference

The full syntax and semantics — control flow, scoping, the execution model, functions, exception handling, and more — live in the Language Reference.

A taste of what CWG looks like — a countdown loop, where a branch is the loop body:

git commit -m "i = 10"
git branch while/countdown
  git commit -m "while i > 0:"
  git commit -m "    print(i)"
  git commit -m "    i = i - 1"
git checkout main
git merge while/countdown
git commit -m "print('blastoff')"
# output: 10 9 8 7 6 5 4 3 2 1 blastoff

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Status

This project is a work in progress. See CONTRIBUTING.md for how to get involved.