tbmreza / tree-sitter-utlc

Tree-sitter grammar for utlc: a subset of Scheme that's restricted, but enough to facilitate programming in the untyped lambda-calculus.

Tree-sitter grammar for utlc: a subset of Scheme that's restricted, but enough to facilitate programming in the untyped lambda-calculus.

Status

Work in progress. Repository used tree-sitter-rust as scaffold, so maybe look at that instead.

Developing the grammar

Extending this simple language to a RnRS Scheme subset is something that I want to do sometime (or maybe you do today). I think it's worthwhile to write a proper documentation here.

Use cargo installed tree-sitter binary!

Following steps in tree-sitter docs exactly did confuse me. Instead of using npm as advised there, I suggest using the binary installed at ~/.cargo/bin/tree-sitter. My experience using npm:

• Dependencies got displaced from package.json after invoking tree-sitter generate.
• tree-sitter generate can only run once; you have to npm init all over again if you decide that you have changes to grammar.js. This is a bug because docs says otherwise.

Tests

tree-sitter test -f <testcase name, not filename>  # providing it with a filter that doesn't catch anything might surprise you
tree-sitter test  # reads test/corpus/*

Simple usage

# edit rules at grammar.js
tree-sitter generate  # expect modifications at src/grammar.json
tree-sitter parse example-file