tree-sitter-moocode

Tree-sitter grammar for LambdaMOO/ToastStunt MOO code.

This package is intended to be the durable parser layer behind editor support: Monaco highlighting and diagnostics can use the lightweight language service, while Tree-sitter gives us structural parsing, queries, folding, locals, and a future path to richer browser or LSP integration.

Source Grammar

The grammar is based on C:\Users\Q\src\toaststunt\src\parser.y plus the EBNF seed used for the Monaco workstream. ToastStunt confirms:

• statement* programs.
• Block statements for if, for, while, fork, try/except, and try/finally.
• Semicolon-terminated expression, return, break, and continue statements.
• .. range syntax through parser token tTO.
• MOO property, waif property, verb call, index, range, catch, map, list, splice, and scattering forms.

Commands

npm install
npm run generate
npm run build:wasm
npm test

Browser Parser

The package includes tree-sitter-moocode.wasm for web-tree-sitter consumers:

import { Language, Parser } from "web-tree-sitter";
import mooWasmUrl from "tree-sitter-moocode/tree-sitter-moocode.wasm?url";

await Parser.init();
const language = await Language.load(mooWasmUrl);
const parser = new Parser();
parser.setLanguage(language);
const tree = parser.parse(source);

Current Scope

The first corpus covers the editor-critical parse surface:

• single statements and control statements
• conditional and loop blocks
• try/except and try/finally blocks
• assignment, ternary, catch, splice, maps, lists, ranges, verb calls, and property chains
• highlight, fold, and local-definition queries

The grammar is intentionally permissive where ToastStunt performs semantic checks after parsing, such as validating legal assignment targets or legal $ and ^ contexts.