tree-sitter-gmat

A tree-sitter grammar for GMAT (NASA's General Mission Analysis Tool) mission scripts — .script files and GmatFunctions (.gmf), one grammar for both.

It is a deliberately permissive superset of GMAT's scripting language: Create <Type> <name> accepts any resource type, and unknown command keywords parse as generic command nodes, so a new resource or command never needs a grammar change. Any input re-emits byte-for-byte, comments and layout included. The grammar parses all 162 .script and 9 .gmf files shipped with NASA GMAT R2026a with zero errors.

What's in the package

• the generated parser (src/parser.c and the external scanner) plus grammar.js
• queries/highlights.scm for editor syntax highlighting
• the tree-sitter config — scope source.gmat, file types .script and .gmf

Usage

This package provides the grammar and highlight queries for tree-sitter-based editors and tooling. Point a tree-sitter-aware editor (Neovim / nvim-treesitter, Helix, Zed, …) or the tree-sitter CLI at it for parsing and .script / .gmf syntax highlighting. To embed the parser in another language, compile the bundled src/parser.c against that language's tree-sitter bindings.

Parsing from Python

For a batteries-included parser built on this grammar — parse(), structured error reporting, byte-exact re-emission, and the gmat-script parse CLI — use gmat-script:

pip install gmat-script

Links

• Documentation: https://astro-tools.github.io/gmat-script/
• Source: https://github.com/astro-tools/gmat-script

License

MIT — part of the astro-tools organization.