GrADS syntax for Sublime Text

Syntax highlighting and comment toggling for the GrADS scripting language (.gs / .gsf).

Unlike a docs-driven grammar, the rules here are derived directly from the GrADS C sources (gscrpt.c, gauser.c, gafunc.c, gaexpr.c, gxchpl.c), which are the ground truth for what the interpreter actually accepts — the HTML documentation is incomplete or inaccurate in several places.

Features

• Comments — * or # at the start of a record (column 0 or right after a ;), matching the parser exactly.
• Strings — single-line only; an unterminated quote is flagged as an error (GrADS reports Non-terminated constant).
• Script language — case-insensitive keywords (if/while/say/…), function/return, the 37 script intrinsics (subwrd, math_*, …).
• Compound (array) variables — _trin.n.1, with the accessor dots and index segments highlighted.
• Command strings — case-insensitive command verbs, sub-options, and the 62 built-in grid functions (ave, maskout, EXP, …).
• Implied define — name = expr shorthand (any case).
• Expressions — arithmetic / comparison / logical operators, parentheses and commas inside display / define / implied-define, persisting across concatenated string segments.
• Backtick formatting codes — fonts, super/subscript, and the `3. degree symbol.
• Shell escapes — '!cmd …' is marked as a shell command (uniform scope, persisting across concatenation).
• Comment toggling — Ctrl+/ (Cmd+/).

Installation

Package Control (recommended)

1. Install Package Control.
2. Open the Command Palette (Ctrl+Shift+P / Cmd+Shift+P) and run Package Control: Install Package.
3. Search for GrADS and install it.

Manual

Clone or download this repository into your Sublime Text packages folder (Preferences → Browse Packages…), as a folder named GrADS:

git clone https://github.com/fox91/GrADS-Sublime-syntax.git GrADS

Then open a .gs / .gsf file (or pick View → Syntax → GrADS Script) to activate it.

Developing

The grammar lives in GrADS.sublime-syntax; scope assignments are covered by syntax tests in tests/syntax_test_grads.gs.

To run the tests, place the repository in your Sublime Text packages folder as a folder named GrADS (so the test header's Packages/GrADS/… path resolves), open tests/syntax_test_grads.gs, and run Tools → Build (Ctrl+B / Cmd+B). Results appear in the output panel; press F4 to jump to a failure.

The same tests run on every push and pull request via GitHub Actions (.github/workflows/syntax.yml, using syntax-test-action).

License

MIT © Andrea Falco