tree-sitter-rdx

Tree-sitter grammar for RDX (Reactive Document eXpressions).

Provides syntax highlighting, code folding, and structural analysis for any editor that supports tree-sitter (Neovim, Helix, Zed, Emacs, etc.).

Parsed constructs

• Frontmatter (--- delimited YAML metadata)
• Components — open/close tags, self-closing, nested
• Attributes — string, primitive, JSON, variable, boolean shorthand (including hyphenated names like data-id)
• Variable interpolation — {$path.to.value}
• Escape sequences — \{$, \{{, \}}, \{, \\
• Fenced code blocks with language tags (external scanner)
• Display math $$...$$ (external scanner) and inline math $...$
• Plain text and inline code

Markdown formatting (bold, italic, headings, lists) is intentionally treated as plain text — RDX components and variables are the tree-sitter grammar's concern, not Markdown structure.

Usage

Neovim

Add to your tree-sitter config:

require("nvim-treesitter.configs").setup({
  ensure_installed = { "rdx" },
})

Helix

Add to languages.toml:

[[language]]
name = "rdx"
scope = "source.rdx"
file-types = ["rdx"]
roots = []

[language.auto-pairs]

[[grammar]]
name = "rdx"
source = { git = "https://github.com/rdx-lang/tree-sitter-rdx", rev = "main" }

Development

bun install
bunx tree-sitter generate
bunx tree-sitter test

Parse a file

bunx tree-sitter parse test/example.rdx

Project structure

grammar.js          — Grammar definition
src/scanner.c       — External scanner (code fences, math fences, frontmatter)
queries/
  highlights.scm    — Syntax highlighting queries
  injections.scm    — Language injection queries
test/
  corpus/           — Tree-sitter corpus tests
  example.rdx       — Full kitchen-sink example

License

MIT