Update grammar to cover array spreads, variant type spreads and newer operators.

[mvaled]

Disclosure: This PR was generated with AI assistance and reviewed by the author. The author's goal is to improve the Emacs rescript-ts-mode (jjlee/rescript-mode#19).

Summary

This PR updates the Tree-sitter grammar to better match recent ReScript language features across three areas:

1. ReScript 12 operator support
2. Variant spread syntax
3. Array spread expressions

What changed

1. ReScript 12 operator support

Added grammar support for the newer operator syntax introduced in ReScript 12, including:

• modulo: %

• bitwise operators:

  • &&&
  • |||
  • ^^^
  • ~~~

• shift operators:

  • <<
  • >>
  • >>>

2. Variant spread syntax

Added support for:

• variant type spreads, e.g.

  type base = Start | Stop | Pause
  type extended = | ...base | Resume

• variant pattern spreads, e.g.

  let handle = (event: extended) =>
      switch event {
      | ...base as core => Console.log2("base", core)
      | Resume => Console.log("resuming")
      }

3. Array spread expressions

Added support for spread elements inside array literals, including multiple spreads, e.g.

let animals = ["🐶", "🐱", "🐷"]
let moreAnimals = [...animals, "🐔", "🐴", "🐮", ...otherAnimals]

This brings the grammar in line with array spread syntax available since ReScript v11.

[nojaf]

Hello @mvaled, thanks for this PR!
Could you check the failing tests in CI?
I've asked @aspeddro for a review as he knows most about this stuff.

[mvaled]

Hello @mvaled, thanks for this PR! Could you check the failing tests in CI? I've asked @aspeddro for a review as he knows most about this stuff.

Hi @nojaf, @aspeddro,

Fixed. The problem was I used a different tree-sitter version that the one in the CI.

I took the liberty to update the .github/workflows/ci.yml to pin the tree-sitter version, and the peerDependency in package.json.

[Copilot]

Pull request overview

Updates the Tree-sitter ReScript grammar and associated artifacts to support newer ReScript language constructs (ReScript 12 operators, variant spreads, and array spreads), improving parsing and editor integrations (e.g., rescript-ts-mode).

Changes:

• Extend the grammar to parse variant type spreads, variant pattern spreads, and array spread elements.
• Add parsing support for ReScript 12 operators (%, bitwise ops, and shift ops) with precedence updates.
• Regenerate/update Tree-sitter artifacts (node types, generated grammar JSON) and adjust CI/runtime tooling versions.

Reviewed changes

Copilot reviewed 8 out of 10 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
grammar.js	Implements grammar rule updates for operators, variant spreads, array spreads, and extensible variant types.
src/grammar.json	Regenerated grammar JSON reflecting new/updated grammar rules and precedences.
src/node-types.json	Regenerated node-types including new nodes/tokens (e.g., extensible_type, spread/pattern nodes, operator tokens).
test/corpus/type_declarations.txt	Adds/updates corpus coverage for extensible variants and variant type spreads.
test/corpus/expressions.txt	Adds corpus coverage for variant pattern spreads, modulo, bitwise operators, shift operators, and array spreads.
queries/highlights.scm	Adds highlighting for newly supported operators.
package.json	Updates tree-sitter peer dependency version requirement.
package-lock.json	Lockfile update to match package.json peer dependency change.
.github/workflows/ci.yml	Ensures CI runs when Node/tooling files change and pins the Tree-sitter CLI ref used in CI.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.