@enspirit/codemirror-lang-elo

Elo language support for CodeMirror 6.

Provides syntax highlighting, bracket matching, code folding, indentation, comment toggling, and autocompletion for the Elo expression language via a proper Lezer grammar (incremental parsing, full syntax tree).

Installation

npm install @enspirit/codemirror-lang-elo

Usage

import { EditorView, basicSetup } from "codemirror";
import { elo } from "@enspirit/codemirror-lang-elo";

new EditorView({
  extensions: [basicSetup, elo()],
  parent: document.querySelector("#editor"),
});

What you get

• Syntax highlighting for all Elo constructs: keywords, strings, numbers, dates, durations, temporal keywords, types, operators, comments.
• Bracket matching for (), [], {}.
• Code folding for objects, arrays, lambdas, and type schemas.
• Indentation support inside delimited blocks.
• Comment toggling with #.
• Autocompletion for stdlib functions, keywords, temporal keywords, and built-in type names.

Advanced: accessing the language object

If you need the LRLanguage instance (e.g. for custom extensions):

import { eloLanguage } from "@enspirit/codemirror-lang-elo";

// eloLanguage is an LRLanguage — use it to build custom LanguageSupport,
// access the parser, etc.
const parser = eloLanguage.parser;

Theming

This package provides language support only, not a theme. Syntax nodes are mapped to standard @lezer/highlight tags, so any CodeMirror theme will work. The tags used are:

| Elo construct | Highlight tag | |---|---| | let, in, fn | definitionKeyword | | if, then, else, guard, check | controlKeyword | | and, or, not | operatorKeyword | | true, false | bool | | null | null | | Numbers | number | | Strings | string | | Date / DateTime literals | special(literal) | | Duration literals | special(number) | | Temporal keywords (NOW, TODAY, ...) | standard(variableName) | | Type names (Int, String, ...) | typeName | | Function calls | function(variableName) | | Property names | propertyName | | Comments | lineComment | | Operators | compareOperator, arithmeticOperator, logicOperator, operator |

Development

Building

npm install
npm run prepare   # compiles the Lezer grammar and bundles with Rollup

Testing

npm test          # runs Lezer grammar tests (test/cases.txt)

Grammar test format

Tests live in test/cases.txt using the Lezer test format:

# Test name

source code here

==>

Expected(TreeStructure)

Publishing

1. Make sure all tests pass:

   npm test

2. Bump the version in package.json.

3. Build the package:

   npm run prepare

4. Publish to npm:

   npm publish --access public

   The --access public flag is required for scoped packages on the first publish.

License

MIT