@codemirror/language

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This package implements the language support infrastructure for the CodeMirror code editor.

The project page has more information, a number of examples and the documentation.

This code is released under an MIT license.

We aim to be an inclusive, welcoming community. To make that explicit, we have a code of conduct that applies to communication around the project.

Usage

Setting up a language from a Lezer parser looks like this:

import {parser} from "@lezer/json"
import {LRLanguage, continuedIndent, indentNodeProp,
        foldNodeProp, foldInside} from "@codemirror/language"

export const jsonLanguage = LRLanguage.define({
  name: "json",
  parser: parser.configure({
    props: [
      indentNodeProp.add({
        Object: continuedIndent({except: /^\s*\}/}),
        Array: continuedIndent({except: /^\s*\]/})
      }),
      foldNodeProp.add({
        "Object Array": foldInside
      })
    ]
  }),
  languageData: {
    closeBrackets: {brackets: ["[", "{", '"']},
    indentOnInput: /^\s*[\}\]]$/
  }
})

Often, you'll also use this package just to access some specific language-related features, such as accessing the editor's syntax tree...

import {syntaxTree} from "@codemirror/language"

const tree = syntaxTree(view)

... or computing the appriate indentation at a given point.

import {getIndentation} from "@codemirror/language"

console.log(getIndentation(view.state, view.state.selection.main.head))