JavaScript custom languages

The JavaScript-only API for combining a custom parser with caller-supplied queries was removed. If your integration used it, a language definition cannot be carried over unchanged.

Use a published language package

Import a language from @lumis-sh/lumis/langs/*. The language handle identifies a package that supplies the parser metadata and matching queries together:

import { createHighlighter } from '@lumis-sh/lumis';
import json from '@lumis-sh/lumis/langs/json';

const highlighter = await createHighlighter({ languages: [json] });

Use the language catalog to find a supported language.

Keep parser bytes local with withWasm

withWasm() lets you supply the bytes for a published language package. It does not accept replacement queries or turn an arbitrary grammar into a Lumis language:

import { createHighlighter, withWasm } from '@lumis-sh/lumis';
import json from '@lumis-sh/lumis/langs/json';
import jsonParser from '@lumis-sh/wasm-json';

const highlighter = await createHighlighter({
  languages: [withWasm(json, jsonParser)],
});

The bytes must match the size and SHA-256 in the language package. See WASM and CDN for resolution and verification rules.

Unpublished grammars

There is no supported replacement for supplying a grammar and queries that Lumis does not publish. If your application needs that capability, changing the byte resolver is not enough to upgrade it. A cross-runtime API with a package-shaped input is planned, but is not available.