import type { CodeTokenKind } from '../types.js';
/** One run of a listing's line as a highlighter gives it: its text, the
 *  kind of token it is (unset: plain) or a colour of its own (a CSS hex,
 *  which wins over the kind's). */
export interface CodeToken {
    text: string;
    token?: CodeTokenKind;
    color?: string;
}
/** A highlighter: the listing's lines, each as runs whose texts join into
 *  the line (tabs and spaces included). `lang` is the fence's language,
 *  lower-cased. Return undefined to leave the listing to the next
 *  highlighter (or the built-in one). */
export type CodeHighlighter = (code: string, lang: string) => CodeToken[][] | undefined;
/**
 * Register a highlighter for listings of `lang` (lower-case, as fences
 * name it: `'js'`, `'python'`), or `'*'` for every language. A highlighter
 * for a language takes precedence over `'*'`, which takes precedence over
 * the built-in tokenizer; `null` removes one. Layout reads the registry
 * when it sets a listing, so register before building; in a web worker
 * (the Sandbox lays out in one) register inside the worker.
 */
export declare function registerCodeHighlighter(lang: string, fn: CodeHighlighter | null): void;
/** Whether the built-in tokenizer reads `lang`. */
export declare function builtinCodeLanguage(lang: string | undefined): boolean;
/**
 * The tokens of a listing's lines: a registered highlighter's (for its
 * language, then `'*'`), else the built-in tokenizer's when `builtin` and
 * it reads the language. Undefined when nothing colours it. A
 * highlighter's lines that do not join into the listing's own are left
 * out (the listing is then set plain).
 */
export declare function highlightCode(code: string, lang: string | undefined, builtin: boolean): CodeToken[][] | undefined;
//# sourceMappingURL=highlight.d.ts.map