import { MilkdownPlugin } from '@milkdown/kit/ctx';
import { Info, State } from 'mdast-util-to-markdown';
import { Parents } from 'mdast';
/**
 * ProseMirror mark registered as `highlight` in the schema.
 *
 * - **DOM** — Renders as `<mark>` so HTML paste and copy round-trip with the same tag.
 * - **Markdown** — Expects companion mdast nodes with `type: 'highlight'` (produced by the remark
 *   transform below, not by stock GFM). Serializes back through `toMarkdown` + the custom stringify
 *   handler in `configure.ts`.
 */
export declare const highlightSchema: import('@milkdown/utils').$MarkSchema<"highlight">;
/** Command used by the formatting toolbar; toggles the highlight mark on the active selection. */
export declare const toggleHighlightCommand: import('@milkdown/utils').$Command<unknown>;
/**
 * When the user types closing `==` after `==some text`, wraps the inner span in the highlight mark
 * and strips the delimiters (same idea as GFM `~~` strikethrough input rules).
 *
 * Regex groups: `(==)` `([^=\n]+)` `\1` — `markRule` uses the **last** capture group as the marked
 * span, so the middle group must be the highlighted text. Lookbehind/lookahead avoid matching four
 * or more equals in a row as a single highlight.
 */
export declare const highlightInputRule: import('@milkdown/utils').$InputRule;
/**
 * Remark/unified plugin: mutates the mdast between parse and the Milkdown schema parser.
 * Must run in the remark pipeline **before** the document is converted to ProseMirror.
 */
export declare const remarkHighlightSyntax: import('@milkdown/utils').$Remark<"brainfish-highlight-syntax", unknown>;
/**
 * Passed into `remarkStringifyOptionsCtx.unsafe` in `configure.ts`.
 * Declares that `=` may appear in phrasing in ways that are “unsafe” by default but are intentional
 * for our `==highlight==` delimiter pair.
 */
export declare const highlightMdastUnsafe: {
    character: string;
    inConstruct: "phrasing";
    notInConstruct: ("autolink" | "destinationLiteral" | "destinationRaw" | "reference" | "titleQuote" | "titleApostrophe")[];
}[];
/**
 * Serializes mdast `highlight` nodes to markdown `==...==`.
 *
 * Mirrors the structure of GFM strikethrough’s `delete` handler: tracker + `containerPhrasing` keep
 * line wrapping and nesting correct. `state.enter('highlight', …)` is cast because mdast’s
 * `ConstructName` union does not include our custom node name.
 */
export declare function highlightMarkdownHandler(node: Parents, _: unknown, state: State, info: Info): string;
/**
 * All Milkdown plugins for this feature, in registration order:
 * 1. Remark transform (syntax in mdast)
 * 2. Mark schema
 * 3. Input rule
 * 4. Toggle command
 */
export declare const textHighlightPlugin: MilkdownPlugin[];