import type { ImmutableDictionary } from "../util/dictionary.js";
import { type DirectoryElement } from "../util/element.js";
import type { Extractor } from "./Extractor.js";
import { ThroughExtractor } from "./ThroughExtractor.js";
/** Options for a `MergingExtractor`. */
export interface MergingExtractorOptions {
    /**
     * Templated key pairs that should merge. Each key is a `{base}` template matched against the secondary element's key;
     * each value is an ordered list of `{base}` templates for the primary candidates to merge into.
     * - The first primary candidate that exists in the same directory wins; remaining candidates are ignored.
     * - If no candidate exists the secondary is left in place as its own tree-file element.
     * - Defaults to `{ "{base}.md": ["{base}.ts", "{base}.tsx", "{base}.js", "{base}.jsx"] }`.
     */
    readonly merges?: ImmutableDictionary<readonly string[]>;
}
/**
 * Through extractor that walks a `DirectoryElement` tree and merges sibling tree elements whose keys match a `merges` template pair.
 * - Walks every directory recursively, applying the merge at each level.
 * - The primary (winning) element keeps its `key`, `source`, and `type`; the secondary's `title`, `description`,
 *   `content`, and `children` are folded in via `mergeTreeElements()`.
 * - A secondary with no matching primary is left in place — pure prose files (e.g. `concepts.md` with no `concepts.ts`) stand alone.
 */
export declare class MergingExtractor<I> extends ThroughExtractor<I, DirectoryElement> {
    private readonly _merges;
    constructor(source: Extractor<I, DirectoryElement>, { merges }?: MergingExtractorOptions);
    extract(input: I): Promise<DirectoryElement>;
}