/**
 * {@link RichDoc} → markdown — the serializer (inverse of `mdToDoc`).
 *
 * Segments the flat text by `blocks[]` (raw chunks verbatim; heading / list /
 * blockquote / codeBlock lines get their markers re-synthesized — markers are
 * never in the doc text; remaining lines as paragraphs), then serializes
 * inline spans per segment via elementary runs + a close/reopen delimiter
 * stack (valid nesting from arbitrarily overlapping spans).
 *
 * Consecutive same-kind block lines join into one group (`\n`-separated:
 * a tight list, one quote, one fence); groups separate with blank lines.
 * Ordered numbering derives from the run position, restarting at each run's
 * first-line `level` (a non-1 start) — so two adjacent ordered runs merge
 * into one list (the flat model has no list-boundary marker; documented
 * normalization, idempotent).
 *
 * Round-trip contract: `mdToDoc(docToMd(doc))` is structurally equal to a
 * *normalized* `doc` — emphasis markers, hard breaks (→ paragraph breaks), and
 * blank lines normalize; `raw` blocks round-trip byte-for-byte.
 */
import type { InlineSpan, RichDoc } from '@sigx/lynx-richtext';
/** Serialize one plugin-owned span back to markdown (a plugin's `inline.serialize`). */
export type SpanSerializer = (span: InlineSpan, text: string) => string;
export interface DocToMdOptions {
    /**
     * Plugin serializers keyed by the span type they own
     * (`docMapping.spanType`). A plugin-owned span is emitted **atomically**:
     * the serializer's output replaces the covered text entirely.
     */
    serializers?: ReadonlyMap<string, SpanSerializer>;
}
export declare function docToMd(doc: RichDoc, options?: DocToMdOptions): string;