import type { MarkedExtension } from 'marked';
/**
 * Creates a marked extension that tokenizes fenced ` ```mermaid ` code blocks
 * into custom `mermaid` tokens.
 *
 * The extension produces block-level tokens with `{ type: 'mermaid', raw, text }`
 * where `text` is the trimmed diagram source. It has zero runtime dependencies —
 * pair it with `MermaidRenderer` (or your own component) to render the diagrams.
 *
 * @example
 * ```svelte
 * <script lang="ts">
 *   import SvelteMarkdown from '@humanspeak/svelte-markdown'
 *   import { markedMermaid, MermaidRenderer } from '@humanspeak/svelte-markdown'
 *
 *   const renderers = { mermaid: MermaidRenderer }
 * </script>
 *
 * <SvelteMarkdown
 *   source={markdown}
 *   extensions={[markedMermaid()]}
 *   {renderers}
 * />
 * ```
 *
 * @returns A `MarkedExtension` with a single block-level `mermaid` tokenizer
 */
export declare function markedMermaid(): MarkedExtension;