/**
 * Iframe directive regex pattern for input rule
 * Matches: ::iframe{src="https://example.com"}
 * Supports both straight quotes (") and curly quotes (")
 */
export declare const IFRAME_INPUT_REGEX: RegExp;
/**
 * Input rule: typing ::iframe{src="..."} creates an embed block with embedType 'iframe'
 */
export declare const iframeInputRule: import('@milkdown/utils').$InputRule;