/**
 * Output filter methods.
 *
 * @module output
 * @since 3.2.0
 */
export interface OutputFilterMeta {
    /**
     * The current output.
     */
    output: string;
    /**
     * The original output before it went through the filters.
     */
    original: string;
    /**
     * Style information: whether the output will be printed bold and/or italic.
     */
    style: {
        bold: boolean;
        italic: boolean;
    };
}
export declare type OutputFilter = (input: string, meta: OutputFilterMeta) => boolean;
/**
 * Registers a new output filter.
 *
 * @param filter  The output filter to add.
 * @returns  A function that can be called to remove the filter
 *
 * @see https://vorple-if.com/docs/filters.html
 */
export declare function addOutputFilter(filter: OutputFilter): () => boolean;
/**
 * Runs output through all output filters.
 *
 * @param originalOutput  The original output
 * @internal
 */
export declare function applyOutputFilters(originalOutput: string, meta: OutputFilterMeta): string;
/**
 * Removes a filter from the registered output filters.
 *
 * @param filter  A reference to the filter to remove
 * @returns Returns true if the filter was removed, false if the filter wasn't registered.
 */
export declare function removeOutputFilter(filter: OutputFilter): boolean;