/** @module util */
/**
 * Unescape a string/text value used in a GTF attribute.
 * Textual attributes should be surrounded by double quotes
 * source info:
 * https://mblab.wustl.edu/GTF22.html
 * https://en.wikipedia.org/wiki/Gene_transfer_format
 *
 * @param {String} s
 * @returns {String}
 */
export declare function unescape(s: any): string | null;
export declare function escape(s: any): string;
/**
 * Escape a value for use in a GTF column value.
 *
 * @param {String} s
 * @returns {String}
 */
export declare function escapeColumn(s: any): string;
/**
 * Parse the 9th column (attributes) of a GTF feature line.
 *
 * @param {String} attrString
 * @returns {Object}
 */
export declare function parseAttributes(attrString: any): {};
/**
 * Parse a GTF feature line.
 *
 * @param {String} line
 * returns the parsed line in an object
 */
export declare function parseFeature(line: any): {};
/**
 * Parse a GTF directive/comment line.
 *
 * @param {String} line
 * @returns {Object} the information in the directive
 */
export declare function parseDirective(line: any): {
    directive: string;
} | null;
/**
 * Format an attributes object into a string suitable for the 9th column of GTF.
 *
 * @param {Object} attrs
 */
export declare function formatAttributes(attrs: any): string;
/**
 * Format a feature object or array of
 * feature objects into one or more lines of GTF.
 *
 * @param {Object|Array[Object]} featureOrFeatures
 */
export declare function formatFeature(featureOrFeatures: any): any;
/**
 * Format a directive into a line of GTF.
 *
 * @param {Object} directive
 * @returns {String}
 */
export declare function formatDirective(directive: any): string;
/**
 * Format a comment into a GTF comment.
 * Yes I know this is just adding a # and a newline.
 *
 * @param {Object} comment
 * @returns {String}
 */
export declare function formatComment(comment: any): string;
/**
 * Format a sequence object as FASTA
 *
 * @param {Object} seq
 * @returns {String} formatted single FASTA sequence
 */
export declare function formatSequence(seq: any): string;
/**
 * Format a directive, comment, or feature,
 * or array of such items, into one or more lines of GTF.
 *
 * @param {Object|Array} itemOrItems
 */
export declare function formatItem(itemOrItems: any): any;