export declare function delay(milliseconds?: number): Promise<void>;
export declare function isLetter(char: number): boolean;
/**
 * Join a baseUrl to a path, ensuring there is exactly one slash at the join position.
 */
export declare function joinURL(baseUrl: string, path: string): string;
/**
 * Find the longest string that starts all of the supplied strings.
 * startIndex is the index to start at, if you already know that the first startIndex characters
 * are identical.
 */
export declare function longestStartsWith(strings: string[], startIndex?: number): string;
/**
 * Trim whitespace from end of string.
 */
export declare function rtrim(text: string): string;
/**
 * Convert array of char codes to string without exceeding maximum call stack size.
 */
export declare function stringFromCharCodes(codes: number[] | Int8Array): string;
/**
 * Arrange an array of strings into columns that fit within a columnWidth.
 * Each column is the same width.
 * Return an array of lines.
 */
export declare function toColumns(strings: string[], columnWidth: number): string[];