Function toPattern

src/Kit.ts:656–670

(range: CharRangeRepr)

  @see `Charset.fromPattern`
  */
  export function toPattern(range: CharRangeRepr): string {
    let r1 = begin(range);
    let r2 = end(range);
    if (r1 === r2) return toChar(r1);
    if (r1 + 1 === r2) return toChar(r1) + toChar(r2);
    return toChar(r1) + '-' + toChar(r2);

    function toChar(cp: number): string {
      if (cp === _escapeCodePoint || cp === _excludeSignCodePoint || cp === _hyphenCodePoint) {
        return '\\' + chr(cp);
      } else {
        return chr(cp);
      }
    }
  }

  export function toCodePoints(range: CharRangeRepr, maxCount = Infinity): number[] {
    let r1 = begin(range);