code: function rangeToPattern(start, stop, options) {
    if (start === stop) {
      return { pattern: start, count: [], digits: 0 };
    }
  
    let zipped = zip(start, stop);
    let digits = zipped.length;
    let pattern = '';
    let count = 0;
  
    for (let i = 0; i < digits; i++) {
      let [startDigit, stopDigit] = zipped[i];
  
      if (startDigit === stopDigit) {
        pattern += startDigit;
  
      } else if (startDigit !== '0' || stopDigit !== '9') {
        pattern += toCharacterClass(startDigit, stopDigit, options);
  
      } else {
        count++;
      }
    }
  
    if (count) {
      pattern += options.shorthand === true ? '\\d' : '[0-9]';
    }
  
    return { pattern, count: [count], digits };
  }
docs: Convert a range to a regex pattern
  @param {Number} `start`
  @param {Number} `stop`
  @return {String}