code: function LineColumnFinder(str, options) {
    if (!(this instanceof LineColumnFinder)) {
      if (typeof options === "number") {
        return (new LineColumnFinder(str)).fromIndex(options);
      }
      return new LineColumnFinder(str, options);
    }
  
    this.str = str || "";
    this.lineToIndex = buildLineToIndex(this.str);
  
    options = options || {};
    this.origin = typeof options.origin === "undefined" ? 1 : options.origin;
  }
docs: Finder for index and line-column from given string.
  
  You can call this without `new` operator as it returns an instance anyway.
  
  @class
  @param {string} str - A string to be parsed.
  @param {Object|number} [options] - Options.
  This can be an index in the string for shorthand of `lineColumn(str, index)`.
  @param {number} [options.origin=1] - The origin value of line and column.