docs: function (str, start, end, regexp) {
              var currentCharPos = start, whiteRegexp = regexp || /\s/, currentChar;
              while (currentCharPos < end) {
                  currentChar = str.charAt(currentCharPos);
                  if (whiteRegexp.test(currentChar)) {
                      return currentCharPos;
                  }
                  currentCharPos++;
              }
              return -1;
          }