sS regexpForFloatingPointWithoutSign_v2() {
  S startingWithDigit = [[\d+(\.\d*)?]];
  S startingWithDot = [[\.\d+]];
  S optExp = [[([eE][+-]?\d+)?]];
  ret "(" + startingWithDigit + "|" + startingWithDot + ")" + optExp;
}