grep method

Stream<String> grep(
  1. String regexp,
  2. {bool exclude = false,
  3. bool onlyMatching = false,
  4. bool caseSensitive = true,
  5. bool unicode = false,
  6. bool dotAll = false}

Returns the elements of this that match regexp.

If exclude is true, instead returns the elements of this that don't match regexp.

If onlyMatching is true, this only prints the non-empty matched parts of each line. Prints each match on a separate line. This flag can't be true at the same time as exclude.

The caseSensitive, unicode, and dotAll flags are the same as for new RegExp.


Stream<String> grep(String regexp,
    {bool exclude = false,
    bool onlyMatching = false,
    bool caseSensitive = true,
    bool unicode = false,
    bool dotAll = false}) {
  if (exclude && onlyMatching) {
    throw ArgumentError(
        "The exclude and onlyMatching flags can't both be set");

  var pattern = RegExp(regexp,
      caseSensitive: caseSensitive, unicode: unicode, dotAll: dotAll);

  return onlyMatching
      ? expand((line) => pattern
          .map((match) =>!)
          .where((match) => match.isNotEmpty))
      : where((line) => pattern.hasMatch(line) != exclude);