LibTest/core/RegExp/Pattern_semantics/firstMatch_Term_A01_t01.dart

// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

/// @assertion 15.10.2.5: An Atom followed by a Quantifier is repeated the
/// number of times specified by the Quantifier. A Quantifier can be non-greedy,
/// in which case the Atom pattern is repeated as few times as possible while
/// still matching the sequel, or it can be greedy, in which case the Atom
/// pattern is repeated as many times as possible while still matching the
/// sequel. The Atom pattern is repeated rather than the input String that it
/// matches, so different repetitions of the Atom can match different input
/// substrings.
/// @description Checks that greedy and non-greedy quantifiers work as expected.
/// @3rdparty sputnik-v1:S15.10.2.5_A1_T1.js-S15.10.2.5_A1_T2.js
/// @author rodionov

import "../../../../Utils/expect.dart";
 

main() {
  check("a[a-z]{2,4}", "abcdefghi", ["abcde"]);
  check("a[a-z]{2,4}?", "abcdefghi", ["abc"]);
}
  
void check(String pattern, String str, List<String> expectedGroups) {
  RegExp re = new RegExp(pattern);
  Expect.isNotNull(re.firstMatch(str));
  Match fm = re.firstMatch(str) as Match;
  if(null != expectedGroups) {
    Expect.equals(expectedGroups.length, fm.groupCount + 1);
    
    for(int i = 0; i <= fm.groupCount; i++) {
      String? expGr = expectedGroups[i];
      String? actGr = fm.group(i);
      Expect.equals(expGr, actGr,
          "Mismatch at group $i: \"$expGr\" expected instead of \"$actGr\"");
    }
  }
}