LibTest/core/RegExp/Pattern_semantics/firstMatch_Atom_A03_t02.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 15.10.2.8: Parentheses of the form ( Disjunction ) serve both to
/// group the components of the Disjunction pattern together and tov save the
/// result of the match. The result can be used either in a backreference (\
/// followed by a nonzero decimal number), referenced in a replace String, or
/// returned as part of a list from the regular expression matching internal
/// procedure.
/// @description Checks nested parentheses.
/// @3rdparty sputnik-v1:S15.10.2.8_A3_T1.js-S15.10.2.8_A3_T33.js
/// @author rodionov

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

main() {
  int parens = 200;
  StringBuffer ptrn = new StringBuffer();
  for(int i = 0; i < parens; i++) {
    ptrn.write("(");
  }
  ptrn.write("hello");
  for(int i = 0; i < parens; i++) {
    ptrn.write(")");
  }
  List<String> exp = List<String>.filled(parens + 1, "hello");
  check(ptrn.toString(), "hello", 0, exp);
}

void check(
    String pattern, String str, int matchPos, List<String> expectedGroups) {
  RegExp re = new RegExp(pattern);
  Expect.isNotNull(re.firstMatch(str), "\"$pattern\" !~ \"$str\"");
  Match fm = re.firstMatch(str) as Match;
  if(matchPos >= 0) {
    Expect.equals(matchPos, fm.start);
  }
  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\"");
    }
  }
}