| // 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 15.10.2.9: An escape sequence of the form \ followed by a nonzero |
| /// decimal number n matches the result of the Nth set of capturing parentheses |
| /// (see 15.10.2.11). It is an error if the regular expression has fewer than n |
| /// capturing parentheses. If the regular expression has n or more capturing |
| /// parentheses but the Nth one is undefined because it has not captured |
| /// anything, then the backreference always succeeds. |
| /// @description Checks that backreferences work as specified. |
| /// @3rdparty sputnik-v1:S15.10.2.9_A1_T1.js-S15.10.2.9_A1_T5.js |
| /// @author rodionov |
| |
| import "../../../../Utils/expect.dart"; |
| |
| |
| main() { |
| check(r"\b(\w+) \1\b", "do you listen the the band", 14, ["the the", "the"]); |
| check(r"([xu]\d{2}([A-H]{2})?)\1", "x09x12x01x01u00FFu00FFx04x04x23", 6, |
| ["x01x01", "x01", null]); |
| check(r"([xu]\d{2}([A-H]{2})?)\1", "x09x12x01x05u00FFu00FFx04x04x23", 12, |
| ["u00FFu00FF", "u00FF", "FF"]); |
| check(r"(a*)b\1+", "baaac", 0, ["b", ""]); |
| checkNeg(r"(a*)b\2", "aaaaaaaaab"); |
| } |
| |
| 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 \"$actGr\""); |
| } |
| } |
| } |
| |
| void checkNeg(String pattern, String str) { |
| RegExp re = new RegExp(pattern); |
| Expect.isNull(re.firstMatch(str), "\"$pattern\" ~ \"$str\""); |
| } |