| /* |
| * 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: The form (?= Disjunction ) specifies a zero-width |
| * positive lookahead. In order for it to succeed, the pattern inside |
| * Disjunction must match at the current position, but the current |
| * position is not advanced before matching the sequel. If |
| * Disjunction can match at the current position in several ways, |
| * only the first one is tried. Unlike other regular expression |
| * operators, there is no backtracking into a (?= form (this unusual |
| * behaviour is inherited from Perl). This only matters when the |
| * Disjunction contains capturing parentheses and the sequel of the |
| * pattern contains backreferences to those captures. |
| * @description Checks that this syntax works as specified. |
| * @3rdparty sputnik-v1:S15.10.2.8_A1_T1.js-S15.10.2.8_A1_T5.js |
| * @author rodionov |
| * @needsreview Undocumented behavior of the regular expression with an error |
| * @reviewer msyabro |
| */ |
| import "../../../../Utils/expect.dart"; |
| |
| |
| main() { |
| check(r"(?=(a+))", "baaabac", 1, ["", "aaa"]); |
| check(r"(?=(a+))a*b\1", "baaabac", 3, ["aba", "a"]); |
| check(r"[Jj]ava([Ss]cript)?(?=\:)", "just Javascript: the way 0f jedi", 5, ["Javascript", "script"]); |
| check(r"[Jj]ava([Ss]cript)?(?=\:)", "taste of java: the cookbook", 9, ["java", null]); |
| checkNeg(r"[Jj]ava([Ss]cript)?(?=\:)", "rhino is JavaScript engine"); |
| checkNeg(r"a(?=b)a", "aba"); |
| checkNeg(r"(?=a)b\1", "aabb"); |
| } |
| |
| void check(String pattern, String str, int matchPos, List<String> expectedGroups) { |
| RegExp re = new RegExp(pattern); |
| Match fm = re.firstMatch(str); |
| if(null == fm) { |
| Expect.fail("\"$pattern\" !~ \"$str\""); |
| } |
| 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); |
| if(expGr != actGr) { |
| Expect.fail("Mismatch at group $i: \"$expGr\" expected instead of \"$actGr\""); |
| } |
| } |
| } |
| } |
| |
| void checkNeg(String pattern, String str) { |
| RegExp re = new RegExp(pattern); |
| if(null != re.firstMatch(str)) { |
| Expect.fail("\"$pattern\" ~ \"$str\""); |
| } |
| } |
| |
| void checkEx(String pattern, String str) { |
| bool fail = false; |
| try { |
| RegExp re = new RegExp(pattern); |
| re.firstMatch(str); |
| fail = true; |
| } catch(ok) {} |
| if(fail == true) { |
| Expect.fail("An error expected"); |
| } |
| } |