* Irregexp: Handle backtrack past look-ahead.

test/mjsunit/regexp-capture.js

+// Copyright 2009 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Tests from http://blog.stevenlevithan.com/archives/npcg-javascript
+
+assertEquals(true, /(x)?\1y/.test("y"));
+assertEquals(["y", undefined], /(x)?\1y/.exec("y"));
+assertEquals(["y", undefined], /(x)?y/.exec("y"));
+assertEquals(["y", undefined], "y".match(/(x)?\1y/));
+assertEquals(["y", undefined], "y".match(/(x)?y/));
+assertEquals(["y"], "y".match(/(x)?\1y/g));
+assertEquals(["", undefined, ""], "y".split(/(x)?\1y/));
+assertEquals(["", undefined, ""], "y".split(/(x)?y/));
+assertEquals(0, "y".search(/(x)?\1y/));
+assertEquals("z", "y".replace(/(x)?\1y/, "z"));
+assertEquals("", "y".replace(/(x)?y/, "$1"));
+assertEquals("undefined", "y".replace(/(x)?\1y/,
+    function($0, $1){ 
+        return String($1); 
+    }));
+assertEquals("undefined", "y".replace(/(x)?y/, 
+    function($0, $1){ 
+        return String($1); 
+    }));
+assertEquals("undefined", "y".replace(/(x)?y/, 
+    function($0, $1){ 
+        return $1; 
+    }));