// Copyright JS Foundation and other contributors, http://js.foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

var r;

r = new RegExp ("(a)b\\1").exec("aba");
assert (r[0] == "aba");
assert (r[1] == "a");

r = new RegExp ("(a)b\\1").exec("b");
assert (r == undefined);

r = new RegExp ("(a)*b\\1").exec("b");
assert (r[0] == "b");
assert (r[1] == undefined);

assert (JSON.stringify (/[[]?(a)\1/.exec("aa")) === '["aa","a"]');
assert (JSON.stringify (/\1{2,5}()\B/.exec("asd")) === '["",""]');