1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // <regex>
11 
12 // template <class BidirectionalIterator, class Allocator, class charT, class traits>
13 //     bool
14 //     regex_match(BidirectionalIterator first, BidirectionalIterator last,
15 //                  match_results<BidirectionalIterator, Allocator>& m,
16 //                  const basic_regex<charT, traits>& e,
17 //                  regex_constants::match_flag_type flags = regex_constants::match_default);
18 
19 // std::regex in ECMAScript mode should not ignore capture groups inside lookahead assertions.
20 // For example, matching /(?=(a))(a)/ to "a" should yield two captures: \1 = "a", \2 = "a"
21 
22 #include <regex>
23 #include <cassert>
24 
25 #include "test_iterators.h"
26 
main()27 int main()
28 {
29     {
30         std::regex re("^(?=(.))a$");
31         assert(re.mark_count() == 1);
32 
33         std::string s("a");
34         std::smatch m;
35         assert(std::regex_match(s, m, re));
36         assert(m.size() == 2);
37         assert(m[0] == "a");
38         assert(m[1] == "a");
39     }
40 
41     {
42         std::regex re("^(a)(?=(.))(b)$");
43         assert(re.mark_count() == 3);
44 
45         std::string s("ab");
46         std::smatch m;
47         assert(std::regex_match(s, m, re));
48         assert(m.size() == 4);
49         assert(m[0] == "ab");
50         assert(m[1] == "a");
51         assert(m[2] == "b");
52         assert(m[3] == "b");
53     }
54 
55     {
56         std::regex re("^(.)(?=(.)(?=.(.)))(...)$");
57         assert(re.mark_count() == 4);
58 
59         std::string s("abcd");
60         std::smatch m;
61         assert(std::regex_match(s, m, re));
62         assert(m.size() == 5);
63         assert(m[0] == "abcd");
64         assert(m[1] == "a");
65         assert(m[2] == "b");
66         assert(m[3] == "d");
67         assert(m[4] == "bcd");
68     }
69 
70     {
71         std::regex re("^(a)(?!([^b]))(.c)$");
72         assert(re.mark_count() == 3);
73 
74         std::string s("abc");
75         std::smatch m;
76         assert(std::regex_match(s, m, re));
77         assert(m.size() == 4);
78         assert(m[0] == "abc");
79         assert(m[1] == "a");
80         assert(m[2] == "");
81         assert(m[3] == "bc");
82     }
83 
84     {
85         std::regex re("^(?!((b)))(?=(.))(?!(abc)).b$");
86         assert(re.mark_count() == 4);
87 
88         std::string s("ab");
89         std::smatch m;
90         assert(std::regex_match(s, m, re));
91         assert(m.size() == 5);
92         assert(m[0] == "ab");
93         assert(m[1] == "");
94         assert(m[2] == "");
95         assert(m[3] == "a");
96         assert(m[4] == "");
97     }
98 }
99