1 //
2 // Copyright 2017 The Abseil Authors.
3 //
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
7 //
8 // https://www.apache.org/licenses/LICENSE-2.0
9 //
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
15 //
16 // -----------------------------------------------------------------------------
17 // File: match.h
18 // -----------------------------------------------------------------------------
19 //
20 // This file contains simple utilities for performing string matching checks.
21 // All of these function parameters are specified as `absl::string_view`,
22 // meaning that these functions can accept `std::string`, `absl::string_view` or
23 // NUL-terminated C-style strings.
24 //
25 // Examples:
26 // std::string s = "foo";
27 // absl::string_view sv = "f";
28 // assert(absl::StrContains(s, sv));
29 //
30 // Note: The order of parameters in these functions is designed to mimic the
31 // order an equivalent member function would exhibit;
32 // e.g. `s.Contains(x)` ==> `absl::StrContains(s, x).
33 #ifndef ABSL_STRINGS_MATCH_H_
34 #define ABSL_STRINGS_MATCH_H_
35
36 #include <cstring>
37
38 #include "absl/strings/string_view.h"
39
40 namespace absl {
41 ABSL_NAMESPACE_BEGIN
42
43 // StrContains()
44 //
45 // Returns whether a given string `haystack` contains the substring `needle`.
StrContains(absl::string_view haystack,absl::string_view needle)46 inline bool StrContains(absl::string_view haystack,
47 absl::string_view needle) noexcept {
48 return haystack.find(needle, 0) != haystack.npos;
49 }
50
StrContains(absl::string_view haystack,char needle)51 inline bool StrContains(absl::string_view haystack, char needle) noexcept {
52 return haystack.find(needle) != haystack.npos;
53 }
54
55 // StartsWith()
56 //
57 // Returns whether a given string `text` begins with `prefix`.
StartsWith(absl::string_view text,absl::string_view prefix)58 inline bool StartsWith(absl::string_view text,
59 absl::string_view prefix) noexcept {
60 return prefix.empty() ||
61 (text.size() >= prefix.size() &&
62 memcmp(text.data(), prefix.data(), prefix.size()) == 0);
63 }
64
65 // EndsWith()
66 //
67 // Returns whether a given string `text` ends with `suffix`.
EndsWith(absl::string_view text,absl::string_view suffix)68 inline bool EndsWith(absl::string_view text,
69 absl::string_view suffix) noexcept {
70 return suffix.empty() ||
71 (text.size() >= suffix.size() &&
72 memcmp(text.data() + (text.size() - suffix.size()), suffix.data(),
73 suffix.size()) == 0);
74 }
75
76 // EqualsIgnoreCase()
77 //
78 // Returns whether given ASCII strings `piece1` and `piece2` are equal, ignoring
79 // case in the comparison.
80 bool EqualsIgnoreCase(absl::string_view piece1,
81 absl::string_view piece2) noexcept;
82
83 // StartsWithIgnoreCase()
84 //
85 // Returns whether a given ASCII string `text` starts with `prefix`,
86 // ignoring case in the comparison.
87 bool StartsWithIgnoreCase(absl::string_view text,
88 absl::string_view prefix) noexcept;
89
90 // EndsWithIgnoreCase()
91 //
92 // Returns whether a given ASCII string `text` ends with `suffix`, ignoring
93 // case in the comparison.
94 bool EndsWithIgnoreCase(absl::string_view text,
95 absl::string_view suffix) noexcept;
96
97 ABSL_NAMESPACE_END
98 } // namespace absl
99
100 #endif // ABSL_STRINGS_MATCH_H_
101