OLD | NEW |
(Empty) | |
| 1 // Copyright (C) 2011 Google Inc. |
| 2 // |
| 3 // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 // you may not use this file except in compliance with the License. |
| 5 // You may obtain a copy of the License at |
| 6 // |
| 7 // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 // |
| 9 // Unless required by applicable law or agreed to in writing, software |
| 10 // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 // See the License for the specific language governing permissions and |
| 13 // limitations under the License. |
| 14 |
| 15 // Author: George Yakovlev |
| 16 // Philippe Liard |
| 17 |
| 18 #include "regexp_adapter.h" |
| 19 |
| 20 #include <cstddef> |
| 21 #include <string> |
| 22 |
| 23 #include <re2/re2.h> |
| 24 #include <re2/stringpiece.h> |
| 25 |
| 26 #include "base/basictypes.h" |
| 27 #include "base/logging.h" |
| 28 #include "stringutil.h" |
| 29 |
| 30 namespace i18n { |
| 31 namespace phonenumbers { |
| 32 |
| 33 using re2::StringPiece; |
| 34 |
| 35 // Implementation of RegExpInput abstract class. |
| 36 class RE2RegExpInput : public RegExpInput { |
| 37 public: |
| 38 explicit RE2RegExpInput(const string& utf8_input) |
| 39 : string_(utf8_input), |
| 40 utf8_input_(string_) {} |
| 41 |
| 42 virtual string ToString() const { |
| 43 return utf8_input_.ToString(); |
| 44 } |
| 45 |
| 46 StringPiece* Data() { |
| 47 return &utf8_input_; |
| 48 } |
| 49 |
| 50 private: |
| 51 // string_ holds the string referenced by utf8_input_ as StringPiece doesn't |
| 52 // copy the string passed in. |
| 53 const string string_; |
| 54 StringPiece utf8_input_; |
| 55 }; |
| 56 |
| 57 namespace { |
| 58 |
| 59 template <typename Function, typename Input> |
| 60 bool DispatchRE2Call(Function regex_function, |
| 61 Input input, |
| 62 const RE2& regexp, |
| 63 string* out1, |
| 64 string* out2, |
| 65 string* out3) { |
| 66 if (out3) { |
| 67 return regex_function(input, regexp, out1, out2, out3); |
| 68 } |
| 69 if (out2) { |
| 70 return regex_function(input, regexp, out1, out2); |
| 71 } |
| 72 if (out1) { |
| 73 return regex_function(input, regexp, out1); |
| 74 } |
| 75 return regex_function(input, regexp); |
| 76 } |
| 77 |
| 78 // Replaces unescaped dollar-signs with backslashes. Backslashes are deleted |
| 79 // when they escape dollar-signs. |
| 80 string TransformRegularExpressionToRE2Syntax(const string& regex) { |
| 81 string re2_regex(regex); |
| 82 if (GlobalReplaceSubstring("$", "\\", &re2_regex) == 0) { |
| 83 return regex; |
| 84 } |
| 85 // If we replaced a dollar sign with a backslash and there are now two |
| 86 // backslashes in the string, we assume that the dollar-sign was previously |
| 87 // escaped and that we need to retain it. To do this, we replace pairs of |
| 88 // backslashes with a dollar sign. |
| 89 GlobalReplaceSubstring("\\\\", "$", &re2_regex); |
| 90 return re2_regex; |
| 91 } |
| 92 |
| 93 } // namespace |
| 94 |
| 95 // Implementation of RegExp abstract class. |
| 96 class RE2RegExp : public RegExp { |
| 97 public: |
| 98 explicit RE2RegExp(const string& utf8_regexp) |
| 99 : utf8_regexp_(utf8_regexp) {} |
| 100 |
| 101 virtual bool Consume(RegExpInput* input_string, |
| 102 bool anchor_at_start, |
| 103 string* matched_string1, |
| 104 string* matched_string2, |
| 105 string* matched_string3) const { |
| 106 DCHECK(input_string); |
| 107 StringPiece* utf8_input = |
| 108 static_cast<RE2RegExpInput*>(input_string)->Data(); |
| 109 |
| 110 if (anchor_at_start) { |
| 111 return DispatchRE2Call(RE2::Consume, utf8_input, utf8_regexp_, |
| 112 matched_string1, matched_string2, |
| 113 matched_string3); |
| 114 } else { |
| 115 return DispatchRE2Call(RE2::FindAndConsume, utf8_input, utf8_regexp_, |
| 116 matched_string1, matched_string2, |
| 117 matched_string3); |
| 118 } |
| 119 } |
| 120 |
| 121 virtual bool Match(const string& input_string, |
| 122 bool full_match, |
| 123 string* matched_string) const { |
| 124 if (full_match) { |
| 125 return DispatchRE2Call(RE2::FullMatch, input_string, utf8_regexp_, |
| 126 matched_string, NULL, NULL); |
| 127 } else { |
| 128 return DispatchRE2Call(RE2::PartialMatch, input_string, utf8_regexp_, |
| 129 matched_string, NULL, NULL); |
| 130 } |
| 131 } |
| 132 |
| 133 virtual bool Replace(string* string_to_process, |
| 134 bool global, |
| 135 const string& replacement_string) const { |
| 136 DCHECK(string_to_process); |
| 137 const string re2_replacement_string = |
| 138 TransformRegularExpressionToRE2Syntax(replacement_string); |
| 139 if (global) { |
| 140 return RE2::GlobalReplace(string_to_process, utf8_regexp_, |
| 141 re2_replacement_string); |
| 142 } else { |
| 143 return RE2::Replace(string_to_process, utf8_regexp_, |
| 144 re2_replacement_string); |
| 145 } |
| 146 } |
| 147 |
| 148 private: |
| 149 RE2 utf8_regexp_; |
| 150 }; |
| 151 |
| 152 // Implementation of the adapter static factory methods. |
| 153 // RE2 RegExp engine is the default implementation. |
| 154 RegExpInput* RegExpInput::Create(const string& utf8_input) { |
| 155 return new RE2RegExpInput(utf8_input); |
| 156 } |
| 157 |
| 158 RegExp* RegExp::Create(const string& utf8_regexp) { |
| 159 return new RE2RegExp(utf8_regexp); |
| 160 } |
| 161 |
| 162 } // namespace phonenumbers |
| 163 } // namespace i18n |
OLD | NEW |