CPP: Add a regex-adaptor to later allow different reg-ex engines to be used.

cpp/src/regexp_adapter.h

@@ -0,0 +1,161 @@
+// Copyright (C) 2011 Google Inc.
+//
+// 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.
+
+// Author: George Yakovlev
+//         Philippe Liard
+
+// Regexp adapter to allow a pluggable regexp engine. It has been introduced
+// during the integration of the open-source version of this library into
+// Chromium to be able to use the ICU Regex engine instead of RE2, which is not
+// officially supported on Windows.
+// Since RE2 was initially used in this library, the interface of this adapter
+// is very close to the subset of the RE2 API used in phonenumberutil.cc.
+
+#ifndef I18N_PHONENUMBERS_REGEXP_ADAPTER_H_
+#define I18N_PHONENUMBERS_REGEXP_ADAPTER_H_
+
+#include <string>
+
+namespace i18n {
+namespace phonenumbers {
+
+using std::string;
+
+// RegExpInput is the interface that abstracts the input that feeds the
+// Consume() method of RegExp which may differ depending on its various
+// implementations (StringPiece for RE2, UnicodeString for ICU Regex).
+class RegExpInput {
+ public:
+  virtual ~RegExpInput() {}
+
+  // Creates a new instance of the default RegExpInput implementation. The
+  // deletion of the returned instance is under the responsibility of the
+  // caller.
+  static RegExpInput* Create(const string& utf8_input);
+
+  // Converts to a C++ string.
+  virtual string ToString() const = 0;
+};
+
+// The regular expression abstract class. It supports only functions used in
+// phonenumberutil.cc. Consume(), Match() and Replace() methods must be
+// implemented.
+class RegExp {
+ public:
+  virtual ~RegExp() {}
+
+  // Creates a new instance of the default RegExp implementation. The deletion
+  // of the returned instance is under the responsibility of the caller.
+  static RegExp* Create(const string& utf8_regexp);
+
+  // Matches string to regular expression, returns true if expression was
+  // matched, false otherwise, advances position in the match.
+  // input_string - string to be searched.
+  // anchor_at_start - if true, match would be successful only if it appears at
+  // the beginning of the tested region of the string.
+  // matched_string1 - the first string extracted from the match. Can be NULL.
+  // matched_string2 - the second string extracted from the match. Can be NULL.
+  // matched_string3 - the third string extracted from the match. Can be NULL.
+  virtual bool Consume(RegExpInput* input_string,
+                       bool anchor_at_start,
+                       string* matched_string1,
+                       string* matched_string2,
+                       string* matched_string3) const = 0;
+
+  // Helper methods calling the Consume method that assume the match must start
+  // at the beginning.
+  inline bool Consume(RegExpInput* input_string,
+                      string* matched_string1,
+                      string* matched_string2,
+                      string* matched_string3) const {
+    return Consume(input_string, true, matched_string1, matched_string2,
+                   matched_string3);
+  }
+
+  inline bool Consume(RegExpInput* input_string,
+                      string* matched_string1,
+                      string* matched_string2) const {
+    return Consume(input_string, true, matched_string1, matched_string2, NULL);
+  }
+
+  inline bool Consume(RegExpInput* input_string, string* matched_string) const {
+    return Consume(input_string, true, matched_string, NULL, NULL);
+  }
+
+  inline bool Consume(RegExpInput* input_string) const {
+    return Consume(input_string, true, NULL, NULL, NULL);
+  }
+
+  // Helper method calling the Consume method that assumes the match can start
+  // at any place in the string.
+  inline bool FindAndConsume(RegExpInput* input_string,
+                             string* matched_string) const {
+    return Consume(input_string, false, matched_string, NULL, NULL);
+  }
+
+  // Matches string to regular expression, returns true if the expression was
+  // matched, false otherwise.
+  // input_string - string to be searched.
+  // full_match - if true, match would be successful only if it matches the
+  // complete string.
+  // matched_string - the string extracted from the match. Can be NULL.
+  virtual bool Match(const string& input_string,
+                     bool full_match,
+                     string* matched_string) const = 0;
+
+  // Helper methods calling the Match method with the right arguments.
+  inline bool PartialMatch(const string& input_string,
+                           string* matched_string) const {
+    return Match(input_string, false, matched_string);
+  }
+
+  inline bool PartialMatch(const string& input_string) const {
+    return Match(input_string, false, NULL);
+  }
+
+  inline bool FullMatch(const string& input_string,
+                        string* matched_string) const {
+    return Match(input_string, true, matched_string);
+  }
+
+  inline bool FullMatch(const string& input_string) const {
+    return Match(input_string, true, NULL);
+  }
+
+  // Replaces match(es) in 'string_to_process'. If 'global' is true,
+  // replaces all the matches, otherwise only the first match.
+  // replacement_string - text the matches are replaced with. The groups in the
+  // replacement string are referenced with the $[0-9] notation.
+  // Returns true if the pattern matches and a replacement occurs, false
+  // otherwise.
+  virtual bool Replace(string* string_to_process,
+                       bool global,
+                       const string& replacement_string) const = 0;
+
+  // Helper methods calling the Replace method with the right arguments.
+  inline bool Replace(string* string_to_process,
+                      const string& replacement_string) const {
+    return Replace(string_to_process, false, replacement_string);
+  }
+
+  inline bool GlobalReplace(string* string_to_process,
+                            const string& replacement_string) const {
+    return Replace(string_to_process, true, replacement_string);
+  }
+};
+
+}  // namespace phonenumbers
+}  // namespace i18n
+
+#endif  // I18N_PHONENUMBERS_REGEXP_ADAPTER_H_