Include RE2 library

third_party/re2/re2/testing/string_generator.h

Index: third_party/re2/re2/testing/string_generator.h
diff --git a/third_party/re2/re2/testing/string_generator.h b/third_party/re2/re2/testing/string_generator.h
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+// Copyright 2008 The RE2 Authors.  All Rights Reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// String generator: generates all possible strings of up to
+// maxlen letters using the set of letters in alpha.
+// Fetch strings using a Java-like Next()/HasNext() interface.
+
+#ifndef RE2_TESTING_STRING_GENERATOR_H__
+#define RE2_TESTING_STRING_GENERATOR_H__
+
+#include <string>
+#include <vector>
+#include "util/util.h"
+#include "util/random.h"
+#include "re2/stringpiece.h"
+
+namespace re2 {
+
+class StringGenerator {
+ public:
+  StringGenerator(int maxlen, const vector<string>& alphabet);
+  ~StringGenerator();
+  const StringPiece& Next();
+  bool HasNext() { return hasnext_; }
+
+  // Resets generator to start sequence over.
+  void Reset();
+
+  // Causes generator to emit random strings for next n calls to Next().
+  void Random(int32 seed, int n);
+
+  // Causes generator to emit a NULL as the next call.
+  void GenerateNULL();
+
+ private:
+  bool IncrementDigits();
+  bool RandomDigits();
+
+  // Global state.
+  int maxlen_;               // Maximum length string to generate.
+  vector<string> alphabet_;  // Alphabet, one string per letter.
+
+  // Iteration state.
+  StringPiece sp_;           // Last StringPiece returned by Next().
+  string s_;                 // String data in last StringPiece returned by Next().
+  bool hasnext_;             // Whether Next() can be called again.
+  vector<int> digits_;       // Alphabet indices for next string.
+  bool generate_null_;       // Whether to generate a NULL StringPiece next.
+  bool random_;              // Whether generated strings are random.
+  int nrandom_;              // Number of random strings left to generate.
+  ACMRandom* acm_;           // Random number generator
+  DISALLOW_EVIL_CONSTRUCTORS(StringGenerator);
+};
+
+}  // namespace re2
+
+#endif  // RE2_TESTING_STRING_GENERATOR_H__