1 // Copyright 2008 The RE2 Authors. All Rights Reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
5 // String generator: generates all possible strings of up to
6 // maxlen letters using the set of letters in alpha.
7 // Fetch strings using a Java-like Next()/HasNext() interface.
9 #ifndef RE2_TESTING_STRING_GENERATOR_H__
10 #define RE2_TESTING_STRING_GENERATOR_H__
14 #include "util/util.h"
15 #include "util/random.h"
16 #include "re2/stringpiece.h"
20 class StringGenerator {
22 StringGenerator(int maxlen, const vector<string>& alphabet);
24 const StringPiece& Next();
25 bool HasNext() { return hasnext_; }
27 // Resets generator to start sequence over.
30 // Causes generator to emit random strings for next n calls to Next().
31 void Random(int32 seed, int n);
33 // Causes generator to emit a NULL as the next call.
37 bool IncrementDigits();
41 int maxlen_; // Maximum length string to generate.
42 vector<string> alphabet_; // Alphabet, one string per letter.
45 StringPiece sp_; // Last StringPiece returned by Next().
46 string s_; // String data in last StringPiece returned by Next().
47 bool hasnext_; // Whether Next() can be called again.
48 vector<int> digits_; // Alphabet indices for next string.
49 bool generate_null_; // Whether to generate a NULL StringPiece next.
50 bool random_; // Whether generated strings are random.
51 int nrandom_; // Number of random strings left to generate.
52 ACMRandom* acm_; // Random number generator
53 DISALLOW_EVIL_CONSTRUCTORS(StringGenerator);
58 #endif // RE2_TESTING_STRING_GENERATOR_H__