third_party/WebKit/Source/wtf/text/IntegerToStringConversion.h

   1 /*
   2  * Copyright (C) 2012 Apple Inc. All Rights Reserved.
   3  * Copyright (C) 2012 Patrick Gansterer <paroga@paroga.com>
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Library General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Library General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Library General Public License
  16  * along with this library; see the file COPYING.LIB.  If not, write to
  17  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  18  * Boston, MA 02110-1301, USA.
  19  *
  20  */
  21
  22 #ifndef IntegerToStringConversion_h
  23 #define IntegerToStringConversion_h
  24
  25 #include "wtf/text/StringBuilder.h"
  26 #include "wtf/text/StringImpl.h"
  27
  28 namespace WTF {
  29
  30 enum PositiveOrNegativeNumber {
  31     PositiveNumber,
  32     NegativeNumber
  33 };
  34
  35 template<typename T> struct ConversionTrait;
  36
  37 template<> struct ConversionTrait<String> {
  38     typedef PassRefPtr<StringImpl> ReturnType;
  39     typedef void AdditionalArgumentType;
  40     static inline ReturnType flush(LChar* characters, unsigned length, void*) { return StringImpl::create(characters, length); }
  41 };
  42 template<> struct ConversionTrait<StringBuilder> {
  43     typedef void ReturnType;
  44     typedef StringBuilder AdditionalArgumentType;
  45     static inline ReturnType flush(LChar* characters, unsigned length, StringBuilder* stringBuilder) { stringBuilder->append(characters, length); }
  46 };
  47 template<> struct ConversionTrait<AtomicString> {
  48     typedef AtomicString ReturnType;
  49     typedef void AdditionalArgumentType;
  50     static inline ReturnType flush(LChar* characters, unsigned length, void*) { return AtomicString(characters, length); }
  51 };
  52
  53 template<typename T> struct UnsignedIntegerTrait;
  54
  55 template<> struct UnsignedIntegerTrait<int> {
  56     typedef unsigned Type;
  57 };
  58 template<> struct UnsignedIntegerTrait<long> {
  59     typedef unsigned long Type;
  60 };
  61 template<> struct UnsignedIntegerTrait<long long> {
  62     typedef unsigned long long Type;
  63 };
  64
  65 template<typename T, typename UnsignedIntegerType, PositiveOrNegativeNumber NumberType>
  66 static typename ConversionTrait<T>::ReturnType numberToStringImpl(UnsignedIntegerType number, typename ConversionTrait<T>::AdditionalArgumentType* additionalArgument)
  67 {
  68     LChar buf[sizeof(UnsignedIntegerType) * 3 + 1];
  69     LChar* end = buf + WTF_ARRAY_LENGTH(buf);
  70     LChar* p = end;
  71
  72     do {
  73         *--p = static_cast<LChar>((number % 10) + '0');
  74         number /= 10;
  75     } while (number);
  76
  77     if (NumberType == NegativeNumber)
  78         *--p = '-';
  79
  80     return ConversionTrait<T>::flush(p, static_cast<unsigned>(end - p), additionalArgument);
  81 }
  82
  83 template<typename T, typename SignedIntegerType>
  84 inline typename ConversionTrait<T>::ReturnType numberToStringSigned(SignedIntegerType number, typename ConversionTrait<T>::AdditionalArgumentType* additionalArgument = 0)
  85 {
  86     if (number < 0)
  87         return numberToStringImpl<T, typename UnsignedIntegerTrait<SignedIntegerType>::Type, NegativeNumber>(-number, additionalArgument);
  88     return numberToStringImpl<T, typename UnsignedIntegerTrait<SignedIntegerType>::Type, PositiveNumber>(number, additionalArgument);
  89 }
  90
  91 template<typename T, typename UnsignedIntegerType>
  92 inline typename ConversionTrait<T>::ReturnType numberToStringUnsigned(UnsignedIntegerType number, typename ConversionTrait<T>::AdditionalArgumentType* additionalArgument = 0)
  93 {
  94     return numberToStringImpl<T, UnsignedIntegerType, PositiveNumber>(number, additionalArgument);
  95 }
  96
  97 } // namespace WTF
  98
  99 #endif // IntegerToStringConversion_h