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/*
* Copyright (C) 2007-2019 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <wtf/Assertions.h>
#include <wtf/text/LChar.h>
// The behavior of many of the functions in the <ctype.h> header is dependent
// on the current locale. But in the WebKit project, all uses of those functions
// are in code processing something that's not locale-specific. These equivalents
// for some of the <ctype.h> functions are named more explicitly, not dependent
// on the C library locale, and we should also optimize them as needed.
// All functions return false or leave the character unchanged if passed a character
// that is outside the range 0-7F. So they can be used on Unicode strings or
// characters if the intent is to do processing only if the character is ASCII.
namespace WTF {
template<typename CharacterType> bool isASCII(CharacterType);
template<typename CharacterType> bool isASCIIAlpha(CharacterType);
template<typename CharacterType> bool isASCIIAlphanumeric(CharacterType);
template<typename CharacterType> bool isASCIIBinaryDigit(CharacterType);
template<typename CharacterType> bool isASCIIDigit(CharacterType);
template<typename CharacterType> bool isASCIIHexDigit(CharacterType);
template<typename CharacterType> bool isASCIILower(CharacterType);
template<typename CharacterType> bool isASCIIOctalDigit(CharacterType);
template<typename CharacterType> bool isASCIIPrintable(CharacterType);
template<typename CharacterType> bool isASCIISpace(CharacterType);
template<typename CharacterType> bool isASCIIUpper(CharacterType);
template<typename CharacterType> CharacterType toASCIILower(CharacterType);
template<typename CharacterType> CharacterType toASCIIUpper(CharacterType);
template<typename CharacterType> uint8_t toASCIIHexValue(CharacterType);
template<typename CharacterType> uint8_t toASCIIHexValue(CharacterType firstCharacter, CharacterType secondCharacter);
char lowerNibbleToASCIIHexDigit(uint8_t);
char upperNibbleToASCIIHexDigit(uint8_t);
char lowerNibbleToLowercaseASCIIHexDigit(uint8_t);
char upperNibbleToLowercaseASCIIHexDigit(uint8_t);
template<typename CharacterType> bool isASCIIAlphaCaselessEqual(CharacterType, char expectedASCIILowercaseLetter);
// The toASCIILowerUnchecked function can be used for comparing any input character
// to a lowercase English character. The isASCIIAlphaCaselessEqual function should
// be used for regular comparison of ASCII alpha characters, but switch statements
// in the CSS tokenizer, for example, instead make direct use toASCIILowerUnchecked.
template<typename CharacterType> CharacterType toASCIILowerUnchecked(CharacterType);
extern WTF_EXPORT_PRIVATE const unsigned char asciiCaseFoldTable[256];
template<typename CharacterType> inline bool isASCII(CharacterType character)
{
return !(character & ~0x7F);
}
template<typename CharacterType> inline bool isASCIILower(CharacterType character)
{
return character >= 'a' && character <= 'z';
}
template<typename CharacterType> inline CharacterType toASCIILowerUnchecked(CharacterType character)
{
// This function can be used for comparing any input character
// to a lowercase English character. The isASCIIAlphaCaselessEqual
// below should be used for regular comparison of ASCII alpha
// characters, but switch statements in CSS tokenizer instead make
// direct use of this function.
return character | 0x20;
}
template<typename CharacterType> inline bool isASCIIAlpha(CharacterType character)
{
return isASCIILower(toASCIILowerUnchecked(character));
}
template<typename CharacterType> inline bool isASCIIDigit(CharacterType character)
{
return character >= '0' && character <= '9';
}
template<typename CharacterType> inline bool isASCIIAlphanumeric(CharacterType character)
{
return isASCIIDigit(character) || isASCIIAlpha(character);
}
template<typename CharacterType> inline bool isASCIIHexDigit(CharacterType character)
{
return isASCIIDigit(character) || (toASCIILowerUnchecked(character) >= 'a' && toASCIILowerUnchecked(character) <= 'f');
}
template<typename CharacterType> inline bool isASCIIBinaryDigit(CharacterType character)
{
return character == '0' || character == '1';
}
template<typename CharacterType> inline bool isASCIIOctalDigit(CharacterType character)
{
return character >= '0' && character <= '7';
}
template<typename CharacterType> inline bool isASCIIPrintable(CharacterType character)
{
return character >= ' ' && character <= '~';
}
/*
Statistics from a run of Apple's page load test for callers of isASCIISpace:
character count
--------- -----
non-spaces 689383
20 space 294720
0A \n 89059
09 \t 28320
0D \r 0
0C \f 0
0B \v 0
Because of those, we first check to quickly return false for non-control characters,
then check for space itself to quickly return true for that case, then do the rest.
*/
template<typename CharacterType> inline bool isASCIISpace(CharacterType character)
{
return character <= ' ' && (character == ' ' || (character <= 0xD && character >= 0x9));
}
template<typename CharacterType> inline bool isASCIIUpper(CharacterType character)
{
return character >= 'A' && character <= 'Z';
}
template<typename CharacterType> inline CharacterType toASCIILower(CharacterType character)
{
return character | (isASCIIUpper(character) << 5);
}
template<> inline char toASCIILower(char character)
{
return static_cast<char>(asciiCaseFoldTable[static_cast<uint8_t>(character)]);
}
template<> inline LChar toASCIILower(LChar character)
{
return asciiCaseFoldTable[character];
}
template<typename CharacterType> inline CharacterType toASCIIUpper(CharacterType character)
{
return character & ~(isASCIILower(character) << 5);
}
template<typename CharacterType> inline uint8_t toASCIIHexValue(CharacterType character)
{
ASSERT(isASCIIHexDigit(character));
return character < 'A' ? character - '0' : (character - 'A' + 10) & 0xF;
}
template<typename CharacterType> inline uint8_t toASCIIHexValue(CharacterType firstCharacter, CharacterType secondCharacter)
{
return toASCIIHexValue(firstCharacter) << 4 | toASCIIHexValue(secondCharacter);
}
inline char lowerNibbleToASCIIHexDigit(uint8_t value)
{
uint8_t nibble = value & 0xF;
return nibble + (nibble < 10 ? '0' : 'A' - 10);
}
inline char upperNibbleToASCIIHexDigit(uint8_t value)
{
uint8_t nibble = value >> 4;
return nibble + (nibble < 10 ? '0' : 'A' - 10);
}
inline char lowerNibbleToLowercaseASCIIHexDigit(uint8_t value)
{
uint8_t nibble = value & 0xF;
return nibble + (nibble < 10 ? '0' : 'a' - 10);
}
inline char upperNibbleToLowercaseASCIIHexDigit(uint8_t value)
{
uint8_t nibble = value >> 4;
return nibble + (nibble < 10 ? '0' : 'a' - 10);
}
template<typename CharacterType> inline bool isASCIIAlphaCaselessEqual(CharacterType inputCharacter, char expectedASCIILowercaseLetter)
{
// Name of this argument says this must be a lowercase letter, but it can actually be:
// - a lowercase letter
// - a numeric digit
// - a space
// - punctuation in the range 0x21-0x3F, including "-", "/", and "+"
// It cannot be:
// - an uppercase letter
// - a non-ASCII character
// - other punctuation, such as underscore and backslash
// - a control character such as "\n"
// FIXME: Would be nice to make both the function name and expectedASCIILowercaseLetter argument name clearer.
ASSERT(toASCIILowerUnchecked(expectedASCIILowercaseLetter) == expectedASCIILowercaseLetter);
return LIKELY(toASCIILowerUnchecked(inputCharacter) == expectedASCIILowercaseLetter);
}
template<typename CharacterType> inline bool isASCIIDigitOrPunctuation(CharacterType charCode)
{
return (charCode >= '!' && charCode <= '@') || (charCode >= '[' && charCode <= '`') || (charCode >= '{' && charCode <= '~');
}
}
using WTF::isASCII;
using WTF::isASCIIAlpha;
using WTF::isASCIIAlphaCaselessEqual;
using WTF::isASCIIAlphanumeric;
using WTF::isASCIIBinaryDigit;
using WTF::isASCIIDigit;
using WTF::isASCIIDigitOrPunctuation;
using WTF::isASCIIHexDigit;
using WTF::isASCIILower;
using WTF::isASCIIOctalDigit;
using WTF::isASCIIPrintable;
using WTF::isASCIISpace;
using WTF::isASCIIUpper;
using WTF::lowerNibbleToASCIIHexDigit;
using WTF::lowerNibbleToLowercaseASCIIHexDigit;
using WTF::toASCIIHexValue;
using WTF::toASCIILower;
using WTF::toASCIILowerUnchecked;
using WTF::toASCIIUpper;
using WTF::upperNibbleToASCIIHexDigit;
using WTF::upperNibbleToLowercaseASCIIHexDigit;