1/*
2 * Copyright (C) 2007-2019 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
16 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
17 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
18 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
19 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
20 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
22 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25#pragma once
26
27#include <wtf/Assertions.h>
28#include <wtf/text/LChar.h>
29
30// The behavior of many of the functions in the <ctype.h> header is dependent
31// on the current locale. But in the WebKit project, all uses of those functions
32// are in code processing something that's not locale-specific. These equivalents
33// for some of the <ctype.h> functions are named more explicitly, not dependent
34// on the C library locale, and we should also optimize them as needed.
35
36// All functions return false or leave the character unchanged if passed a character
37// that is outside the range 0-7F. So they can be used on Unicode strings or
38// characters if the intent is to do processing only if the character is ASCII.
39
40namespace WTF {
41
42template<typename CharacterType> bool isASCII(CharacterType);
43template<typename CharacterType> bool isASCIIAlpha(CharacterType);
44template<typename CharacterType> bool isASCIIAlphanumeric(CharacterType);
45template<typename CharacterType> bool isASCIIBinaryDigit(CharacterType);
46template<typename CharacterType> bool isASCIIDigit(CharacterType);
47template<typename CharacterType> bool isASCIIHexDigit(CharacterType);
48template<typename CharacterType> bool isASCIILower(CharacterType);
49template<typename CharacterType> bool isASCIIOctalDigit(CharacterType);
50template<typename CharacterType> bool isASCIIPrintable(CharacterType);
51template<typename CharacterType> bool isASCIISpace(CharacterType);
52template<typename CharacterType> bool isASCIIUpper(CharacterType);
53
54template<typename CharacterType> CharacterType toASCIILower(CharacterType);
55template<typename CharacterType> CharacterType toASCIIUpper(CharacterType);
56
57template<typename CharacterType> uint8_t toASCIIHexValue(CharacterType);
58template<typename CharacterType> uint8_t toASCIIHexValue(CharacterType firstCharacter, CharacterType secondCharacter);
59
60char lowerNibbleToASCIIHexDigit(uint8_t);
61char upperNibbleToASCIIHexDigit(uint8_t);
62char lowerNibbleToLowercaseASCIIHexDigit(uint8_t);
63char upperNibbleToLowercaseASCIIHexDigit(uint8_t);
64
65template<typename CharacterType> bool isASCIIAlphaCaselessEqual(CharacterType, char expectedASCIILowercaseLetter);
66
67// The toASCIILowerUnchecked function can be used for comparing any input character
68// to a lowercase English character. The isASCIIAlphaCaselessEqual function should
69// be used for regular comparison of ASCII alpha characters, but switch statements
70// in the CSS tokenizer, for example, instead make direct use toASCIILowerUnchecked.
71template<typename CharacterType> CharacterType toASCIILowerUnchecked(CharacterType);
72
73extern WTF_EXPORT_PRIVATE const unsigned char asciiCaseFoldTable[256];
74
75template<typename CharacterType> inline bool isASCII(CharacterType character)
76{
77 return !(character & ~0x7F);
78}
79
80template<typename CharacterType> inline bool isASCIILower(CharacterType character)
81{
82 return character >= 'a' && character <= 'z';
83}
84
85template<typename CharacterType> inline CharacterType toASCIILowerUnchecked(CharacterType character)
86{
87 // This function can be used for comparing any input character
88 // to a lowercase English character. The isASCIIAlphaCaselessEqual
89 // below should be used for regular comparison of ASCII alpha
90 // characters, but switch statements in CSS tokenizer instead make
91 // direct use of this function.
92 return character | 0x20;
93}
94
95template<typename CharacterType> inline bool isASCIIAlpha(CharacterType character)
96{
97 return isASCIILower(toASCIILowerUnchecked(character));
98}
99
100template<typename CharacterType> inline bool isASCIIDigit(CharacterType character)
101{
102 return character >= '0' && character <= '9';
103}
104
105template<typename CharacterType> inline bool isASCIIAlphanumeric(CharacterType character)
106{
107 return isASCIIDigit(character) || isASCIIAlpha(character);
108}
109
110template<typename CharacterType> inline bool isASCIIHexDigit(CharacterType character)
111{
112 return isASCIIDigit(character) || (toASCIILowerUnchecked(character) >= 'a' && toASCIILowerUnchecked(character) <= 'f');
113}
114
115template<typename CharacterType> inline bool isASCIIBinaryDigit(CharacterType character)
116{
117 return character == '0' || character == '1';
118}
119
120template<typename CharacterType> inline bool isASCIIOctalDigit(CharacterType character)
121{
122 return character >= '0' && character <= '7';
123}
124
125template<typename CharacterType> inline bool isASCIIPrintable(CharacterType character)
126{
127 return character >= ' ' && character <= '~';
128}
129
130/*
131 Statistics from a run of Apple's page load test for callers of isASCIISpace:
132
133 character count
134 --------- -----
135 non-spaces 689383
136 20 space 294720
137 0A \n 89059
138 09 \t 28320
139 0D \r 0
140 0C \f 0
141 0B \v 0
142
143 Because of those, we first check to quickly return false for non-control characters,
144 then check for space itself to quickly return true for that case, then do the rest.
145*/
146template<typename CharacterType> inline bool isASCIISpace(CharacterType character)
147{
148 return character <= ' ' && (character == ' ' || (character <= 0xD && character >= 0x9));
149}
150
151template<typename CharacterType> inline bool isASCIIUpper(CharacterType character)
152{
153 return character >= 'A' && character <= 'Z';
154}
155
156template<typename CharacterType> inline CharacterType toASCIILower(CharacterType character)
157{
158 return character | (isASCIIUpper(character) << 5);
159}
160
161template<> inline char toASCIILower(char character)
162{
163 return static_cast<char>(asciiCaseFoldTable[static_cast<uint8_t>(character)]);
164}
165
166template<> inline LChar toASCIILower(LChar character)
167{
168 return asciiCaseFoldTable[character];
169}
170
171template<typename CharacterType> inline CharacterType toASCIIUpper(CharacterType character)
172{
173 return character & ~(isASCIILower(character) << 5);
174}
175
176template<typename CharacterType> inline uint8_t toASCIIHexValue(CharacterType character)
177{
178 ASSERT(isASCIIHexDigit(character));
179 return character < 'A' ? character - '0' : (character - 'A' + 10) & 0xF;
180}
181
182template<typename CharacterType> inline uint8_t toASCIIHexValue(CharacterType firstCharacter, CharacterType secondCharacter)
183{
184 return toASCIIHexValue(firstCharacter) << 4 | toASCIIHexValue(secondCharacter);
185}
186
187inline char lowerNibbleToASCIIHexDigit(uint8_t value)
188{
189 uint8_t nibble = value & 0xF;
190 return nibble + (nibble < 10 ? '0' : 'A' - 10);
191}
192
193inline char upperNibbleToASCIIHexDigit(uint8_t value)
194{
195 uint8_t nibble = value >> 4;
196 return nibble + (nibble < 10 ? '0' : 'A' - 10);
197}
198
199inline char lowerNibbleToLowercaseASCIIHexDigit(uint8_t value)
200{
201 uint8_t nibble = value & 0xF;
202 return nibble + (nibble < 10 ? '0' : 'a' - 10);
203}
204
205inline char upperNibbleToLowercaseASCIIHexDigit(uint8_t value)
206{
207 uint8_t nibble = value >> 4;
208 return nibble + (nibble < 10 ? '0' : 'a' - 10);
209}
210
211template<typename CharacterType> inline bool isASCIIAlphaCaselessEqual(CharacterType inputCharacter, char expectedASCIILowercaseLetter)
212{
213 // Name of this argument says this must be a lowercase letter, but it can actually be:
214 // - a lowercase letter
215 // - a numeric digit
216 // - a space
217 // - punctuation in the range 0x21-0x3F, including "-", "/", and "+"
218 // It cannot be:
219 // - an uppercase letter
220 // - a non-ASCII character
221 // - other punctuation, such as underscore and backslash
222 // - a control character such as "\n"
223 // FIXME: Would be nice to make both the function name and expectedASCIILowercaseLetter argument name clearer.
224 ASSERT(toASCIILowerUnchecked(expectedASCIILowercaseLetter) == expectedASCIILowercaseLetter);
225 return LIKELY(toASCIILowerUnchecked(inputCharacter) == expectedASCIILowercaseLetter);
226}
227
228template<typename CharacterType> inline bool isASCIIDigitOrPunctuation(CharacterType charCode)
229{
230 return (charCode >= '!' && charCode <= '@') || (charCode >= '[' && charCode <= '`') || (charCode >= '{' && charCode <= '~');
231}
232
233}
234
235using WTF::isASCII;
236using WTF::isASCIIAlpha;
237using WTF::isASCIIAlphaCaselessEqual;
238using WTF::isASCIIAlphanumeric;
239using WTF::isASCIIBinaryDigit;
240using WTF::isASCIIDigit;
241using WTF::isASCIIDigitOrPunctuation;
242using WTF::isASCIIHexDigit;
243using WTF::isASCIILower;
244using WTF::isASCIIOctalDigit;
245using WTF::isASCIIPrintable;
246using WTF::isASCIISpace;
247using WTF::isASCIIUpper;
248using WTF::lowerNibbleToASCIIHexDigit;
249using WTF::lowerNibbleToLowercaseASCIIHexDigit;
250using WTF::toASCIIHexValue;
251using WTF::toASCIILower;
252using WTF::toASCIILowerUnchecked;
253using WTF::toASCIIUpper;
254using WTF::upperNibbleToASCIIHexDigit;
255using WTF::upperNibbleToLowercaseASCIIHexDigit;
256