1/*
2 * (C) 1999 Lars Knoll (knoll@kde.org)
3 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
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 WTFString_h
23#define WTFString_h
24
25// This file would be called String.h, but that conflicts with <string.h>
26// on systems without case-sensitive file systems.
27
28#include "wtf/HashTableDeletedValueType.h"
29#include "wtf/WTFExport.h"
30#include "wtf/text/ASCIIFastPath.h"
31#include "wtf/text/StringImpl.h"
32#include "wtf/text/StringView.h"
33
34#ifdef __OBJC__
35#include <objc/objc.h>
36#endif
37
38namespace WTF {
39
40class CString;
41struct StringHash;
42
43// Declarations of string operations
44
45WTF_EXPORT int charactersToIntStrict(const LChar*, size_t, bool* ok = 0, int base = 10);
46WTF_EXPORT int charactersToIntStrict(const UChar*, size_t, bool* ok = 0, int base = 10);
47WTF_EXPORT unsigned charactersToUIntStrict(const LChar*, size_t, bool* ok = 0, int base = 10);
48WTF_EXPORT unsigned charactersToUIntStrict(const UChar*, size_t, bool* ok = 0, int base = 10);
49WTF_EXPORT int64_t charactersToInt64Strict(const LChar*, size_t, bool* ok = 0, int base = 10);
50WTF_EXPORT int64_t charactersToInt64Strict(const UChar*, size_t, bool* ok = 0, int base = 10);
51WTF_EXPORT uint64_t charactersToUInt64Strict(const LChar*, size_t, bool* ok = 0, int base = 10);
52WTF_EXPORT uint64_t charactersToUInt64Strict(const UChar*, size_t, bool* ok = 0, int base = 10);
53WTF_EXPORT intptr_t charactersToIntPtrStrict(const LChar*, size_t, bool* ok = 0, int base = 10);
54WTF_EXPORT intptr_t charactersToIntPtrStrict(const UChar*, size_t, bool* ok = 0, int base = 10);
55
56WTF_EXPORT int charactersToInt(const LChar*, size_t, bool* ok = 0); // ignores trailing garbage
57WTF_EXPORT int charactersToInt(const UChar*, size_t, bool* ok = 0); // ignores trailing garbage
58WTF_EXPORT unsigned charactersToUInt(const LChar*, size_t, bool* ok = 0); // ignores trailing garbage
59WTF_EXPORT unsigned charactersToUInt(const UChar*, size_t, bool* ok = 0); // ignores trailing garbage
60WTF_EXPORT int64_t charactersToInt64(const LChar*, size_t, bool* ok = 0); // ignores trailing garbage
61WTF_EXPORT int64_t charactersToInt64(const UChar*, size_t, bool* ok = 0); // ignores trailing garbage
62WTF_EXPORT uint64_t charactersToUInt64(const LChar*, size_t, bool* ok = 0); // ignores trailing garbage
63WTF_EXPORT uint64_t charactersToUInt64(const UChar*, size_t, bool* ok = 0); // ignores trailing garbage
64WTF_EXPORT intptr_t charactersToIntPtr(const LChar*, size_t, bool* ok = 0); // ignores trailing garbage
65WTF_EXPORT intptr_t charactersToIntPtr(const UChar*, size_t, bool* ok = 0); // ignores trailing garbage
66
67// FIXME: Like the strict functions above, these give false for "ok" when there is trailing garbage.
68// Like the non-strict functions above, these return the value when there is trailing garbage.
69// It would be better if these were more consistent with the above functions instead.
70WTF_EXPORT double charactersToDouble(const LChar*, size_t, bool* ok = 0);
71WTF_EXPORT double charactersToDouble(const UChar*, size_t, bool* ok = 0);
72WTF_EXPORT float charactersToFloat(const LChar*, size_t, bool* ok = 0);
73WTF_EXPORT float charactersToFloat(const UChar*, size_t, bool* ok = 0);
74WTF_EXPORT float charactersToFloat(const LChar*, size_t, size_t& parsedLength);
75WTF_EXPORT float charactersToFloat(const UChar*, size_t, size_t& parsedLength);
76
77enum TrailingZerosTruncatingPolicy {
78    KeepTrailingZeros,
79    TruncateTrailingZeros
80};
81
82enum UTF8ConversionMode {
83    LenientUTF8Conversion,
84    StrictUTF8Conversion,
85    StrictUTF8ConversionReplacingUnpairedSurrogatesWithFFFD
86};
87
88template<bool isSpecialCharacter(UChar), typename CharacterType>
89bool isAllSpecialCharacters(const CharacterType*, size_t);
90
91// You can find documentation about this class in this doc:
92// https://docs.google.com/document/d/1kOCUlJdh2WJMJGDf-WoEQhmnjKLaOYRbiHz5TiGJl14/edit?usp=sharing
93class WTF_EXPORT String {
94public:
95    // Construct a null string, distinguishable from an empty string.
96    String() { }
97
98    // Construct a string with UTF-16 data.
99    String(const UChar* characters, unsigned length);
100
101    // Construct a string by copying the contents of a vector.
102    // This method will never create a null string. Vectors with size() == 0
103    // will return the empty string.
104    // NOTE: This is different from String(vector.data(), vector.size())
105    // which will sometimes return a null string when vector.data() is null
106    // which can only occur for vectors without inline capacity.
107    // See: https://bugs.webkit.org/show_bug.cgi?id=109792
108    template<size_t inlineCapacity>
109    explicit String(const Vector<UChar, inlineCapacity>&);
110
111    // Construct a string with UTF-16 data, from a null-terminated source.
112    String(const UChar*);
113
114    // Construct a string with latin1 data.
115    String(const LChar* characters, unsigned length);
116    String(const char* characters, unsigned length);
117
118    // Construct a string with latin1 data, from a null-terminated source.
119    String(const LChar* characters);
120    String(const char* characters);
121
122    // Construct a string referencing an existing StringImpl.
123    String(StringImpl* impl) : m_impl(impl) { }
124    String(PassRefPtr<StringImpl> impl) : m_impl(impl) { }
125
126    void swap(String& o) { m_impl.swap(o.m_impl); }
127
128    template<typename CharType>
129    static String adopt(StringBuffer<CharType>& buffer)
130    {
131        if (!buffer.length())
132            return StringImpl::empty();
133        return String(buffer.release());
134    }
135
136    bool isNull() const { return !m_impl; }
137    bool isEmpty() const { return !m_impl || !m_impl->length(); }
138
139    StringImpl* impl() const { return m_impl.get(); }
140    PassRefPtr<StringImpl> releaseImpl() { return m_impl.release(); }
141
142    unsigned length() const
143    {
144        if (!m_impl)
145            return 0;
146        return m_impl->length();
147    }
148
149    const LChar* characters8() const
150    {
151        if (!m_impl)
152            return 0;
153        ASSERT(m_impl->is8Bit());
154        return m_impl->characters8();
155    }
156
157    const UChar* characters16() const
158    {
159        if (!m_impl)
160            return 0;
161        ASSERT(!m_impl->is8Bit());
162        return m_impl->characters16();
163    }
164
165    // Return characters8() or characters16() depending on CharacterType.
166    template <typename CharacterType>
167    inline const CharacterType* getCharacters() const;
168
169    bool is8Bit() const { return m_impl->is8Bit(); }
170
171    unsigned sizeInBytes() const
172    {
173        if (!m_impl)
174            return 0;
175        return m_impl->length() * (is8Bit() ? sizeof(LChar) : sizeof(UChar));
176    }
177
178    CString ascii() const;
179    CString latin1() const;
180    CString utf8(UTF8ConversionMode = LenientUTF8Conversion) const;
181
182    UChar operator[](unsigned index) const
183    {
184        if (!m_impl || index >= m_impl->length())
185            return 0;
186        return (*m_impl)[index];
187    }
188
189    static String number(int);
190    static String number(unsigned);
191    static String number(long);
192    static String number(unsigned long);
193    static String number(long long);
194    static String number(unsigned long long);
195
196    static String number(double, unsigned precision = 6, TrailingZerosTruncatingPolicy = TruncateTrailingZeros);
197
198    // Number to String conversion following the ECMAScript definition.
199    static String numberToStringECMAScript(double);
200    static String numberToStringFixedWidth(double, unsigned decimalPlaces);
201
202    // Find a single character or string, also with match function & latin1 forms.
203    size_t find(UChar c, unsigned start = 0) const
204        { return m_impl ? m_impl->find(c, start) : kNotFound; }
205
206    size_t find(const String& str) const
207        { return m_impl ? m_impl->find(str.impl()) : kNotFound; }
208    size_t find(const String& str, unsigned start) const
209        { return m_impl ? m_impl->find(str.impl(), start) : kNotFound; }
210
211    size_t find(CharacterMatchFunctionPtr matchFunction, unsigned start = 0) const
212        { return m_impl ? m_impl->find(matchFunction, start) : kNotFound; }
213    size_t find(const LChar* str, unsigned start = 0) const
214        { return m_impl ? m_impl->find(str, start) : kNotFound; }
215
216    size_t findNextLineStart(unsigned start = 0) const
217        { return m_impl ? m_impl->findNextLineStart(start) : kNotFound; }
218
219    // Find the last instance of a single character or string.
220    size_t reverseFind(UChar c, unsigned start = UINT_MAX) const
221        { return m_impl ? m_impl->reverseFind(c, start) : kNotFound; }
222    size_t reverseFind(const String& str, unsigned start = UINT_MAX) const
223        { return m_impl ? m_impl->reverseFind(str.impl(), start) : kNotFound; }
224
225    // Case insensitive string matching.
226    size_t findIgnoringCase(const LChar* str, unsigned start = 0) const
227        { return m_impl ? m_impl->findIgnoringCase(str, start) : kNotFound; }
228    size_t findIgnoringCase(const String& str, unsigned start = 0) const
229        { return m_impl ? m_impl->findIgnoringCase(str.impl(), start) : kNotFound; }
230    size_t reverseFindIgnoringCase(const String& str, unsigned start = UINT_MAX) const
231        { return m_impl ? m_impl->reverseFindIgnoringCase(str.impl(), start) : kNotFound; }
232
233    // Wrappers for find & reverseFind adding dynamic sensitivity check.
234    size_t find(const LChar* str, unsigned start, bool caseSensitive) const
235        { return caseSensitive ? find(str, start) : findIgnoringCase(str, start); }
236    size_t find(const String& str, unsigned start, bool caseSensitive) const
237        { return caseSensitive ? find(str, start) : findIgnoringCase(str, start); }
238    size_t reverseFind(const String& str, unsigned start, bool caseSensitive) const
239        { return caseSensitive ? reverseFind(str, start) : reverseFindIgnoringCase(str, start); }
240
241    Vector<UChar> charactersWithNullTermination() const;
242    unsigned copyTo(UChar* buffer, unsigned pos, unsigned maxLength) const;
243
244    template<size_t inlineCapacity>
245    void appendTo(Vector<UChar, inlineCapacity>&, unsigned pos = 0, unsigned len = UINT_MAX) const;
246
247    template<typename BufferType>
248    void appendTo(BufferType&, unsigned pos = 0, unsigned len = UINT_MAX) const;
249
250    template<size_t inlineCapacity>
251    void prependTo(Vector<UChar, inlineCapacity>&, unsigned pos = 0, unsigned len = UINT_MAX) const;
252
253    UChar32 characterStartingAt(unsigned) const;
254
255    bool contains(UChar c) const { return find(c) != kNotFound; }
256    bool contains(const LChar* str, bool caseSensitive = true) const { return find(str, 0, caseSensitive) != kNotFound; }
257    bool contains(const String& str, bool caseSensitive = true) const { return find(str, 0, caseSensitive) != kNotFound; }
258
259    bool startsWith(const String& s, bool caseSensitive = true) const
260        { return m_impl ? m_impl->startsWith(s.impl(), caseSensitive) : s.isEmpty(); }
261    bool startsWith(UChar character) const
262        { return m_impl ? m_impl->startsWith(character) : false; }
263    template<unsigned matchLength>
264    bool startsWith(const char (&prefix)[matchLength], bool caseSensitive = true) const
265        { return m_impl ? m_impl->startsWith<matchLength>(prefix, caseSensitive) : !matchLength; }
266
267    bool endsWith(const String& s, bool caseSensitive = true) const
268        { return m_impl ? m_impl->endsWith(s.impl(), caseSensitive) : s.isEmpty(); }
269    bool endsWith(UChar character) const
270        { return m_impl ? m_impl->endsWith(character) : false; }
271    template<unsigned matchLength>
272    bool endsWith(const char (&prefix)[matchLength], bool caseSensitive = true) const
273        { return m_impl ? m_impl->endsWith<matchLength>(prefix, caseSensitive) : !matchLength; }
274
275    void append(const String&);
276    void append(LChar);
277    void append(char c) { append(static_cast<LChar>(c)); }
278    void append(UChar);
279    void append(const LChar*, unsigned length);
280    void append(const char* charactersToAppend, unsigned length) { append(reinterpret_cast<const LChar*>(charactersToAppend), length); }
281    void append(const UChar*, unsigned length);
282    void insert(const String&, unsigned pos);
283    void insert(const LChar*, unsigned length, unsigned pos);
284    void insert(const UChar*, unsigned length, unsigned pos);
285
286    String& replace(UChar a, UChar b) { if (m_impl) m_impl = m_impl->replace(a, b); return *this; }
287    String& replace(UChar a, const String& b) { if (m_impl) m_impl = m_impl->replace(a, b.impl()); return *this; }
288    String& replace(const String& a, const String& b) { if (m_impl) m_impl = m_impl->replace(a.impl(), b.impl()); return *this; }
289    String& replace(unsigned index, unsigned len, const String& b) { if (m_impl) m_impl = m_impl->replace(index, len, b.impl()); return *this; }
290
291    template<unsigned charactersCount>
292    ALWAYS_INLINE String& replaceWithLiteral(UChar a, const char (&characters)[charactersCount])
293    {
294        if (m_impl)
295            m_impl = m_impl->replace(a, characters, charactersCount - 1);
296
297        return *this;
298    }
299
300    void fill(UChar c) { if (m_impl) m_impl = m_impl->fill(c); }
301
302    void ensure16Bit();
303
304    void truncate(unsigned len);
305    void remove(unsigned pos, int len = 1);
306
307    String substring(unsigned pos, unsigned len = UINT_MAX) const;
308    String left(unsigned len) const { return substring(0, len); }
309    String right(unsigned len) const { return substring(length() - len, len); }
310
311    StringView createView() const { return StringView(impl()); }
312    StringView createView(unsigned offset, unsigned length) const { return StringView(impl(), offset, length); }
313
314    // Returns a lowercase/uppercase version of the string
315    String lower() const;
316    String upper() const;
317
318    String lower(const AtomicString& localeIdentifier) const;
319    String upper(const AtomicString& localeIdentifier) const;
320
321    String stripWhiteSpace() const;
322    String stripWhiteSpace(IsWhiteSpaceFunctionPtr) const;
323    String simplifyWhiteSpace(StripBehavior stripBehavior = StripExtraWhiteSpace) const;
324    String simplifyWhiteSpace(IsWhiteSpaceFunctionPtr, StripBehavior stripBehavior = StripExtraWhiteSpace) const;
325
326    String removeCharacters(CharacterMatchFunctionPtr) const;
327    template<bool isSpecialCharacter(UChar)> bool isAllSpecialCharacters() const;
328
329    // Return the string with case folded for case insensitive comparison.
330    String foldCase() const;
331
332    static String format(const char *, ...) WTF_ATTRIBUTE_PRINTF(1, 2);
333
334    // Returns an uninitialized string. The characters needs to be written
335    // into the buffer returned in data before the returned string is used.
336    // Failure to do this will have unpredictable results.
337    static String createUninitialized(unsigned length, UChar*& data) { return StringImpl::createUninitialized(length, data); }
338    static String createUninitialized(unsigned length, LChar*& data) { return StringImpl::createUninitialized(length, data); }
339
340    void split(const String& separator, bool allowEmptyEntries, Vector<String>& result) const;
341    void split(const String& separator, Vector<String>& result) const
342    {
343        split(separator, false, result);
344    }
345    void split(UChar separator, bool allowEmptyEntries, Vector<String>& result) const;
346    void split(UChar separator, Vector<String>& result) const
347    {
348        split(separator, false, result);
349    }
350
351    int toIntStrict(bool* ok = 0, int base = 10) const;
352    unsigned toUIntStrict(bool* ok = 0, int base = 10) const;
353    int64_t toInt64Strict(bool* ok = 0, int base = 10) const;
354    uint64_t toUInt64Strict(bool* ok = 0, int base = 10) const;
355    intptr_t toIntPtrStrict(bool* ok = 0, int base = 10) const;
356
357    int toInt(bool* ok = 0) const;
358    unsigned toUInt(bool* ok = 0) const;
359    int64_t toInt64(bool* ok = 0) const;
360    uint64_t toUInt64(bool* ok = 0) const;
361    intptr_t toIntPtr(bool* ok = 0) const;
362
363    // FIXME: Like the strict functions above, these give false for "ok" when there is trailing garbage.
364    // Like the non-strict functions above, these return the value when there is trailing garbage.
365    // It would be better if these were more consistent with the above functions instead.
366    double toDouble(bool* ok = 0) const;
367    float toFloat(bool* ok = 0) const;
368
369    bool percentage(int& percentage) const;
370
371    String isolatedCopy() const;
372    bool isSafeToSendToAnotherThread() const;
373
374#if USE(CF)
375    String(CFStringRef);
376    RetainPtr<CFStringRef> createCFString() const;
377#endif
378
379#ifdef __OBJC__
380    String(NSString*);
381
382    // This conversion maps NULL to "", which loses the meaning of NULL, but we
383    // need this mapping because AppKit crashes when passed nil NSStrings.
384    operator NSString*() const { if (!m_impl) return @""; return *m_impl; }
385#endif
386
387    static String make8BitFrom16BitSource(const UChar*, size_t);
388    template<size_t inlineCapacity>
389    static String make8BitFrom16BitSource(const Vector<UChar, inlineCapacity>& buffer)
390    {
391        return make8BitFrom16BitSource(buffer.data(), buffer.size());
392    }
393
394    static String make16BitFrom8BitSource(const LChar*, size_t);
395
396    // String::fromUTF8 will return a null string if
397    // the input data contains invalid UTF-8 sequences.
398    static String fromUTF8(const LChar*, size_t);
399    static String fromUTF8(const LChar*);
400    static String fromUTF8(const char* s, size_t length) { return fromUTF8(reinterpret_cast<const LChar*>(s), length); };
401    static String fromUTF8(const char* s) { return fromUTF8(reinterpret_cast<const LChar*>(s)); };
402    static String fromUTF8(const CString&);
403
404    // Tries to convert the passed in string to UTF-8, but will fall back to Latin-1 if the string is not valid UTF-8.
405    static String fromUTF8WithLatin1Fallback(const LChar*, size_t);
406    static String fromUTF8WithLatin1Fallback(const char* s, size_t length) { return fromUTF8WithLatin1Fallback(reinterpret_cast<const LChar*>(s), length); };
407
408    bool containsOnlyASCII() const;
409    bool containsOnlyLatin1() const;
410    bool containsOnlyWhitespace() const { return !m_impl || m_impl->containsOnlyWhitespace(); }
411
412    // Hash table deleted values, which are only constructed and never copied or destroyed.
413    String(WTF::HashTableDeletedValueType) : m_impl(WTF::HashTableDeletedValue) { }
414    bool isHashTableDeletedValue() const { return m_impl.isHashTableDeletedValue(); }
415
416#ifndef NDEBUG
417    void show() const;
418#endif
419
420    // Workaround for a compiler bug. Use operator[] instead.
421    UChar characterAt(unsigned index) const
422    {
423        if (!m_impl || index >= m_impl->length())
424            return 0;
425        return (*m_impl)[index];
426    }
427
428private:
429    typedef struct ImplicitConversionFromWTFStringToBoolDisallowed* (String::*UnspecifiedBoolType);
430    operator UnspecifiedBoolType() const;
431
432    template <typename CharacterType>
433    void removeInternal(const CharacterType*, unsigned, int);
434
435    template <typename CharacterType>
436    void appendInternal(CharacterType);
437
438    RefPtr<StringImpl> m_impl;
439};
440
441inline bool operator==(const String& a, const String& b) { return equal(a.impl(), b.impl()); }
442inline bool operator==(const String& a, const LChar* b) { return equal(a.impl(), b); }
443inline bool operator==(const String& a, const char* b) { return equal(a.impl(), reinterpret_cast<const LChar*>(b)); }
444inline bool operator==(const LChar* a, const String& b) { return equal(a, b.impl()); }
445inline bool operator==(const char* a, const String& b) { return equal(reinterpret_cast<const LChar*>(a), b.impl()); }
446template<size_t inlineCapacity>
447inline bool operator==(const Vector<char, inlineCapacity>& a, const String& b) { return equal(b.impl(), a.data(), a.size()); }
448template<size_t inlineCapacity>
449inline bool operator==(const String& a, const Vector<char, inlineCapacity>& b) { return b == a; }
450
451
452inline bool operator!=(const String& a, const String& b) { return !equal(a.impl(), b.impl()); }
453inline bool operator!=(const String& a, const LChar* b) { return !equal(a.impl(), b); }
454inline bool operator!=(const String& a, const char* b) { return !equal(a.impl(), reinterpret_cast<const LChar*>(b)); }
455inline bool operator!=(const LChar* a, const String& b) { return !equal(a, b.impl()); }
456inline bool operator!=(const char* a, const String& b) { return !equal(reinterpret_cast<const LChar*>(a), b.impl()); }
457template<size_t inlineCapacity>
458inline bool operator!=(const Vector<char, inlineCapacity>& a, const String& b) { return !(a == b); }
459template<size_t inlineCapacity>
460inline bool operator!=(const String& a, const Vector<char, inlineCapacity>& b) { return b != a; }
461
462inline bool equalIgnoringCase(const String& a, const String& b) { return equalIgnoringCase(a.impl(), b.impl()); }
463inline bool equalIgnoringCase(const String& a, const LChar* b) { return equalIgnoringCase(a.impl(), b); }
464inline bool equalIgnoringCase(const String& a, const char* b) { return equalIgnoringCase(a.impl(), reinterpret_cast<const LChar*>(b)); }
465inline bool equalIgnoringCase(const LChar* a, const String& b) { return equalIgnoringCase(a, b.impl()); }
466inline bool equalIgnoringCase(const char* a, const String& b) { return equalIgnoringCase(reinterpret_cast<const LChar*>(a), b.impl()); }
467
468inline bool equalPossiblyIgnoringCase(const String& a, const String& b, bool ignoreCase)
469{
470    return ignoreCase ? equalIgnoringCase(a, b) : (a == b);
471}
472
473inline bool equalIgnoringNullity(const String& a, const String& b) { return equalIgnoringNullity(a.impl(), b.impl()); }
474
475template<size_t inlineCapacity>
476inline bool equalIgnoringNullity(const Vector<UChar, inlineCapacity>& a, const String& b) { return equalIgnoringNullity(a, b.impl()); }
477
478inline bool operator!(const String& str) { return str.isNull(); }
479
480inline void swap(String& a, String& b) { a.swap(b); }
481
482// Definitions of string operations
483
484template<size_t inlineCapacity>
485String::String(const Vector<UChar, inlineCapacity>& vector)
486    : m_impl(vector.size() ? StringImpl::create(vector.data(), vector.size()) : StringImpl::empty())
487{
488}
489
490template<>
491inline const LChar* String::getCharacters<LChar>() const
492{
493    ASSERT(is8Bit());
494    return characters8();
495}
496
497template<>
498inline const UChar* String::getCharacters<UChar>() const
499{
500    ASSERT(!is8Bit());
501    return characters16();
502}
503
504inline bool String::containsOnlyLatin1() const
505{
506    if (isEmpty())
507        return true;
508
509    if (is8Bit())
510        return true;
511
512    const UChar* characters = characters16();
513    UChar ored = 0;
514    for (size_t i = 0; i < m_impl->length(); ++i)
515        ored |= characters[i];
516    return !(ored & 0xFF00);
517}
518
519
520#ifdef __OBJC__
521// This is for situations in WebKit where the long standing behavior has been
522// "nil if empty", so we try to maintain longstanding behavior for the sake of
523// entrenched clients
524inline NSString* nsStringNilIfEmpty(const String& str) {  return str.isEmpty() ? nil : (NSString*)str; }
525#endif
526
527inline bool String::containsOnlyASCII() const
528{
529    if (isEmpty())
530        return true;
531
532    if (is8Bit())
533        return charactersAreAllASCII(characters8(), m_impl->length());
534
535    return charactersAreAllASCII(characters16(), m_impl->length());
536}
537
538WTF_EXPORT int codePointCompare(const String&, const String&);
539
540inline bool codePointCompareLessThan(const String& a, const String& b)
541{
542    return codePointCompare(a.impl(), b.impl()) < 0;
543}
544
545template<size_t inlineCapacity>
546inline void append(Vector<UChar, inlineCapacity>& vector, const String& string)
547{
548    unsigned length = string.length();
549    if (!length)
550        return;
551    if (string.is8Bit()) {
552        const LChar* characters8 = string.characters8();
553        vector.reserveCapacity(vector.size() + length);
554        for (size_t i = 0; i < length; ++i)
555            vector.uncheckedAppend(characters8[i]);
556    } else {
557        vector.append(string.characters16(), length);
558    }
559}
560
561template<typename CharacterType>
562inline void appendNumber(Vector<CharacterType>& vector, unsigned char number)
563{
564    int numberLength = number > 99 ? 3 : (number > 9 ? 2 : 1);
565    size_t vectorSize = vector.size();
566    vector.grow(vectorSize + numberLength);
567
568    switch (numberLength) {
569    case 3:
570        vector[vectorSize + 2] = number % 10 + '0';
571        number /= 10;
572
573    case 2:
574        vector[vectorSize + 1] = number % 10 + '0';
575        number /= 10;
576
577    case 1:
578        vector[vectorSize] = number % 10 + '0';
579    }
580}
581
582template<bool isSpecialCharacter(UChar), typename CharacterType>
583inline bool isAllSpecialCharacters(const CharacterType* characters, size_t length)
584{
585    for (size_t i = 0; i < length; ++i) {
586        if (!isSpecialCharacter(characters[i]))
587            return false;
588    }
589    return true;
590}
591
592template<bool isSpecialCharacter(UChar)>
593inline bool String::isAllSpecialCharacters() const
594{
595    size_t len = length();
596
597    if (!len)
598        return true;
599
600    if (is8Bit())
601        return WTF::isAllSpecialCharacters<isSpecialCharacter, LChar>(characters8(), len);
602    return WTF::isAllSpecialCharacters<isSpecialCharacter, UChar>(characters16(), len);
603}
604
605template<size_t inlineCapacity>
606inline void String::appendTo(Vector<UChar, inlineCapacity>& result, unsigned pos, unsigned len) const
607{
608    unsigned numberOfCharactersToCopy = std::min(len, length() - pos);
609    if (!numberOfCharactersToCopy)
610        return;
611    result.reserveCapacity(result.size() + numberOfCharactersToCopy);
612    if (is8Bit()) {
613        const LChar* characters8 = m_impl->characters8();
614        for (size_t i = 0; i < numberOfCharactersToCopy; ++i)
615            result.uncheckedAppend(characters8[pos + i]);
616    } else {
617        const UChar* characters16 = m_impl->characters16();
618        result.append(characters16 + pos, numberOfCharactersToCopy);
619    }
620}
621
622template<typename BufferType>
623inline void String::appendTo(BufferType& result, unsigned pos, unsigned len) const
624{
625    unsigned numberOfCharactersToCopy = std::min(len, length() - pos);
626    if (!numberOfCharactersToCopy)
627        return;
628    if (is8Bit())
629        result.append(m_impl->characters8() + pos, numberOfCharactersToCopy);
630    else
631        result.append(m_impl->characters16() + pos, numberOfCharactersToCopy);
632}
633
634template<size_t inlineCapacity>
635inline void String::prependTo(Vector<UChar, inlineCapacity>& result, unsigned pos, unsigned len) const
636{
637    unsigned numberOfCharactersToCopy = std::min(len, length() - pos);
638    if (!numberOfCharactersToCopy)
639        return;
640    if (is8Bit()) {
641        size_t oldSize = result.size();
642        result.resize(oldSize + numberOfCharactersToCopy);
643        memmove(result.data() + numberOfCharactersToCopy, result.data(), oldSize * sizeof(UChar));
644        StringImpl::copyChars(result.data(), m_impl->characters8() + pos, numberOfCharactersToCopy);
645    } else {
646        result.prepend(m_impl->characters16() + pos, numberOfCharactersToCopy);
647    }
648}
649
650// StringHash is the default hash for String
651template<typename T> struct DefaultHash;
652template<> struct DefaultHash<String> {
653    typedef StringHash Hash;
654};
655
656// Shared global empty string.
657WTF_EXPORT const String& emptyString();
658WTF_EXPORT const String& emptyString16Bit();
659WTF_EXPORT extern const String& xmlnsWithColon;
660
661} // namespace WTF
662
663WTF_ALLOW_MOVE_AND_INIT_WITH_MEM_FUNCTIONS(String);
664
665using WTF::CString;
666using WTF::KeepTrailingZeros;
667using WTF::StrictUTF8Conversion;
668using WTF::StrictUTF8ConversionReplacingUnpairedSurrogatesWithFFFD;
669using WTF::String;
670using WTF::emptyString;
671using WTF::emptyString16Bit;
672using WTF::append;
673using WTF::appendNumber;
674using WTF::charactersAreAllASCII;
675using WTF::charactersToIntStrict;
676using WTF::charactersToUIntStrict;
677using WTF::charactersToInt64Strict;
678using WTF::charactersToUInt64Strict;
679using WTF::charactersToIntPtrStrict;
680using WTF::charactersToInt;
681using WTF::charactersToUInt;
682using WTF::charactersToInt64;
683using WTF::charactersToUInt64;
684using WTF::charactersToIntPtr;
685using WTF::charactersToDouble;
686using WTF::charactersToFloat;
687using WTF::equal;
688using WTF::equalIgnoringCase;
689using WTF::find;
690using WTF::isAllSpecialCharacters;
691using WTF::isSpaceOrNewline;
692using WTF::reverseFind;
693
694#include "wtf/text/AtomicString.h"
695#endif // WTFString_h
696