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/*
* Copyright (C) 2012-2016 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. ``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
* 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 <stdint.h>
#include <unicode/utypes.h>
namespace JSC { namespace Yarr {
// This set of data provides information for each UCS2 code point as to the set of code points
// that it should match under the ES6 case insensitive RegExp matching rules, specified in 21.2.2.8.2.
// The non-Unicode tables are autogenerated using YarrCanonicalize.js into YarrCanonicalize.cpp.
// The Unicode tables are autogenerated using the python script generateYarrCanonicalizeUnicode
// which creates YarrCanonicalizeUnicode.cpp.
enum UCS2CanonicalizationType {
CanonicalizeUnique, // No canonically equal values, e.g. 0x0.
CanonicalizeSet, // Value indicates a set in characterSetInfo.
CanonicalizeRangeLo, // Value is positive delta to pair, E.g. 0x41 has value 0x20, -> 0x61.
CanonicalizeRangeHi, // Value is positive delta to pair, E.g. 0x61 has value 0x20, -> 0x41.
CanonicalizeAlternatingAligned, // Aligned consequtive pair, e.g. 0x1f4,0x1f5.
CanonicalizeAlternatingUnaligned, // Unaligned consequtive pair, e.g. 0x241,0x242.
};
struct CanonicalizationRange {
UChar32 begin;
UChar32 end;
UChar32 value;
UCS2CanonicalizationType type;
};
extern const size_t UCS2_CANONICALIZATION_RANGES;
extern const UChar32* const ucs2CharacterSetInfo[];
extern const CanonicalizationRange ucs2RangeInfo[];
extern const uint16_t canonicalTableLChar[256];
extern const size_t UNICODE_CANONICALIZATION_RANGES;
extern const UChar32* const unicodeCharacterSetInfo[];
extern const CanonicalizationRange unicodeRangeInfo[];
enum class CanonicalMode { UCS2, Unicode };
inline const UChar32* canonicalCharacterSetInfo(unsigned index, CanonicalMode canonicalMode)
{
const UChar32* const* rangeInfo = canonicalMode == CanonicalMode::UCS2 ? ucs2CharacterSetInfo : unicodeCharacterSetInfo;
return rangeInfo[index];
}
// This searches in log2 time over ~400-600 entries, so should typically result in 9 compares.
inline const CanonicalizationRange* canonicalRangeInfoFor(UChar32 ch, CanonicalMode canonicalMode = CanonicalMode::UCS2)
{
const CanonicalizationRange* info = canonicalMode == CanonicalMode::UCS2 ? ucs2RangeInfo : unicodeRangeInfo;
size_t entries = canonicalMode == CanonicalMode::UCS2 ? UCS2_CANONICALIZATION_RANGES : UNICODE_CANONICALIZATION_RANGES;
while (true) {
size_t candidate = entries >> 1;
const CanonicalizationRange* candidateInfo = info + candidate;
if (ch < candidateInfo->begin)
entries = candidate;
else if (ch <= candidateInfo->end)
return candidateInfo;
else {
info = candidateInfo + 1;
entries -= (candidate + 1);
}
}
}
// Should only be called for characters that have one canonically matching value.
inline UChar32 getCanonicalPair(const CanonicalizationRange* info, UChar32 ch)
{
ASSERT(ch >= info->begin && ch <= info->end);
switch (info->type) {
case CanonicalizeRangeLo:
return ch + info->value;
case CanonicalizeRangeHi:
return ch - info->value;
case CanonicalizeAlternatingAligned:
return ch ^ 1;
case CanonicalizeAlternatingUnaligned:
return ((ch - 1) ^ 1) + 1;
default:
RELEASE_ASSERT_NOT_REACHED();
}
RELEASE_ASSERT_NOT_REACHED();
return 0;
}
// Returns true if no other UCS2 codepoint can match this value.
inline bool isCanonicallyUnique(UChar32 ch, CanonicalMode canonicalMode = CanonicalMode::UCS2)
{
return canonicalRangeInfoFor(ch, canonicalMode)->type == CanonicalizeUnique;
}
// Returns true if values are equal, under the canonicalization rules.
inline bool areCanonicallyEquivalent(UChar32 a, UChar32 b, CanonicalMode canonicalMode = CanonicalMode::UCS2)
{
const CanonicalizationRange* info = canonicalRangeInfoFor(a, canonicalMode);
switch (info->type) {
case CanonicalizeUnique:
return a == b;
case CanonicalizeSet: {
for (const UChar32* set = canonicalCharacterSetInfo(info->value, canonicalMode); (a = *set); ++set) {
if (a == b)
return true;
}
return false;
}
case CanonicalizeRangeLo:
return (a == b) || (a + info->value == b);
case CanonicalizeRangeHi:
return (a == b) || (a - info->value == b);
case CanonicalizeAlternatingAligned:
return (a | 1) == (b | 1);
case CanonicalizeAlternatingUnaligned:
return ((a - 1) | 1) == ((b - 1) | 1);
}
RELEASE_ASSERT_NOT_REACHED();
return false;
}
} } // JSC::Yarr