mirror of
https://github.com/ZDoom/Raze.git
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701 lines
24 KiB
C++
701 lines
24 KiB
C++
// Tencent is pleased to support the open source community by making RapidJSON available.
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//
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// Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved.
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//
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// Licensed under the MIT License (the "License"); you may not use this file except
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// in compliance with the License. You may obtain a copy of the License at
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//
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// http://opensource.org/licenses/MIT
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//
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// Unless required by applicable law or agreed to in writing, software distributed
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// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
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// CONDITIONS OF ANY KIND, either express or implied. See the License for the
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// specific language governing permissions and limitations under the License.
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#ifndef RAPIDJSON_INTERNAL_REGEX_H_
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#define RAPIDJSON_INTERNAL_REGEX_H_
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#include "../allocators.h"
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#include "../stream.h"
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#include "stack.h"
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#ifdef __clang__
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RAPIDJSON_DIAG_PUSH
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RAPIDJSON_DIAG_OFF(padded)
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RAPIDJSON_DIAG_OFF(switch-enum)
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RAPIDJSON_DIAG_OFF(implicit-fallthrough)
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#endif
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#ifdef __GNUC__
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RAPIDJSON_DIAG_PUSH
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RAPIDJSON_DIAG_OFF(effc++)
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#endif
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#ifdef _MSC_VER
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RAPIDJSON_DIAG_PUSH
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RAPIDJSON_DIAG_OFF(4512) // assignment operator could not be generated
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#endif
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#ifndef RAPIDJSON_REGEX_VERBOSE
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#define RAPIDJSON_REGEX_VERBOSE 0
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#endif
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RAPIDJSON_NAMESPACE_BEGIN
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namespace internal {
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///////////////////////////////////////////////////////////////////////////////
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// GenericRegex
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static const SizeType kRegexInvalidState = ~SizeType(0); //!< Represents an invalid index in GenericRegex::State::out, out1
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static const SizeType kRegexInvalidRange = ~SizeType(0);
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//! Regular expression engine with subset of ECMAscript grammar.
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/*!
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Supported regular expression syntax:
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- \c ab Concatenation
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- \c a|b Alternation
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- \c a? Zero or one
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- \c a* Zero or more
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- \c a+ One or more
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- \c a{3} Exactly 3 times
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- \c a{3,} At least 3 times
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- \c a{3,5} 3 to 5 times
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- \c (ab) Grouping
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- \c ^a At the beginning
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- \c a$ At the end
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- \c . Any character
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- \c [abc] Character classes
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- \c [a-c] Character class range
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- \c [a-z0-9_] Character class combination
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- \c [^abc] Negated character classes
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- \c [^a-c] Negated character class range
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- \c [\b] Backspace (U+0008)
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- \c \\| \\\\ ... Escape characters
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- \c \\f Form feed (U+000C)
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- \c \\n Line feed (U+000A)
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- \c \\r Carriage return (U+000D)
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- \c \\t Tab (U+0009)
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- \c \\v Vertical tab (U+000B)
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\note This is a Thompson NFA engine, implemented with reference to
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Cox, Russ. "Regular Expression Matching Can Be Simple And Fast (but is slow in Java, Perl, PHP, Python, Ruby,...).",
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https://swtch.com/~rsc/regexp/regexp1.html
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*/
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template <typename Encoding, typename Allocator = CrtAllocator>
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class GenericRegex {
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public:
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typedef typename Encoding::Ch Ch;
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GenericRegex(const Ch* source, Allocator* allocator = 0) :
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states_(allocator, 256), ranges_(allocator, 256), root_(kRegexInvalidState), stateCount_(), rangeCount_(),
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stateSet_(), state0_(allocator, 0), state1_(allocator, 0), anchorBegin_(), anchorEnd_()
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{
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GenericStringStream<Encoding> ss(source);
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DecodedStream<GenericStringStream<Encoding> > ds(ss);
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Parse(ds);
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}
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~GenericRegex() {
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Allocator::Free(stateSet_);
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}
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bool IsValid() const {
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return root_ != kRegexInvalidState;
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}
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template <typename InputStream>
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bool Match(InputStream& is) const {
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return SearchWithAnchoring(is, true, true);
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}
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bool Match(const Ch* s) const {
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GenericStringStream<Encoding> is(s);
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return Match(is);
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}
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template <typename InputStream>
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bool Search(InputStream& is) const {
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return SearchWithAnchoring(is, anchorBegin_, anchorEnd_);
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}
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bool Search(const Ch* s) const {
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GenericStringStream<Encoding> is(s);
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return Search(is);
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}
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private:
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enum Operator {
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kZeroOrOne,
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kZeroOrMore,
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kOneOrMore,
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kConcatenation,
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kAlternation,
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kLeftParenthesis
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};
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static const unsigned kAnyCharacterClass = 0xFFFFFFFF; //!< For '.'
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static const unsigned kRangeCharacterClass = 0xFFFFFFFE;
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static const unsigned kRangeNegationFlag = 0x80000000;
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struct Range {
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unsigned start; //
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unsigned end;
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SizeType next;
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};
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struct State {
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SizeType out; //!< Equals to kInvalid for matching state
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SizeType out1; //!< Equals to non-kInvalid for split
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SizeType rangeStart;
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unsigned codepoint;
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};
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struct Frag {
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Frag(SizeType s, SizeType o, SizeType m) : start(s), out(o), minIndex(m) {}
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SizeType start;
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SizeType out; //!< link-list of all output states
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SizeType minIndex;
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};
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template <typename SourceStream>
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class DecodedStream {
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public:
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DecodedStream(SourceStream& ss) : ss_(ss), codepoint_() { Decode(); }
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unsigned Peek() { return codepoint_; }
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unsigned Take() {
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unsigned c = codepoint_;
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if (c) // No further decoding when '\0'
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Decode();
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return c;
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}
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private:
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void Decode() {
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if (!Encoding::Decode(ss_, &codepoint_))
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codepoint_ = 0;
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}
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SourceStream& ss_;
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unsigned codepoint_;
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};
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State& GetState(SizeType index) {
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RAPIDJSON_ASSERT(index < stateCount_);
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return states_.template Bottom<State>()[index];
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}
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const State& GetState(SizeType index) const {
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RAPIDJSON_ASSERT(index < stateCount_);
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return states_.template Bottom<State>()[index];
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}
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Range& GetRange(SizeType index) {
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RAPIDJSON_ASSERT(index < rangeCount_);
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return ranges_.template Bottom<Range>()[index];
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}
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const Range& GetRange(SizeType index) const {
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RAPIDJSON_ASSERT(index < rangeCount_);
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return ranges_.template Bottom<Range>()[index];
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}
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template <typename InputStream>
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void Parse(DecodedStream<InputStream>& ds) {
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Allocator allocator;
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Stack<Allocator> operandStack(&allocator, 256); // Frag
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Stack<Allocator> operatorStack(&allocator, 256); // Operator
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Stack<Allocator> atomCountStack(&allocator, 256); // unsigned (Atom per parenthesis)
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*atomCountStack.template Push<unsigned>() = 0;
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unsigned codepoint;
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while (ds.Peek() != 0) {
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switch (codepoint = ds.Take()) {
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case '^':
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anchorBegin_ = true;
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break;
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case '$':
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anchorEnd_ = true;
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break;
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case '|':
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while (!operatorStack.Empty() && *operatorStack.template Top<Operator>() < kAlternation)
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if (!Eval(operandStack, *operatorStack.template Pop<Operator>(1)))
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return;
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*operatorStack.template Push<Operator>() = kAlternation;
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*atomCountStack.template Top<unsigned>() = 0;
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break;
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case '(':
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*operatorStack.template Push<Operator>() = kLeftParenthesis;
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*atomCountStack.template Push<unsigned>() = 0;
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break;
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case ')':
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while (!operatorStack.Empty() && *operatorStack.template Top<Operator>() != kLeftParenthesis)
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if (!Eval(operandStack, *operatorStack.template Pop<Operator>(1)))
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return;
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if (operatorStack.Empty())
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return;
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operatorStack.template Pop<Operator>(1);
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atomCountStack.template Pop<unsigned>(1);
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ImplicitConcatenation(atomCountStack, operatorStack);
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break;
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case '?':
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if (!Eval(operandStack, kZeroOrOne))
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return;
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break;
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case '*':
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if (!Eval(operandStack, kZeroOrMore))
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return;
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break;
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case '+':
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if (!Eval(operandStack, kOneOrMore))
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return;
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break;
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case '{':
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{
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unsigned n, m;
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if (!ParseUnsigned(ds, &n))
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return;
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if (ds.Peek() == ',') {
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ds.Take();
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if (ds.Peek() == '}')
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m = kInfinityQuantifier;
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else if (!ParseUnsigned(ds, &m) || m < n)
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return;
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}
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else
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m = n;
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if (!EvalQuantifier(operandStack, n, m) || ds.Peek() != '}')
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return;
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ds.Take();
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}
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break;
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case '.':
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PushOperand(operandStack, kAnyCharacterClass);
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ImplicitConcatenation(atomCountStack, operatorStack);
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break;
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case '[':
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{
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SizeType range;
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if (!ParseRange(ds, &range))
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return;
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SizeType s = NewState(kRegexInvalidState, kRegexInvalidState, kRangeCharacterClass);
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GetState(s).rangeStart = range;
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*operandStack.template Push<Frag>() = Frag(s, s, s);
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}
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ImplicitConcatenation(atomCountStack, operatorStack);
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break;
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case '\\': // Escape character
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if (!CharacterEscape(ds, &codepoint))
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return; // Unsupported escape character
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// fall through to default
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default: // Pattern character
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PushOperand(operandStack, codepoint);
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ImplicitConcatenation(atomCountStack, operatorStack);
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}
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}
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while (!operatorStack.Empty())
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if (!Eval(operandStack, *operatorStack.template Pop<Operator>(1)))
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return;
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// Link the operand to matching state.
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if (operandStack.GetSize() == sizeof(Frag)) {
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Frag* e = operandStack.template Pop<Frag>(1);
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Patch(e->out, NewState(kRegexInvalidState, kRegexInvalidState, 0));
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root_ = e->start;
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#if RAPIDJSON_REGEX_VERBOSE
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printf("root: %d\n", root_);
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for (SizeType i = 0; i < stateCount_ ; i++) {
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State& s = GetState(i);
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printf("[%2d] out: %2d out1: %2d c: '%c'\n", i, s.out, s.out1, (char)s.codepoint);
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}
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printf("\n");
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#endif
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}
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// Preallocate buffer for SearchWithAnchoring()
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RAPIDJSON_ASSERT(stateSet_ == 0);
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if (stateCount_ > 0) {
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stateSet_ = static_cast<unsigned*>(states_.GetAllocator().Malloc(GetStateSetSize()));
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state0_.template Reserve<SizeType>(stateCount_);
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state1_.template Reserve<SizeType>(stateCount_);
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}
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}
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SizeType NewState(SizeType out, SizeType out1, unsigned codepoint) {
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State* s = states_.template Push<State>();
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s->out = out;
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s->out1 = out1;
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s->codepoint = codepoint;
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s->rangeStart = kRegexInvalidRange;
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return stateCount_++;
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}
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void PushOperand(Stack<Allocator>& operandStack, unsigned codepoint) {
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SizeType s = NewState(kRegexInvalidState, kRegexInvalidState, codepoint);
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*operandStack.template Push<Frag>() = Frag(s, s, s);
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}
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void ImplicitConcatenation(Stack<Allocator>& atomCountStack, Stack<Allocator>& operatorStack) {
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if (*atomCountStack.template Top<unsigned>())
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*operatorStack.template Push<Operator>() = kConcatenation;
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(*atomCountStack.template Top<unsigned>())++;
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}
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SizeType Append(SizeType l1, SizeType l2) {
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SizeType old = l1;
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while (GetState(l1).out != kRegexInvalidState)
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l1 = GetState(l1).out;
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GetState(l1).out = l2;
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return old;
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}
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void Patch(SizeType l, SizeType s) {
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for (SizeType next; l != kRegexInvalidState; l = next) {
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next = GetState(l).out;
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GetState(l).out = s;
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}
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}
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bool Eval(Stack<Allocator>& operandStack, Operator op) {
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switch (op) {
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case kConcatenation:
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RAPIDJSON_ASSERT(operandStack.GetSize() >= sizeof(Frag) * 2);
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{
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Frag e2 = *operandStack.template Pop<Frag>(1);
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Frag e1 = *operandStack.template Pop<Frag>(1);
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Patch(e1.out, e2.start);
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*operandStack.template Push<Frag>() = Frag(e1.start, e2.out, Min(e1.minIndex, e2.minIndex));
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}
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return true;
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case kAlternation:
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if (operandStack.GetSize() >= sizeof(Frag) * 2) {
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Frag e2 = *operandStack.template Pop<Frag>(1);
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Frag e1 = *operandStack.template Pop<Frag>(1);
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SizeType s = NewState(e1.start, e2.start, 0);
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*operandStack.template Push<Frag>() = Frag(s, Append(e1.out, e2.out), Min(e1.minIndex, e2.minIndex));
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return true;
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}
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return false;
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case kZeroOrOne:
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if (operandStack.GetSize() >= sizeof(Frag)) {
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Frag e = *operandStack.template Pop<Frag>(1);
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SizeType s = NewState(kRegexInvalidState, e.start, 0);
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*operandStack.template Push<Frag>() = Frag(s, Append(e.out, s), e.minIndex);
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return true;
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}
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return false;
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case kZeroOrMore:
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if (operandStack.GetSize() >= sizeof(Frag)) {
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Frag e = *operandStack.template Pop<Frag>(1);
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SizeType s = NewState(kRegexInvalidState, e.start, 0);
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Patch(e.out, s);
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*operandStack.template Push<Frag>() = Frag(s, s, e.minIndex);
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return true;
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}
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return false;
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default:
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RAPIDJSON_ASSERT(op == kOneOrMore);
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if (operandStack.GetSize() >= sizeof(Frag)) {
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Frag e = *operandStack.template Pop<Frag>(1);
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SizeType s = NewState(kRegexInvalidState, e.start, 0);
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Patch(e.out, s);
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*operandStack.template Push<Frag>() = Frag(e.start, s, e.minIndex);
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return true;
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}
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return false;
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}
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}
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bool EvalQuantifier(Stack<Allocator>& operandStack, unsigned n, unsigned m) {
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RAPIDJSON_ASSERT(n <= m);
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RAPIDJSON_ASSERT(operandStack.GetSize() >= sizeof(Frag));
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if (n == 0) {
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if (m == 0) // a{0} not support
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return false;
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else if (m == kInfinityQuantifier)
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Eval(operandStack, kZeroOrMore); // a{0,} -> a*
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else {
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Eval(operandStack, kZeroOrOne); // a{0,5} -> a?
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for (unsigned i = 0; i < m - 1; i++)
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CloneTopOperand(operandStack); // a{0,5} -> a? a? a? a? a?
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for (unsigned i = 0; i < m - 1; i++)
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Eval(operandStack, kConcatenation); // a{0,5} -> a?a?a?a?a?
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}
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return true;
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}
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for (unsigned i = 0; i < n - 1; i++) // a{3} -> a a a
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CloneTopOperand(operandStack);
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if (m == kInfinityQuantifier)
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Eval(operandStack, kOneOrMore); // a{3,} -> a a a+
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else if (m > n) {
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CloneTopOperand(operandStack); // a{3,5} -> a a a a
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Eval(operandStack, kZeroOrOne); // a{3,5} -> a a a a?
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for (unsigned i = n; i < m - 1; i++)
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CloneTopOperand(operandStack); // a{3,5} -> a a a a? a?
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for (unsigned i = n; i < m; i++)
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Eval(operandStack, kConcatenation); // a{3,5} -> a a aa?a?
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}
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for (unsigned i = 0; i < n - 1; i++)
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Eval(operandStack, kConcatenation); // a{3} -> aaa, a{3,} -> aaa+, a{3.5} -> aaaa?a?
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return true;
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}
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static SizeType Min(SizeType a, SizeType b) { return a < b ? a : b; }
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void CloneTopOperand(Stack<Allocator>& operandStack) {
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const Frag src = *operandStack.template Top<Frag>(); // Copy constructor to prevent invalidation
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SizeType count = stateCount_ - src.minIndex; // Assumes top operand contains states in [src->minIndex, stateCount_)
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State* s = states_.template Push<State>(count);
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memcpy(s, &GetState(src.minIndex), count * sizeof(State));
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for (SizeType j = 0; j < count; j++) {
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if (s[j].out != kRegexInvalidState)
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s[j].out += count;
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if (s[j].out1 != kRegexInvalidState)
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s[j].out1 += count;
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}
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*operandStack.template Push<Frag>() = Frag(src.start + count, src.out + count, src.minIndex + count);
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stateCount_ += count;
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}
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template <typename InputStream>
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bool ParseUnsigned(DecodedStream<InputStream>& ds, unsigned* u) {
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unsigned r = 0;
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if (ds.Peek() < '0' || ds.Peek() > '9')
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return false;
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while (ds.Peek() >= '0' && ds.Peek() <= '9') {
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if (r >= 429496729 && ds.Peek() > '5') // 2^32 - 1 = 4294967295
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return false; // overflow
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r = r * 10 + (ds.Take() - '0');
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}
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*u = r;
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return true;
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}
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template <typename InputStream>
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bool ParseRange(DecodedStream<InputStream>& ds, SizeType* range) {
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bool isBegin = true;
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|
bool negate = false;
|
|
int step = 0;
|
|
SizeType start = kRegexInvalidRange;
|
|
SizeType current = kRegexInvalidRange;
|
|
unsigned codepoint;
|
|
while ((codepoint = ds.Take()) != 0) {
|
|
if (isBegin) {
|
|
isBegin = false;
|
|
if (codepoint == '^') {
|
|
negate = true;
|
|
continue;
|
|
}
|
|
}
|
|
|
|
switch (codepoint) {
|
|
case ']':
|
|
if (start == kRegexInvalidRange)
|
|
return false; // Error: nothing inside []
|
|
if (step == 2) { // Add trailing '-'
|
|
SizeType r = NewRange('-');
|
|
RAPIDJSON_ASSERT(current != kRegexInvalidRange);
|
|
GetRange(current).next = r;
|
|
}
|
|
if (negate)
|
|
GetRange(start).start |= kRangeNegationFlag;
|
|
*range = start;
|
|
return true;
|
|
|
|
case '\\':
|
|
if (ds.Peek() == 'b') {
|
|
ds.Take();
|
|
codepoint = 0x0008; // Escape backspace character
|
|
}
|
|
else if (!CharacterEscape(ds, &codepoint))
|
|
return false;
|
|
// fall through to default
|
|
|
|
default:
|
|
switch (step) {
|
|
case 1:
|
|
if (codepoint == '-') {
|
|
step++;
|
|
break;
|
|
}
|
|
// fall through to step 0 for other characters
|
|
|
|
case 0:
|
|
{
|
|
SizeType r = NewRange(codepoint);
|
|
if (current != kRegexInvalidRange)
|
|
GetRange(current).next = r;
|
|
if (start == kRegexInvalidRange)
|
|
start = r;
|
|
current = r;
|
|
}
|
|
step = 1;
|
|
break;
|
|
|
|
default:
|
|
RAPIDJSON_ASSERT(step == 2);
|
|
GetRange(current).end = codepoint;
|
|
step = 0;
|
|
}
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
SizeType NewRange(unsigned codepoint) {
|
|
Range* r = ranges_.template Push<Range>();
|
|
r->start = r->end = codepoint;
|
|
r->next = kRegexInvalidRange;
|
|
return rangeCount_++;
|
|
}
|
|
|
|
template <typename InputStream>
|
|
bool CharacterEscape(DecodedStream<InputStream>& ds, unsigned* escapedCodepoint) {
|
|
unsigned codepoint;
|
|
switch (codepoint = ds.Take()) {
|
|
case '^':
|
|
case '$':
|
|
case '|':
|
|
case '(':
|
|
case ')':
|
|
case '?':
|
|
case '*':
|
|
case '+':
|
|
case '.':
|
|
case '[':
|
|
case ']':
|
|
case '{':
|
|
case '}':
|
|
case '\\':
|
|
*escapedCodepoint = codepoint; return true;
|
|
case 'f': *escapedCodepoint = 0x000C; return true;
|
|
case 'n': *escapedCodepoint = 0x000A; return true;
|
|
case 'r': *escapedCodepoint = 0x000D; return true;
|
|
case 't': *escapedCodepoint = 0x0009; return true;
|
|
case 'v': *escapedCodepoint = 0x000B; return true;
|
|
default:
|
|
return false; // Unsupported escape character
|
|
}
|
|
}
|
|
|
|
template <typename InputStream>
|
|
bool SearchWithAnchoring(InputStream& is, bool anchorBegin, bool anchorEnd) const {
|
|
RAPIDJSON_ASSERT(IsValid());
|
|
DecodedStream<InputStream> ds(is);
|
|
|
|
state0_.Clear();
|
|
Stack<Allocator> *current = &state0_, *next = &state1_;
|
|
const size_t stateSetSize = GetStateSetSize();
|
|
std::memset(stateSet_, 0, stateSetSize);
|
|
|
|
bool matched = AddState(*current, root_);
|
|
unsigned codepoint;
|
|
while (!current->Empty() && (codepoint = ds.Take()) != 0) {
|
|
std::memset(stateSet_, 0, stateSetSize);
|
|
next->Clear();
|
|
matched = false;
|
|
for (const SizeType* s = current->template Bottom<SizeType>(); s != current->template End<SizeType>(); ++s) {
|
|
const State& sr = GetState(*s);
|
|
if (sr.codepoint == codepoint ||
|
|
sr.codepoint == kAnyCharacterClass ||
|
|
(sr.codepoint == kRangeCharacterClass && MatchRange(sr.rangeStart, codepoint)))
|
|
{
|
|
matched = AddState(*next, sr.out) || matched;
|
|
if (!anchorEnd && matched)
|
|
return true;
|
|
}
|
|
if (!anchorBegin)
|
|
AddState(*next, root_);
|
|
}
|
|
internal::Swap(current, next);
|
|
}
|
|
|
|
return matched;
|
|
}
|
|
|
|
size_t GetStateSetSize() const {
|
|
return (stateCount_ + 31) / 32 * 4;
|
|
}
|
|
|
|
// Return whether the added states is a match state
|
|
bool AddState(Stack<Allocator>& l, SizeType index) const {
|
|
RAPIDJSON_ASSERT(index != kRegexInvalidState);
|
|
|
|
const State& s = GetState(index);
|
|
if (s.out1 != kRegexInvalidState) { // Split
|
|
bool matched = AddState(l, s.out);
|
|
return AddState(l, s.out1) || matched;
|
|
}
|
|
else if (!(stateSet_[index >> 5] & (1 << (index & 31)))) {
|
|
stateSet_[index >> 5] |= (1 << (index & 31));
|
|
*l.template PushUnsafe<SizeType>() = index;
|
|
}
|
|
return s.out == kRegexInvalidState; // by using PushUnsafe() above, we can ensure s is not validated due to reallocation.
|
|
}
|
|
|
|
bool MatchRange(SizeType rangeIndex, unsigned codepoint) const {
|
|
bool yes = (GetRange(rangeIndex).start & kRangeNegationFlag) == 0;
|
|
while (rangeIndex != kRegexInvalidRange) {
|
|
const Range& r = GetRange(rangeIndex);
|
|
if (codepoint >= (r.start & ~kRangeNegationFlag) && codepoint <= r.end)
|
|
return yes;
|
|
rangeIndex = r.next;
|
|
}
|
|
return !yes;
|
|
}
|
|
|
|
Stack<Allocator> states_;
|
|
Stack<Allocator> ranges_;
|
|
SizeType root_;
|
|
SizeType stateCount_;
|
|
SizeType rangeCount_;
|
|
|
|
static const unsigned kInfinityQuantifier = ~0u;
|
|
|
|
// For SearchWithAnchoring()
|
|
uint32_t* stateSet_; // allocated by states_.GetAllocator()
|
|
mutable Stack<Allocator> state0_;
|
|
mutable Stack<Allocator> state1_;
|
|
bool anchorBegin_;
|
|
bool anchorEnd_;
|
|
};
|
|
|
|
typedef GenericRegex<UTF8<> > Regex;
|
|
|
|
} // namespace internal
|
|
RAPIDJSON_NAMESPACE_END
|
|
|
|
#ifdef __clang__
|
|
RAPIDJSON_DIAG_POP
|
|
#endif
|
|
|
|
#ifdef _MSC_VER
|
|
RAPIDJSON_DIAG_POP
|
|
#endif
|
|
|
|
#endif // RAPIDJSON_INTERNAL_REGEX_H_
|