diff options
Diffstat (limited to 'antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/LexerActionExecutor.cpp')
| -rw-r--r-- | antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/LexerActionExecutor.cpp | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/LexerActionExecutor.cpp b/antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/LexerActionExecutor.cpp new file mode 100644 index 0000000..1ae510f --- /dev/null +++ b/antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/LexerActionExecutor.cpp @@ -0,0 +1,107 @@ +/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved. + * Use of this file is governed by the BSD 3-clause license that + * can be found in the LICENSE.txt file in the project root. + */ + +#include "misc/MurmurHash.h" +#include "atn/LexerIndexedCustomAction.h" +#include "support/CPPUtils.h" +#include "support/Arrays.h" + +#include "atn/LexerActionExecutor.h" + +using namespace antlr4; +using namespace antlr4::atn; +using namespace antlr4::misc; +using namespace antlrcpp; + +LexerActionExecutor::LexerActionExecutor(const std::vector<Ref<LexerAction>> &lexerActions) + : _lexerActions(lexerActions), _hashCode(generateHashCode()) { +} + +LexerActionExecutor::~LexerActionExecutor() { +} + +Ref<LexerActionExecutor> LexerActionExecutor::append(Ref<LexerActionExecutor> const& lexerActionExecutor, + Ref<LexerAction> const& lexerAction) { + if (lexerActionExecutor == nullptr) { + return std::make_shared<LexerActionExecutor>(std::vector<Ref<LexerAction>> { lexerAction }); + } + + std::vector<Ref<LexerAction>> lexerActions = lexerActionExecutor->_lexerActions; // Make a copy. + lexerActions.push_back(lexerAction); + return std::make_shared<LexerActionExecutor>(lexerActions); +} + +Ref<LexerActionExecutor> LexerActionExecutor::fixOffsetBeforeMatch(int offset) { + std::vector<Ref<LexerAction>> updatedLexerActions; + for (size_t i = 0; i < _lexerActions.size(); i++) { + if (_lexerActions[i]->isPositionDependent() && !is<LexerIndexedCustomAction>(_lexerActions[i])) { + if (updatedLexerActions.empty()) { + updatedLexerActions = _lexerActions; // Make a copy. + } + + updatedLexerActions[i] = std::make_shared<LexerIndexedCustomAction>(offset, _lexerActions[i]); + } + } + + if (updatedLexerActions.empty()) { + return shared_from_this(); + } + + return std::make_shared<LexerActionExecutor>(updatedLexerActions); +} + +std::vector<Ref<LexerAction>> LexerActionExecutor::getLexerActions() const { + return _lexerActions; +} + +void LexerActionExecutor::execute(Lexer *lexer, CharStream *input, size_t startIndex) { + bool requiresSeek = false; + size_t stopIndex = input->index(); + + auto onExit = finally([requiresSeek, input, stopIndex]() { + if (requiresSeek) { + input->seek(stopIndex); + } + }); + for (auto lexerAction : _lexerActions) { + if (is<LexerIndexedCustomAction>(lexerAction)) { + int offset = (std::static_pointer_cast<LexerIndexedCustomAction>(lexerAction))->getOffset(); + input->seek(startIndex + offset); + lexerAction = std::static_pointer_cast<LexerIndexedCustomAction>(lexerAction)->getAction(); + requiresSeek = (startIndex + offset) != stopIndex; + } else if (lexerAction->isPositionDependent()) { + input->seek(stopIndex); + requiresSeek = false; + } + + lexerAction->execute(lexer); + } +} + +size_t LexerActionExecutor::hashCode() const { + return _hashCode; +} + +bool LexerActionExecutor::operator == (const LexerActionExecutor &obj) const { + if (&obj == this) { + return true; + } + + return _hashCode == obj._hashCode && Arrays::equals(_lexerActions, obj._lexerActions); +} + +bool LexerActionExecutor::operator != (const LexerActionExecutor &obj) const { + return !operator==(obj); +} + +size_t LexerActionExecutor::generateHashCode() const { + size_t hash = MurmurHash::initialize(); + for (auto lexerAction : _lexerActions) { + hash = MurmurHash::update(hash, lexerAction); + } + hash = MurmurHash::finish(hash, _lexerActions.size()); + + return hash; +} |
