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/* 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.
*/
#pragma once
#include "RuleContext.h"
#include "atn/LexerAction.h"
namespace antlr4 {
namespace atn {
/// <summary>
/// This implementation of <seealso cref="LexerAction"/> is used for tracking input offsets
/// for position-dependent actions within a <seealso cref="LexerActionExecutor"/>.
///
/// <para>This action is not serialized as part of the ATN, and is only required for
/// position-dependent lexer actions which appear at a location other than the
/// end of a rule. For more information about DFA optimizations employed for
/// lexer actions, see <seealso cref="LexerActionExecutor#append"/> and
/// <seealso cref="LexerActionExecutor#fixOffsetBeforeMatch"/>.</para>
///
/// @author Sam Harwell
/// @since 4.2
/// </summary>
class ANTLR4CPP_PUBLIC LexerIndexedCustomAction final : public LexerAction {
public:
static bool is(const LexerAction &lexerAction) { return lexerAction.getActionType() == LexerActionType::INDEXED_CUSTOM; }
static bool is(const LexerAction *lexerAction) { return lexerAction != nullptr && is(*lexerAction); }
/// <summary>
/// Constructs a new indexed custom action by associating a character offset
/// with a <seealso cref="LexerAction"/>.
///
/// <para>Note: This class is only required for lexer actions for which
/// <seealso cref="LexerAction#isPositionDependent"/> returns {@code true}.</para>
/// </summary>
/// <param name="offset"> The offset into the input <seealso cref="CharStream"/>, relative to
/// the token start index, at which the specified lexer action should be
/// executed. </param>
/// <param name="action"> The lexer action to execute at a particular offset in the
/// input <seealso cref="CharStream"/>. </param>
LexerIndexedCustomAction(int offset, Ref<const LexerAction> action);
/// <summary>
/// Gets the location in the input <seealso cref="CharStream"/> at which the lexer
/// action should be executed. The value is interpreted as an offset relative
/// to the token start index.
/// </summary>
/// <returns> The location in the input <seealso cref="CharStream"/> at which the lexer
/// action should be executed. </returns>
int getOffset() const { return _offset; }
/// <summary>
/// Gets the lexer action to execute.
/// </summary>
/// <returns> A <seealso cref="LexerAction"/> object which executes the lexer action. </returns>
const Ref<const LexerAction>& getAction() const { return _action; }
void execute(Lexer *lexer) const override;
bool equals(const LexerAction &other) const override;
std::string toString() const override;
protected:
size_t hashCodeImpl() const override;
private:
const Ref<const LexerAction> _action;
const int _offset;
};
} // namespace atn
} // namespace antlr4
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