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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 "atn/LexerAction.h"
#include "atn/LexerActionType.h"
namespace antlr4 {
namespace atn {
/// <summary>
/// Executes a custom lexer action by calling <seealso cref="Recognizer#action"/> with the
/// rule and action indexes assigned to the custom action. The implementation of
/// a custom action is added to the generated code for the lexer in an override
/// of <seealso cref="Recognizer#action"/> when the grammar is compiled.
///
/// <para>This class may represent embedded actions created with the <code>{...}</code>
/// syntax in ANTLR 4, as well as actions created for lexer commands where the
/// command argument could not be evaluated when the grammar was compiled.</para>
///
/// @author Sam Harwell
/// @since 4.2
/// </summary>
class ANTLR4CPP_PUBLIC LexerCustomAction final : public LexerAction {
public:
/// <summary>
/// Constructs a custom lexer action with the specified rule and action
/// indexes.
/// </summary>
/// <param name="ruleIndex"> The rule index to use for calls to
/// <seealso cref="Recognizer#action"/>. </param>
/// <param name="actionIndex"> The action index to use for calls to
/// <seealso cref="Recognizer#action"/>. </param>
LexerCustomAction(size_t ruleIndex, size_t actionIndex);
/// <summary>
/// Gets the rule index to use for calls to <seealso cref="Recognizer#action"/>.
/// </summary>
/// <returns> The rule index for the custom action. </returns>
size_t getRuleIndex() const;
/// <summary>
/// Gets the action index to use for calls to <seealso cref="Recognizer#action"/>.
/// </summary>
/// <returns> The action index for the custom action. </returns>
size_t getActionIndex() const;
/// <summary>
/// {@inheritDoc}
/// </summary>
/// <returns> This method returns <seealso cref="LexerActionType#CUSTOM"/>. </returns>
virtual LexerActionType getActionType() const override;
/// <summary>
/// Gets whether the lexer action is position-dependent. Position-dependent
/// actions may have different semantics depending on the <seealso cref="CharStream"/>
/// index at the time the action is executed.
///
/// <para>Custom actions are position-dependent since they may represent a
/// user-defined embedded action which makes calls to methods like
/// <seealso cref="Lexer#getText"/>.</para>
/// </summary>
/// <returns> This method returns {@code true}. </returns>
virtual bool isPositionDependent() const override;
/// <summary>
/// {@inheritDoc}
///
/// <para>Custom actions are implemented by calling <seealso cref="Lexer#action"/> with the
/// appropriate rule and action indexes.</para>
/// </summary>
virtual void execute(Lexer *lexer) override;
virtual size_t hashCode() const override;
virtual bool operator == (const LexerAction &obj) const override;
virtual std::string toString() const override;
private:
const size_t _ruleIndex;
const size_t _actionIndex;
};
} // namespace atn
} // namespace antlr4
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