67 lines
2.4 KiB
C
67 lines
2.4 KiB
C
|
/* 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/LexerActionType.h"
|
||
|
|
#include "antlr4-common.h"
|
||
|
|
|
||
|
|
namespace antlr4 {
|
||
|
|
namespace atn {
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Represents a single action which can be executed following the successful
|
||
|
|
/// match of a lexer rule. Lexer actions are used for both embedded action syntax
|
||
|
|
/// and ANTLR 4's new lexer command syntax.
|
||
|
|
///
|
||
|
|
/// @author Sam Harwell
|
||
|
|
/// @since 4.2
|
||
|
|
/// </summary>
|
||
|
|
class ANTLR4CPP_PUBLIC LexerAction {
|
||
|
|
public:
|
||
|
|
virtual ~LexerAction();
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Gets the serialization type of the lexer action.
|
||
|
|
/// </summary>
|
||
|
|
/// <returns> The serialization type of the lexer action. </returns>
|
||
|
|
virtual LexerActionType getActionType() const = 0;
|
||
|
|
|
||
|
|
/// <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>Many lexer commands, including {@code type}, {@code skip}, and
|
||
|
|
/// {@code more}, do not check the input index during their execution.
|
||
|
|
/// Actions like this are position-independent, and may be stored more
|
||
|
|
/// efficiently as part of the <seealso cref="LexerATNConfig#lexerActionExecutor"/>.</para>
|
||
|
|
/// </summary>
|
||
|
|
/// <returns> {@code true} if the lexer action semantics can be affected by the
|
||
|
|
/// position of the input <seealso cref="CharStream"/> at the time it is executed;
|
||
|
|
/// otherwise, {@code false}. </returns>
|
||
|
|
virtual bool isPositionDependent() const = 0;
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Execute the lexer action in the context of the specified <seealso cref="Lexer"/>.
|
||
|
|
///
|
||
|
|
/// <para>For position-dependent actions, the input stream must already be
|
||
|
|
/// positioned correctly prior to calling this method.</para>
|
||
|
|
/// </summary>
|
||
|
|
/// <param name="lexer"> The lexer instance. </param>
|
||
|
|
virtual void execute(Lexer *lexer) = 0;
|
||
|
|
|
||
|
|
virtual size_t hashCode() const = 0;
|
||
|
|
virtual bool operator == (const LexerAction &obj) const = 0;
|
||
|
|
virtual bool operator != (const LexerAction &obj) const {
|
||
|
|
return !(*this == obj);
|
||
|
|
}
|
||
|
|
|
||
|
|
virtual std::string toString() const = 0;
|
||
|
|
};
|
||
|
|
|
||
|
|
} // namespace atn
|
||
|
|
} // namespace antlr4
|