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Diffstat (limited to 'antlr4-cpp-runtime-4.9.2-source/install/include/antlr4-runtime/atn/LexerAction.h')
| -rw-r--r-- | antlr4-cpp-runtime-4.9.2-source/install/include/antlr4-runtime/atn/LexerAction.h | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/antlr4-cpp-runtime-4.9.2-source/install/include/antlr4-runtime/atn/LexerAction.h b/antlr4-cpp-runtime-4.9.2-source/install/include/antlr4-runtime/atn/LexerAction.h new file mode 100644 index 0000000..8e833b6 --- /dev/null +++ b/antlr4-cpp-runtime-4.9.2-source/install/include/antlr4-runtime/atn/LexerAction.h @@ -0,0 +1,66 @@ +/* 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 |
