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[toc] / antlr4-cpp-runtime-4.9.2-source / runtime / src / atn / LexerIndexedCustomAction.h

diff --git a/antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/LexerIndexedCustomAction.h b/antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/LexerIndexedCustomAction.h
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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:
+    /// <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<LexerAction> const& 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;
+
+    /// <summary>
+    /// Gets the lexer action to execute.
+    /// </summary>
+    /// <returns> A <seealso cref="LexerAction"/> object which executes the lexer action. </returns>
+    Ref<LexerAction> getAction() const;
+
+    /// <summary>
+    /// {@inheritDoc}
+    /// </summary>
+    /// <returns> This method returns the result of calling <seealso cref="#getActionType"/>
+    /// on the <seealso cref="LexerAction"/> returned by <seealso cref="#getAction"/>. </returns>
+    virtual LexerActionType getActionType() const override;
+
+    /// <summary>
+    /// {@inheritDoc} </summary>
+    /// <returns> This method returns {@code true}. </returns>
+    virtual bool isPositionDependent() const override;
+
+    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 int _offset;
+    const Ref<LexerAction> _action;
+  };
+
+} // namespace atn
+} // namespace antlr4
+