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

diff --git a/antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/DecisionEventInfo.h b/antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/DecisionEventInfo.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 "antlr4-common.h"
+
+namespace antlr4 {
+namespace atn {
+
+  /// <summary>
+  /// This is the base class for gathering detailed information about prediction
+  /// events which occur during parsing.
+  ///
+  /// Note that we could record the parser call stack at the time this event
+  /// occurred but in the presence of left recursive rules, the stack is kind of
+  /// meaningless. It's better to look at the individual configurations for their
+  /// individual stacks. Of course that is a <seealso cref="PredictionContext"/> object
+  /// not a parse tree node and so it does not have information about the extent
+  /// (start...stop) of the various subtrees. Examining the stack tops of all
+  /// configurations provide the return states for the rule invocations.
+  /// From there you can get the enclosing rule.
+  ///
+  /// @since 4.3
+  /// </summary>
+  class ANTLR4CPP_PUBLIC DecisionEventInfo {
+  public:
+    /// <summary>
+    /// The invoked decision number which this event is related to.
+    /// </summary>
+    /// <seealso cref= ATN#decisionToState </seealso>
+    const size_t decision;
+
+    /// <summary>
+    /// The configuration set containing additional information relevant to the
+    /// prediction state when the current event occurred, or {@code null} if no
+    /// additional information is relevant or available.
+    /// </summary>
+    const ATNConfigSet *configs;
+
+    /// <summary>
+    /// The input token stream which is being parsed.
+    /// </summary>
+    const TokenStream *input;
+
+    /// <summary>
+    /// The token index in the input stream at which the current prediction was
+    /// originally invoked.
+    /// </summary>
+    const size_t startIndex;
+
+    /// <summary>
+    /// The token index in the input stream at which the current event occurred.
+    /// </summary>
+    const size_t stopIndex;
+
+    /// <summary>
+    /// {@code true} if the current event occurred during LL prediction;
+    /// otherwise, {@code false} if the input occurred during SLL prediction.
+    /// </summary>
+    const bool fullCtx;
+
+    DecisionEventInfo(size_t decision, ATNConfigSet *configs, TokenStream *input, size_t startIndex,
+                      size_t stopIndex, bool fullCtx);
+  };
+
+} // namespace atn
+} // namespace antlr4