Class DecisionEventInfo

  • Direct Known Subclasses:
    AmbiguityInfo, ContextSensitivityInfo, ErrorInfo, LookaheadEventInfo, PredicateEvalInfo

    public class DecisionEventInfo
    extends Object
    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 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
    • Field Summary

      Fields 
      Modifier and Type Field Description
      ATNConfigSet configs
      The configuration set containing additional information relevant to the prediction state when the current event occurred, or null if no additional information is relevant or available.
      int decision
      The invoked decision number which this event is related to.
      boolean fullCtx
      true if the current event occurred during LL prediction; otherwise, false if the input occurred during SLL prediction.
      TokenStream input
      The input token stream which is being parsed.
      int startIndex
      The token index in the input stream at which the current prediction was originally invoked.
      int stopIndex
      The token index in the input stream at which the current event occurred.
    • Field Detail

      • decision

        public final int decision
        The invoked decision number which this event is related to.
        See Also:
        ATN.decisionToState
      • configs

        public final ATNConfigSet configs
        The configuration set containing additional information relevant to the prediction state when the current event occurred, or null if no additional information is relevant or available.
      • input

        public final TokenStream input
        The input token stream which is being parsed.
      • startIndex

        public final int startIndex
        The token index in the input stream at which the current prediction was originally invoked.
      • stopIndex

        public final int stopIndex
        The token index in the input stream at which the current event occurred.
      • fullCtx

        public final boolean fullCtx
        true if the current event occurred during LL prediction; otherwise, false if the input occurred during SLL prediction.
    • Constructor Detail

      • DecisionEventInfo

        public DecisionEventInfo​(int decision,
                                 ATNConfigSet configs,
                                 TokenStream input,
                                 int startIndex,
                                 int stopIndex,
                                 boolean fullCtx)