DecisionInfo (ANTLR 4 Runtime 4.5.1 API)

java.lang.Object
- org.antlr.v4.runtime.atn.DecisionInfo

```
public class DecisionInfo
extends Object
```
This class contains profiling gathered for a particular decision.
Parsing performance in ANTLR 4 is heavily influenced by both static factors (e.g. the form of the rules in the grammar) and dynamic factors (e.g. the choice of input and the state of the DFA cache at the time profiling operations are started). For best results, gather and use aggregate statistics from a large sample of inputs representing the inputs expected in production before using the results to make changes in the grammar.

Since:

4.3

Field Summary

Fields
Modifier and Type	Field and Description
`List<AmbiguityInfo>`	`ambiguities` A collection of `AmbiguityInfo` instances describing the ambiguities encountered during LL prediction for this decision.
`List<ContextSensitivityInfo>`	`contextSensitivities` A collection of `ContextSensitivityInfo` instances describing the context sensitivities encountered during LL prediction for this decision.
`int`	`decision` The decision number, which is an index into `ATN.decisionToState`.
`List<ErrorInfo>`	`errors` A collection of `ErrorInfo` instances describing the parse errors identified during calls to `ParserATNSimulator.adaptivePredict(org.antlr.v4.runtime.TokenStream, int, org.antlr.v4.runtime.ParserRuleContext)` for this decision.
`long`	`invocations` The total number of times `ParserATNSimulator.adaptivePredict(org.antlr.v4.runtime.TokenStream, int, org.antlr.v4.runtime.ParserRuleContext)` was invoked for this decision.
`long`	`LL_ATNTransitions` The total number of ATN transitions required during LL prediction for this decision.
`long`	`LL_DFATransitions` The total number of DFA transitions required during LL prediction for this decision.
`long`	`LL_Fallback` Gets the total number of times SLL prediction completed in a conflict state, resulting in fallback to LL prediction.
`long`	`LL_MaxLook` Gets the maximum lookahead required for any single LL prediction to complete for this decision.
`LookaheadEventInfo`	`LL_MaxLookEvent` Gets the `LookaheadEventInfo` associated with the event where the `LL_MaxLook` value was set.
`long`	`LL_MinLook` Gets the minimum lookahead required for any single LL prediction to complete for this decision.
`long`	`LL_TotalLook` The sum of the lookahead required for LL prediction for this decision.
`List<PredicateEvalInfo>`	`predicateEvals` A collection of `PredicateEvalInfo` instances describing the results of evaluating individual predicates during prediction for this decision.
`long`	`SLL_ATNTransitions` The total number of ATN transitions required during SLL prediction for this decision.
`long`	`SLL_DFATransitions` The total number of DFA transitions required during SLL prediction for this decision.
`long`	`SLL_MaxLook` Gets the maximum lookahead required for any single SLL prediction to complete for this decision, by reaching a unique prediction, reaching an SLL conflict state, or encountering a syntax error.
`LookaheadEventInfo`	`SLL_MaxLookEvent` Gets the `LookaheadEventInfo` associated with the event where the `SLL_MaxLook` value was set.
`long`	`SLL_MinLook` Gets the minimum lookahead required for any single SLL prediction to complete for this decision, by reaching a unique prediction, reaching an SLL conflict state, or encountering a syntax error.
`long`	`SLL_TotalLook` The sum of the lookahead required for SLL prediction for this decision.
`long`	`timeInPrediction` The total time spent in `ParserATNSimulator.adaptivePredict(org.antlr.v4.runtime.TokenStream, int, org.antlr.v4.runtime.ParserRuleContext)` for this decision, in nanoseconds.

Constructor Summary

Constructors
Constructor and Description

DecisionInfo(int decision)
Constructs a new instance of the DecisionInfo class to contain statistics for a particular decision.

Constructors
Constructor and Description
`DecisionInfo(int decision)` Constructs a new instance of the `DecisionInfo` class to contain statistics for a particular decision.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type Method and Description

String toString()
- Methods inherited from class java.lang.Object
  clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`String`	`toString()`

- Field Detail
  - decision
```
public final int decision
```
    The decision number, which is an index into ATN.decisionToState.
  - invocations
```
public long invocations
```
    The total number of times ParserATNSimulator.adaptivePredict(org.antlr.v4.runtime.TokenStream, int, org.antlr.v4.runtime.ParserRuleContext) was invoked for this decision.
  - timeInPrediction
```
public long timeInPrediction
```
    The total time spent in ParserATNSimulator.adaptivePredict(org.antlr.v4.runtime.TokenStream, int, org.antlr.v4.runtime.ParserRuleContext) for this decision, in nanoseconds.
    The value of this field contains the sum of differential results obtained by System.nanoTime(), and is not adjusted to compensate for JIT and/or garbage collection overhead. For best accuracy, use a modern JVM implementation that provides precise results from System.nanoTime(), and perform profiling in a separate process which is warmed up by parsing the input prior to profiling. If desired, call ATNSimulator.clearDFA() to reset the DFA cache to its initial state before starting the profiling measurement pass.
  - SLL_TotalLook
```
public long SLL_TotalLook
```
    The sum of the lookahead required for SLL prediction for this decision. Note that SLL prediction is used before LL prediction for performance reasons even when PredictionMode.LL or PredictionMode.LL_EXACT_AMBIG_DETECTION is used.
  - SLL_MinLook
```
public long SLL_MinLook
```
    Gets the minimum lookahead required for any single SLL prediction to complete for this decision, by reaching a unique prediction, reaching an SLL conflict state, or encountering a syntax error.
  - SLL_MaxLook
```
public long SLL_MaxLook
```
    Gets the maximum lookahead required for any single SLL prediction to complete for this decision, by reaching a unique prediction, reaching an SLL conflict state, or encountering a syntax error.
  - SLL_MaxLookEvent
```
public LookaheadEventInfo SLL_MaxLookEvent
```
    Gets the LookaheadEventInfo associated with the event where the SLL_MaxLook value was set.
  - LL_TotalLook
```
public long LL_TotalLook
```
    The sum of the lookahead required for LL prediction for this decision. Note that LL prediction is only used when SLL prediction reaches a conflict state.
  - LL_MinLook
```
public long LL_MinLook
```
    Gets the minimum lookahead required for any single LL prediction to complete for this decision. An LL prediction completes when the algorithm reaches a unique prediction, a conflict state (for PredictionMode.LL, an ambiguity state (for PredictionMode.LL_EXACT_AMBIG_DETECTION, or a syntax error.
  - LL_MaxLook
```
public long LL_MaxLook
```
    Gets the maximum lookahead required for any single LL prediction to complete for this decision. An LL prediction completes when the algorithm reaches a unique prediction, a conflict state (for PredictionMode.LL, an ambiguity state (for PredictionMode.LL_EXACT_AMBIG_DETECTION, or a syntax error.
  - LL_MaxLookEvent
```
public LookaheadEventInfo LL_MaxLookEvent
```
    Gets the LookaheadEventInfo associated with the event where the LL_MaxLook value was set.
  - contextSensitivities
```
public final List<ContextSensitivityInfo> contextSensitivities
```
    A collection of ContextSensitivityInfo instances describing the context sensitivities encountered during LL prediction for this decision.
    
    See Also:
    
    ContextSensitivityInfo
  - errors
```
public final List<ErrorInfo> errors
```
    A collection of ErrorInfo instances describing the parse errors identified during calls to ParserATNSimulator.adaptivePredict(org.antlr.v4.runtime.TokenStream, int, org.antlr.v4.runtime.ParserRuleContext) for this decision.
    
    See Also:
    
    ErrorInfo
  - ambiguities
```
public final List<AmbiguityInfo> ambiguities
```
    A collection of AmbiguityInfo instances describing the ambiguities encountered during LL prediction for this decision.
    
    See Also:
    
    AmbiguityInfo
  - predicateEvals
```
public final List<PredicateEvalInfo> predicateEvals
```
    A collection of PredicateEvalInfo instances describing the results of evaluating individual predicates during prediction for this decision.
    
    See Also:
    
    PredicateEvalInfo
  - SLL_ATNTransitions
```
public long SLL_ATNTransitions
```
    The total number of ATN transitions required during SLL prediction for this decision. An ATN transition is determined by the number of times the DFA does not contain an edge that is required for prediction, resulting in on-the-fly computation of that edge.
    If DFA caching of SLL transitions is employed by the implementation, ATN computation may cache the computed edge for efficient lookup during future parsing of this decision. Otherwise, the SLL parsing algorithm will use ATN transitions exclusively.
    
    See Also:
    
    SLL_ATNTransitions, ParserATNSimulator.computeTargetState(org.antlr.v4.runtime.dfa.DFA, org.antlr.v4.runtime.dfa.DFAState, int), LexerATNSimulator.computeTargetState(org.antlr.v4.runtime.CharStream, org.antlr.v4.runtime.dfa.DFAState, int)
  - SLL_DFATransitions
```
public long SLL_DFATransitions
```
    The total number of DFA transitions required during SLL prediction for this decision.
    If the ATN simulator implementation does not use DFA caching for SLL transitions, this value will be 0.
    
    See Also:
    
    ParserATNSimulator.getExistingTargetState(org.antlr.v4.runtime.dfa.DFAState, int), LexerATNSimulator.getExistingTargetState(org.antlr.v4.runtime.dfa.DFAState, int)
  - LL_Fallback
```
public long LL_Fallback
```
    Gets the total number of times SLL prediction completed in a conflict state, resulting in fallback to LL prediction.
    Note that this value is not related to whether or not PredictionMode.SLL may be used successfully with a particular grammar. If the ambiguity resolution algorithm applied to the SLL conflicts for this decision produce the same result as LL prediction for this decision, PredictionMode.SLL would produce the same overall parsing result as PredictionMode.LL.
  - LL_ATNTransitions
```
public long LL_ATNTransitions
```
    The total number of ATN transitions required during LL prediction for this decision. An ATN transition is determined by the number of times the DFA does not contain an edge that is required for prediction, resulting in on-the-fly computation of that edge.
    If DFA caching of LL transitions is employed by the implementation, ATN computation may cache the computed edge for efficient lookup during future parsing of this decision. Otherwise, the LL parsing algorithm will use ATN transitions exclusively.
    
    See Also:
    
    LL_DFATransitions, ParserATNSimulator.computeTargetState(org.antlr.v4.runtime.dfa.DFA, org.antlr.v4.runtime.dfa.DFAState, int), LexerATNSimulator.computeTargetState(org.antlr.v4.runtime.CharStream, org.antlr.v4.runtime.dfa.DFAState, int)
  - LL_DFATransitions
```
public long LL_DFATransitions
```
    The total number of DFA transitions required during LL prediction for this decision.
    If the ATN simulator implementation does not use DFA caching for LL transitions, this value will be 0.
    
    See Also:
    
    ParserATNSimulator.getExistingTargetState(org.antlr.v4.runtime.dfa.DFAState, int), LexerATNSimulator.getExistingTargetState(org.antlr.v4.runtime.dfa.DFAState, int)
- Constructor Detail
  - DecisionInfo
```
public DecisionInfo(int decision)
```
    Constructs a new instance of the DecisionInfo class to contain statistics for a particular decision.
    
    Parameters:
    
    decision - The decision number
- Method Detail
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class DecisionInfo

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

decision

invocations

timeInPrediction

SLL_TotalLook

SLL_MinLook

SLL_MaxLook

SLL_MaxLookEvent

LL_TotalLook

LL_MinLook

LL_MaxLook

LL_MaxLookEvent

contextSensitivities

errors

ambiguities

predicateEvals

SLL_ATNTransitions

SLL_DFATransitions

LL_Fallback

LL_ATNTransitions

LL_DFATransitions

Constructor Detail

DecisionInfo

Method Detail

toString