Class ATNConfig
- Direct Known Subclasses:
LexerATNConfig
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Field Summary
FieldsModifier and TypeFieldDescriptionfinal int
What alt (or lexer rule) is predicted by this configurationThe stack of invoking states leading to the rule/states associated with this config.int
We cannot execute predicates dependent upon local context unless we know for sure we are in the correct context.final SemanticContext
final ATNState
The ATN state associated with this configuration -
Constructor Summary
ConstructorsConstructorDescriptionATNConfig
(ATNConfig c, ATNState state, PredictionContext context) ATNConfig
(ATNConfig c, ATNState state, PredictionContext context, SemanticContext semanticContext) ATNConfig
(ATNConfig c, ATNState state, SemanticContext semanticContext) ATNConfig
(ATNConfig c, SemanticContext semanticContext) ATNConfig
(ATNState state, int alt, PredictionContext context) ATNConfig
(ATNState state, int alt, PredictionContext context, SemanticContext semanticContext) -
Method Summary
Modifier and TypeMethodDescriptionboolean
An ATN configuration is equal to another if both have the same state, they predict the same alternative, and syntactic/semantic contexts are the same.boolean
final int
This method gets the value of thereachesIntoOuterContext
field as it existed prior to the introduction of theisPrecedenceFilterSuppressed()
method.int
hashCode()
final boolean
final void
setPrecedenceFilterSuppressed
(boolean value) toString()
toString
(Recognizer<?, ?> recog, boolean showAlt)
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Field Details
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state
The ATN state associated with this configuration -
alt
public final int altWhat alt (or lexer rule) is predicted by this configuration -
context
The stack of invoking states leading to the rule/states associated with this config. We track only those contexts pushed during execution of the ATN simulator. -
reachesIntoOuterContext
public int reachesIntoOuterContextWe cannot execute predicates dependent upon local context unless we know for sure we are in the correct context. Because there is no way to do this efficiently, we simply cannot evaluate dependent predicates unless we are in the rule that initially invokes the ATN simulator.closure() tracks the depth of how far we dip into the outer context: depth > 0. Note that it may not be totally accurate depth since I don't ever decrement. TODO: make it a boolean then
For memory efficiency, the
isPrecedenceFilterSuppressed()
method is also backed by this field. Since the field is publicly accessible, the highest bit which would not cause the value to become negative is used to store this field. This choice minimizes the risk that code which only compares this value to 0 would be affected by the new purpose of the flag. It also ensures the performance of the existingATNConfig
constructors as well as certain operations likeATNConfigSet.add(ATNConfig, DoubleKeyMap)
method are completely unaffected by the change. -
semanticContext
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Constructor Details
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ATNConfig
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ATNConfig
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ATNConfig
public ATNConfig(ATNState state, int alt, PredictionContext context, SemanticContext semanticContext) -
ATNConfig
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ATNConfig
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ATNConfig
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ATNConfig
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ATNConfig
public ATNConfig(ATNConfig c, ATNState state, PredictionContext context, SemanticContext semanticContext)
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Method Details
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getOuterContextDepth
public final int getOuterContextDepth()This method gets the value of thereachesIntoOuterContext
field as it existed prior to the introduction of theisPrecedenceFilterSuppressed()
method. -
isPrecedenceFilterSuppressed
public final boolean isPrecedenceFilterSuppressed() -
setPrecedenceFilterSuppressed
public final void setPrecedenceFilterSuppressed(boolean value) -
equals
An ATN configuration is equal to another if both have the same state, they predict the same alternative, and syntactic/semantic contexts are the same. -
equals
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hashCode
public int hashCode() -
toString
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toString
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