Package org.antlr.v4.runtime.atn

Class SemanticContext.Predicate

java.lang.Object

org.antlr.v4.runtime.atn.SemanticContext

org.antlr.v4.runtime.atn.SemanticContext.Predicate

Enclosing class:

SemanticContext

public static class SemanticContext.Predicate
extends SemanticContext

Nested Class Summary

Nested classes/interfaces inherited from class org.antlr.v4.runtime.atn.SemanticContext

SemanticContext.AND, SemanticContext.Empty, SemanticContext.Operator, SemanticContext.OR, SemanticContext.PrecedencePredicate, SemanticContext.Predicate

Field Summary

Fields

Modifier and Type	Field	Description
boolean	isCtxDependent
int	predIndex
int	ruleIndex

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Predicate()
	Predicate(int ruleIndex, int predIndex, boolean isCtxDependent)

Method Summary

Modifier and Type	Method	Description
boolean	equals(java.lang.Object obj)
boolean	eval(Recognizer<?,?> parser, RuleContext parserCallStack)	For context independent predicates, we evaluate them without a local context (i.e., null context).
int	hashCode()
java.lang.String	toString()

Methods inherited from class org.antlr.v4.runtime.atn.SemanticContext

and, evalPrecedence, or

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

ruleIndex

public final int ruleIndex

predIndex

public final int predIndex

isCtxDependent

public final boolean isCtxDependent

Constructor Detail

Predicate

protected Predicate()

Predicate

public Predicate(int ruleIndex,
                 int predIndex,
                 boolean isCtxDependent)

Method Detail

eval

public boolean eval(Recognizer<?,?> parser,
                    RuleContext parserCallStack)

Description copied from class: SemanticContext

For context independent predicates, we evaluate them without a local context (i.e., null context). That way, we can evaluate them without having to create proper rule-specific context during prediction (as opposed to the parser, which creates them naturally). In a practical sense, this avoids a cast exception from RuleContext to myruleContext.

For context dependent predicates, we must pass in a local context so that references such as $arg evaluate properly as _localctx.arg. We only capture context dependent predicates in the context in which we begin prediction, so we passed in the outer context here in case of context dependent predicate evaluation.

Specified by:

eval in class SemanticContext

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object