org.antlr.v4.runtime.atn.PredicateTransition Maven / Gradle / Ivy
/*
* 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.
*/
package org.antlr.v4.runtime.atn;
/** TODO: this is old comment:
* A tree of semantic predicates from the grammar AST if label==SEMPRED.
* In the ATN, labels will always be exactly one predicate, but the DFA
* may have to combine a bunch of them as it collects predicates from
* multiple ATN configurations into a single DFA state.
*/
public final class PredicateTransition extends AbstractPredicateTransition {
public final int ruleIndex;
public final int predIndex;
public final boolean isCtxDependent; // e.g., $i ref in pred
public PredicateTransition(ATNState target, int ruleIndex, int predIndex, boolean isCtxDependent) {
super(target);
this.ruleIndex = ruleIndex;
this.predIndex = predIndex;
this.isCtxDependent = isCtxDependent;
}
@Override
public int getSerializationType() {
return PREDICATE;
}
@Override
public boolean isEpsilon() { return true; }
@Override
public boolean matches(int symbol, int minVocabSymbol, int maxVocabSymbol) {
return false;
}
public SemanticContext.Predicate getPredicate() {
return new SemanticContext.Predicate(ruleIndex, predIndex, isCtxDependent);
}
@Override
public String toString() {
return "pred_"+ruleIndex+":"+predIndex;
}
}