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/*
* [The "BSD license"]
* Copyright (c) 2010 Terence Parr
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.antlr.analysis;
import org.antlr.tool.Grammar;
import org.antlr.tool.GrammarAST;
public class PredicateLabel extends Label {
/** A tree of semantic predicates from the grammar AST if label==SEMPRED.
* In the NFA, labels will always be exactly one predicate, but the DFA
* may have to combine a bunch of them as it collects predicates from
* multiple NFA configurations into a single DFA state.
*/
protected SemanticContext semanticContext;
/** Make a semantic predicate label */
public PredicateLabel(GrammarAST predicateASTNode) {
super(SEMPRED);
this.semanticContext = new SemanticContext.Predicate(predicateASTNode);
}
/** Make a semantic predicates label */
public PredicateLabel(SemanticContext semCtx) {
super(SEMPRED);
this.semanticContext = semCtx;
}
public int hashCode() {
return semanticContext.hashCode();
}
public boolean equals(Object o) {
if ( o==null ) {
return false;
}
if ( this == o ) {
return true; // equals if same object
}
if ( !(o instanceof PredicateLabel) ) {
return false;
}
return semanticContext.equals(((PredicateLabel)o).semanticContext);
}
public boolean isSemanticPredicate() {
return true;
}
public SemanticContext getSemanticContext() {
return semanticContext;
}
public String toString() {
return "{"+semanticContext+"}?";
}
public String toString(Grammar g) {
return toString();
}
}
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