86 lines
2.8 KiB
Java
86 lines
2.8 KiB
Java
/*
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[The "BSD licence"]
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Copyright (c) 2005-2008 Terence Parr
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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1. Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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3. The name of the author may not be used to endorse or promote products
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derived from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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package org.antlr.analysis;
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import org.antlr.tool.GrammarAST;
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import org.antlr.tool.Grammar;
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public class PredicateLabel extends Label {
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/** A tree of semantic predicates from the grammar AST if label==SEMPRED.
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* In the NFA, labels will always be exactly one predicate, but the DFA
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* may have to combine a bunch of them as it collects predicates from
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* multiple NFA configurations into a single DFA state.
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*/
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protected SemanticContext semanticContext;
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/** Make a semantic predicate label */
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public PredicateLabel(GrammarAST predicateASTNode) {
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super(SEMPRED);
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this.semanticContext = new SemanticContext.Predicate(predicateASTNode);
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}
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/** Make a semantic predicates label */
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public PredicateLabel(SemanticContext semCtx) {
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super(SEMPRED);
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this.semanticContext = semCtx;
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}
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public int hashCode() {
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return semanticContext.hashCode();
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}
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public boolean equals(Object o) {
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if ( o==null ) {
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return false;
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}
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if ( this == o ) {
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return true; // equals if same object
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}
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if ( !(o instanceof PredicateLabel) ) {
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return false;
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}
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return semanticContext.equals(((PredicateLabel)o).semanticContext);
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}
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public boolean isSemanticPredicate() {
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return true;
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}
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public SemanticContext getSemanticContext() {
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return semanticContext;
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}
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public String toString() {
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return "{"+semanticContext+"}?";
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}
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public String toString(Grammar g) {
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return toString();
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}
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}
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