| /* |
| * Copyright 2009-2010 by The Regents of the University of California |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * you may obtain a copy of the License from |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package edu.uci.ics.hyracks.algebricks.core.algebra.expressions; |
| |
| import java.util.Collection; |
| import java.util.List; |
| |
| import org.apache.commons.lang3.mutable.Mutable; |
| |
| import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalExpressionTag; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.visitors.ILogicalExpressionVisitor; |
| |
| public class VariableReferenceExpression extends AbstractLogicalExpression { |
| private int tupleRef; |
| private LogicalVariable variable; |
| |
| public VariableReferenceExpression(int tupleRef, LogicalVariable variable) { |
| this.tupleRef = tupleRef; |
| this.variable = variable; |
| } |
| |
| public VariableReferenceExpression(LogicalVariable variable) { |
| this(0, variable); |
| } |
| |
| public int getTupleRef() { |
| return tupleRef; |
| } |
| |
| public void setTupleRef(int tupleRef) { |
| this.tupleRef = tupleRef; |
| } |
| |
| public LogicalVariable getVariableReference() { |
| return variable; |
| } |
| |
| public void setVariable(LogicalVariable variable) { |
| this.variable = variable; |
| } |
| |
| @Override |
| public LogicalExpressionTag getExpressionTag() { |
| return LogicalExpressionTag.VARIABLE; |
| } |
| |
| @Override |
| public String toString() { |
| return "%" + tupleRef + "->" + variable.toString(); |
| } |
| |
| @Override |
| public void getUsedVariables(Collection<LogicalVariable> vars) { |
| // if (!vars.contains(variable)) { |
| vars.add(variable); |
| // } |
| } |
| |
| @Override |
| public void substituteVar(LogicalVariable v1, LogicalVariable v2) { |
| if (variable.equals(v1)) { |
| variable = v2; |
| } |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (!(obj instanceof VariableReferenceExpression)) { |
| return false; |
| } else { |
| return tupleRef == ((VariableReferenceExpression) obj).tupleRef |
| && variable.equals(((VariableReferenceExpression) obj).getVariableReference()); |
| } |
| } |
| |
| @Override |
| public int hashCode() { |
| return tupleRef + variable.getId(); |
| } |
| |
| @Override |
| public <R, T> R accept(ILogicalExpressionVisitor<R, T> visitor, T arg) throws AlgebricksException { |
| return visitor.visitVariableReferenceExpression(this, arg); |
| } |
| |
| @Override |
| public AbstractLogicalExpression cloneExpression() { |
| return new VariableReferenceExpression(variable); |
| } |
| |
| @Override |
| public boolean splitIntoConjuncts(List<Mutable<ILogicalExpression>> conjs) { |
| return false; |
| } |
| } |