/*
* JBoss, Home of Professional Open Source.
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/
package org.teiid.query.sql.symbol;
import org.teiid.query.sql.LanguageVisitor;
public class ExpressionSymbol extends Symbol implements DerivedExpression {
private Expression expression;
/**
* Construct an ExpressionSymbol with name and expression.
*/
public ExpressionSymbol(String name, Expression expression) {
super(name);
this.expression = expression;
}
/**
* Get the expression for this symbol
* @return Expression for this symbol
*/
public Expression getExpression() {
return this.expression;
}
/**
* Set the expression represented by this symbol.
* @param expression Expression for this expression symbol
*/
public void setExpression(Expression expression) {
this.expression = expression;
}
/**
* Get the type of the symbol
* @return Type of the symbol, may be null before resolution
*/
public Class getType() {
return this.expression.getType();
}
public void acceptVisitor(LanguageVisitor visitor) {
visitor.visit(this);
}
/**
* Return a deep copy of this object
* @return Deep copy of this object
*/
public Object clone() {
Expression clonedExpr = null;
if(getExpression() != null) {
clonedExpr = (Expression) getExpression().clone();
}
ExpressionSymbol copy = new ExpressionSymbol(getName(), clonedExpr);
return copy;
}
/**
* @see org.teiid.query.sql.symbol.Symbol#hashCode()
*/
public int hashCode() {
if (expression != null) {
return expression.hashCode();
}
return super.hashCode();
}
/**
* ExpressionSymbol matching is not based upon the name
*
* @see org.teiid.query.sql.symbol.Symbol#equals(java.lang.Object)
*/
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof ExpressionSymbol)) {
return false;
}
ExpressionSymbol exprSymbol = (ExpressionSymbol)obj;
if (expression == null ) {
return exprSymbol.getExpression() == null;
}
return expression.equals(exprSymbol.getExpression());
}
}