/*
* 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 java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.teiid.query.QueryPlugin;
import org.teiid.query.sql.LanguageVisitor;
public class CaseExpression extends AbstractCaseExpression {
/**
* The expression whose evaluation is being tested in this case expression.
*/
private Expression expression = null;
/**
* Ordered List of Expressions in the WHEN parts of this expression.
*/
private List when = null;
/**
* Constructor for CaseExpression objects
* @param expression a non-null expression
* @param when a non-null List containing at least one Expression
* @param then a non-null List containing at least one Expression
*/
public CaseExpression(Expression expression, List when, List then) {
setExpression(expression);
setWhen(when, then);
}
/**
* Gets the expression whose evaluation is being tested in this case expression.
* @return
*/
public Expression getExpression() {
return expression;
}
/**
* Sets the expression for this case expression
* @param expr a non-null Expression
*/
public void setExpression(Expression expr) {
if (expr == null) {
throw new IllegalArgumentException(QueryPlugin.Util.getString("ERR.015.010.0035")); //$NON-NLS-1$
}
this.expression = expr;
}
/**
*
* @see org.teiid.query.sql.symbol.AbstractCaseExpression#getWhenCount()
*/
public int getWhenCount() {
return (when == null) ? 0 : when.size();
}
/**
* Gets the List of Expressions in the WHEN parts of this expression. Never null.
* @return
*/
public List getWhen() {
return when;
}
/**
* Gets the WHEN expression at the given 0-based index.
* @param index
* @return
*/
public Expression getWhenExpression(int index) {
return (Expression)when.get(index);
}
/**
* Sets the WHEN and THEN parts of this CASE expression.
* Both lists should have the same number of Expressions.
* @param when a non-null List of at least one Expression
* @param then a non-null List of at least one Expression
*/
public void setWhen(List when, List then) {
if (when == null || then == null) {
throw new IllegalArgumentException(QueryPlugin.Util.getString("ERR.015.010.0036")); //$NON-NLS-1$
}
if (when.size() != then.size() ||
when.size() < 1) {
throw new IllegalArgumentException(QueryPlugin.Util.getString("ERR.015.010.0036")); //$NON-NLS-1$
}
for (int i = 0 ; i < when.size(); i++) {
if (!(when.get(i) instanceof Expression)) {
throw new IllegalArgumentException(QueryPlugin.Util.getString("ERR.015.010.0037")); //$NON-NLS-1$
}
if (!(then.get(i) instanceof Expression)) {
throw new IllegalArgumentException(QueryPlugin.Util.getString("ERR.015.010.0038")); //$NON-NLS-1$
}
}
if (this.when != when) {
this.when = Collections.unmodifiableList(when);
}
setThen(then);
}
public void acceptVisitor(LanguageVisitor visitor) {
visitor.visit(this);
}
/**
* @see java.lang.Object#clone()
*/
public Object clone() {
Expression expr = (Expression)expression.clone();
int whenCount = getWhenCount();
ArrayList whenCopy = new ArrayList(whenCount);
ArrayList thenCopy = new ArrayList(whenCount);
for(int i = 0; i < whenCount; i++) {
whenCopy.add(getWhenExpression(i).clone());
thenCopy.add(getThenExpression(i).clone());
}
Expression elseExpr = getElseExpression();
if (elseExpr != null) {
elseExpr = (Expression)elseExpr.clone();
}
CaseExpression copy = new CaseExpression(expr, whenCopy, thenCopy);
copy.setType(getType());
copy.setElseExpression(elseExpr);
return copy;
}
public boolean equals(Object obj) {
if (!super.equals(obj)) return false;
if (!(obj instanceof CaseExpression)) return false;
CaseExpression other = (CaseExpression)obj;
return getExpression().equals(other.getExpression()) &&
when.equals(other.when);
}
}