/*
* Copyright 2008 Udai Gupta, Ralf Joachim
*
* 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 at
*
* 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 org.castor.cpa.query.object.function;
import java.math.BigDecimal;
import org.castor.cpa.query.Expression;
import org.castor.cpa.query.object.literal.BigDecimalLiteral;
import org.castor.cpa.query.object.literal.DoubleLiteral;
import org.castor.cpa.query.object.literal.LongLiteral;
/**
* Final class that represents LOCATE function.
*
* @author <a href="mailto:mailtoud AT gmail DOT com">Udai Gupta</a>
* @author <a href="mailto:ralf DOT joachim AT syscon DOT eu">Ralf Joachim</a>
* @version $Revision: 7121 $ $Date: 2006-04-25 16:09:10 -0600 (Tue, 25 Apr 2006) $
* @since 1.3
*/
public final class Locate extends AbstractFunction {
//--------------------------------------------------------------------------
/** Maximum offset when comparing double and BigDecimal values. */
private static final double OFFSET = 1E-10;
//--------------------------------------------------------------------------
/** The string expression to be searched in by LOCATE function. */
private Expression _string;
/** The value expression to search for by LOCATE function. */
private Expression _value;
/** The index expression defining the start position of LOCATE function. */
private Expression _index;
//--------------------------------------------------------------------------
/**
* Construct an instance of Locate function with default start position.
*/
public Locate() {
_index = new LongLiteral(1);
}
//--------------------------------------------------------------------------
/**
* Gets the string expression to be searched in by LOCATE function.
*
* @return The string expression to be searched in by LOCATE function.
*/
public Expression getString() {
return _string;
}
/**
* Sets the string expression to be searched in by LOCATE function.
*
* @param string The new string expression to be searched in by LOCATE function.
*/
public void setString(final Expression string) {
_string = string;
}
/**
* Gets the expression to search for by LOCATE function.
*
* @return The expression to search for by LOCATE function.
*/
public Expression getValue() {
return _value;
}
/**
* Sets the expression to search for by LOCATE function.
*
* @param value The new expression to search for by LOCATE function.
*/
public void setValue(final Expression value) {
_value = value;
}
/**
* Gets the expression defining the start position of LOCATE function.
*
* @return The expression defining the start position of LOCATE function.
*/
public Expression getIndex() {
return _index;
}
/**
* Sets the expression defining the start position of LOCATE function.
*
* @param index The new expression defining the start position of LOCATE function.
*/
public void setIndex(final Expression index) {
_index = index;
}
//--------------------------------------------------------------------------
/**
* {@inheritDoc}
*/
public StringBuilder toString(final StringBuilder sb) {
boolean defaultStart = false;
if (_index instanceof LongLiteral) {
LongLiteral literal = (LongLiteral) _index;
defaultStart = (literal.getValue() == 1);
} else if (_index instanceof DoubleLiteral) {
DoubleLiteral literal = (DoubleLiteral) _index;
defaultStart = (Math.abs(literal.getValue() - 1.0) < OFFSET);
} else if (_index instanceof BigDecimalLiteral) {
BigDecimalLiteral literal = (BigDecimalLiteral) _index;
BigDecimal value = literal.getValue();
BigDecimal diff = value.subtract(new BigDecimal(1.0)).abs();
defaultStart = (diff.compareTo(new BigDecimal(OFFSET)) < 0);
}
sb.append("LOCATE(");
if (_string != null) { _string.toString(sb); }
sb.append(", ");
if (_value != null) { _value.toString(sb); }
if (!defaultStart) {
sb.append(", ");
if (_index != null) { _index.toString(sb); }
}
return sb.append(')');
}
//--------------------------------------------------------------------------
}