/*
* Copyright 2008 Fedora Commons
*
* 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.mulgara.sparql.parser.cst;
import java.util.List;
/**
* Absract class to provide basic functionality of an N-ary, associative operation.
*
* @created Feb 13, 2008
* @author Paula Gearon
* @copyright © 2008 <a href="http://www.fedora-commons.org/">Fedora Commons</a>
* @licence <a href="{@docRoot}/../LICENCE.txt">Apache License, Version 2.0</a>
*/
public abstract class AbstractNaryOperator<T extends Expression> implements Expression {
/** The list of expression operands */
protected List<T> operands;
/**
* @return the list of operands for this operation
*/
public List<T> getOperands() {
return operands;
}
/**
* @see org.mulgara.sparql.parser.cst.Node#getImage()
*/
public String getImage() {
StringBuffer result = new StringBuffer();
boolean first = true;
for (Expression e: operands) {
if (!first) result.append(" ").append(getOperatorString()).append(" ");
else first = false;
boolean bracket = e instanceof PrimaryExpression;
if (bracket) result.append("(");
result.append(e);
if (bracket) result.append(")");
}
return result.toString();
}
/**
* A string representation of the operator for this relation
* @return The operator as a string
*/
protected abstract String getOperatorString();
/**
* @see java.lang.Object#toString()
* @return By default this will return the image, since that's often right.
*/
public String toString() {
return getImage();
}
}