package org.apache.velocity.runtime.parser.node;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
import java.util.ArrayList;
import java.util.List;
import org.apache.velocity.context.InternalContextAdapter;
import org.apache.velocity.exception.MethodInvocationException;
import org.apache.velocity.runtime.log.Log;
import org.apache.velocity.runtime.parser.Parser;
/**
* handles the range 'operator' [ n .. m ]
*
* Please look at the Parser.jjt file which is
* what controls the generation of this class.
*
* @author <a href="mailto:[email protected]">Geir Magnusson Jr.</a>
*/
public class ASTIntegerRange extends SimpleNode
{
/**
* @param id
*/
public ASTIntegerRange(int id)
{
super(id);
}
/**
* @param p
* @param id
*/
public ASTIntegerRange(Parser p, int id)
{
super(p, id);
}
/**
* @see org.apache.velocity.runtime.parser.node.SimpleNode#jjtAccept(org.apache.velocity.runtime.parser.node.ParserVisitor, java.lang.Object)
*/
public Object jjtAccept(ParserVisitor visitor, Object data)
{
return visitor.visit(this, data);
}
/**
* does the real work. Creates an Vector of Integers with the
* right value range
*
* @param context app context used if Left or Right of .. is a ref
* @return Object array of Integers
* @throws MethodInvocationException
*/
public Object value( InternalContextAdapter context)
throws MethodInvocationException
{
/*
* get the two range ends
*/
Object left = jjtGetChild(0).value( context );
Object right = jjtGetChild(1).value( context );
/*
* if either is null, lets log and bail
*/
if (left == null || right == null)
{
log.error((left == null ? "Left" : "Right")
+ " side of range operator [n..m] has null value."
+ " Operation not possible. "
+ Log.formatFileString(this));
return null;
}
/*
* if not a Number, not much we can do either
*/
if ( !( left instanceof Number ) || !( right instanceof Number ))
{
log.error((!(left instanceof Number) ? "Left" : "Right")
+ " side of range operator is not a valid type. "
+ "Currently only integers (1,2,3...) and the Number type are supported. "
+ Log.formatFileString(this));
return null;
}
/*
* get the two integer values of the ends of the range
*/
int l = ((Number) left).intValue() ;
int r = ((Number) right).intValue();
/*
* find out how many there are
*/
int nbrElements = Math.abs( l - r );
nbrElements += 1;
/*
* Determine whether the increment is positive or negative.
*/
int delta = ( l >= r ) ? -1 : 1;
/*
* Fill the range with the appropriate values.
*/
List elements = new ArrayList(nbrElements);
int value = l;
for (int i = 0; i < nbrElements; i++)
{
// TODO: JDK 1.4+ -> valueOf()
elements.add(new Integer(value));
value += delta;
}
return elements;
}
}
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