jlibs.core.graph.sequences.RepeatSequence Maven / Gradle / Ivy
/**
* Copyright 2015 Santhosh Kumar Tekuri
*
* The JLibs authors license 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.
*/
package jlibs.core.graph.sequences;
import jlibs.core.graph.Sequence;
/**
* A Sequence that can repeat given sequence specified number of
* times
*
* @author Santhosh Kumar T
*/
public class RepeatSequence extends AbstractSequence{
private Sequence sequence;
private int count;
public RepeatSequence(Sequence sequence, int count){
if(count<0)
throw new IllegalArgumentException(String.format("can't repeat %d times", count));
this.sequence = sequence;
this.count = count;
}
/*-------------------------------------------------[ Advancing ]---------------------------------------------------*/
private int pos;
@Override
protected E findNext(){
if(pos==count)
return null;
while(true){
E next = sequence.next();
if(next==null){
pos++;
if(pos==count)
return null;
sequence = sequence.copy();
}else
return next;
}
}
/*-------------------------------------------------[ Reuse ]---------------------------------------------------*/
@Override
public void reset(){
super.reset();
_reset();
}
private void _reset(){
sequence = sequence.copy();
pos = 0;
}
@Override
public RepeatSequence copy(){
return new RepeatSequence(sequence.copy(), count);
}
/*-------------------------------------------------[ Optimization ]---------------------------------------------------*/
@Override
public int length(){
return sequence.length() * count;
}
}