jlibs.core.graph.sequences.EmptySequence 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;
/**
* @author Santhosh Kumar T
*/
public final class EmptySequence implements Sequence{
private static final EmptySequence INSTANCE = new EmptySequence();
@SuppressWarnings("unchecked")
public static EmptySequence getInstance(){
return (EmptySequence)INSTANCE;
}
private EmptySequence(){}
/*-------------------------------------------------[ Advancing ]---------------------------------------------------*/
@Override
public boolean hasNext(){
return false;
}
@Override
public E next(){
return null;
}
@Override
public E next(int count){
return null;
}
/*-------------------------------------------------[ Query ]---------------------------------------------------*/
@Override
public int index(){
return 0;
}
@Override
public E current(){
return null;
}
@Override
public int length(){
return 0;
}
/*-------------------------------------------------[ Reuse ]---------------------------------------------------*/
@Override
public void reset(){}
@Override
public EmptySequence copy(){
return this;
}
}