package com.planet_ink.coffee_mud.core.collections;
import java.util.Collection;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.NoSuchElementException;
import java.util.Vector;
/*
Copyright 2010-2016 Bo Zimmerman
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.
*/
public class MultiIterator<K> implements Iterator<K>
{
private final LinkedList<Iterator<K>> iters=new LinkedList<Iterator<K>>();
private volatile Iterator<K> iter=null;
public MultiIterator(Iterator<K>[] esets)
{
if((esets==null)||(esets.length==0))
return;
for(final Iterator<K> I : esets)
iters.add(I);
}
public MultiIterator(Collection<Iterator<K>> esets)
{
if((esets==null)||(esets.size()==0))
return;
iters.addAll(esets);
for(final Iterator<K> I : esets)
iters.add(I);
}
public MultiIterator(Iterable<K>[] esets)
{
if((esets==null)||(esets.length==0))
return;
for(final Iterable<K> I : esets)
iters.add(I.iterator());
}
public MultiIterator(Iterable<? extends Iterable<K>> esets)
{
if(esets==null)
return;
for(final Iterable<K> I : esets)
iters.add(I.iterator());
}
public MultiIterator()
{
}
public void add(Iterator<K> eset)
{
iters.add(eset);
}
@Override
public boolean hasNext()
{
boolean hasNext = (iter != null) && iter.hasNext();
while(!hasNext)
{
if(iters.size()==0)
{
iter=null;
return false;
}
iter=iters.removeFirst();
hasNext = (iter != null) && iter.hasNext();
}
return hasNext;
}
@Override
public K next()
{
if(!hasNext())
throw new NoSuchElementException();
return iter.next();
}
@Override
public void remove()
{
if(iter != null)
iter.remove();
}
}
