/*
* Copyright 2015 Goldman Sachs.
*
* 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 com.gs.collections.impl.lazy.iterator;
import java.util.Iterator;
import java.util.NoSuchElementException;
import com.gs.collections.api.RichIterable;
import com.gs.collections.api.block.function.Function0;
import com.gs.collections.api.collection.MutableCollection;
import com.gs.collections.impl.factory.Lists;
import net.jcip.annotations.Immutable;
@Immutable
public final class ChunkIterator<T>
implements Iterator<RichIterable<T>>
{
private final Iterator<T> iterator;
private final int size;
private final Function0<MutableCollection<T>> speciesNewStrategy;
public ChunkIterator(final Iterable<T> iterable, int size)
{
if (size <= 0)
{
throw new IllegalArgumentException("Size for groups must be positive but was: " + size);
}
this.size = size;
this.iterator = iterable.iterator();
if (iterable instanceof MutableCollection)
{
this.speciesNewStrategy = new Function0<MutableCollection<T>>()
{
public MutableCollection<T> value()
{
return ((MutableCollection<T>) iterable).newEmpty();
}
};
}
else
{
this.speciesNewStrategy = new Function0<MutableCollection<T>>()
{
public MutableCollection<T> value()
{
return Lists.mutable.empty();
}
};
}
}
public void remove()
{
throw new UnsupportedOperationException("Cannot call remove() on " + this.getClass().getSimpleName());
}
public boolean hasNext()
{
return this.iterator.hasNext();
}
public RichIterable<T> next()
{
if (!this.iterator.hasNext())
{
throw new NoSuchElementException();
}
int i = this.size;
MutableCollection<T> result = this.speciesNewStrategy.value();
while (i > 0 && this.iterator.hasNext())
{
result.add(this.iterator.next());
i -= 1;
}
return result;
}
}