tapestry-func/src/main/java/org/apache/tapestry5/func/LazyIterator.java

// Copyright 2010, 2011 The Apache Software Foundation
//
// 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 org.apache.tapestry5.func;

import java.util.Iterator;

/**
 * Converts an {@link Iterator} into a {@link LazyFunction}.
 */
class LazyIterator<T> implements LazyFunction<T>
{
    private final Iterator<T> iterator;

    public LazyIterator(Iterator<T> iterator)
    {
        assert iterator != null;

        this.iterator = iterator;
    }

    @Override
    public LazyContinuation<T> next()
    {
        if (!iterator.hasNext())
            return null;

        return new LazyContinuation<T>(iterator.next(), this);
    }
}