/*
 * Copyright 2020-2022 Equinix, Inc
 * Copyright 2014-2022 The Billing Project, LLC
 *
 * The Billing Project licenses 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 org.killbill.commons.utils.collect;

import java.util.Iterator;

import org.killbill.commons.utils.Preconditions;

abstract class TransformedIterator<F, T> implements Iterator<T> {
    final Iterator<? extends F> backingIterator;

    TransformedIterator(final Iterator<? extends F> backingIterator) {
        this.backingIterator = Preconditions.checkNotNull(backingIterator);
    }

    abstract T transform(F from);

    @Override
    public final boolean hasNext() {
        return backingIterator.hasNext();
    }

    @Override
    public final T next() {
        return transform(backingIterator.next());
    }

    @Override
    public final void remove() {
        backingIterator.remove();
    }
}
