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 * modification, are permitted provided that the following conditions are
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 *
 * Redistributions of source code must retain the above copyright
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package com.android.tools.smali.util;

import java.lang.Iterable;
import java.util.Iterator;

/**
 * Combines two iterators into a single iterator. The returned iterator iterates across the elements
 * in {@code a}, followed by the elements in {@code b}. The source iterators are not polled until
 * necessary.
 * <p>
 * The returned iterator does not support {@code remove()}.
 */
public class ChainedIterator<T extends Object> implements Iterator<T>, Iterable<T> {
    Iterator<T> iteratorA;
    Iterator<T> iteratorB;

    public ChainedIterator(Iterable<T> iterableA, Iterable<T> iterableB) {
        this.iteratorA = iterableA.iterator();
        this.iteratorB = iterableB.iterator();
    }

    public ChainedIterator(Iterator<T> iteratorA, Iterator<T> iteratorB) {
        this.iteratorA = iteratorA;
        this.iteratorB = iteratorB;
    }

    @Override
    public final boolean hasNext() {
        return iteratorA.hasNext() || iteratorB.hasNext();
    }

    @Override
    public final T next() {
        if (iteratorA.hasNext()) {
            return iteratorA.next();
        }
        return iteratorB.next();
    }

    @Override
    public final void remove() {
        throw new UnsupportedOperationException();
    }

    @Override
    public final Iterator<T> iterator() {
        return this;
    }
}