50 lines
1.3 KiB
Java
50 lines
1.3 KiB
Java
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/*
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* The Broad Institute
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* SOFTWARE COPYRIGHT NOTICE AGREEMENT
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* This software and its documentation are copyright 2009 by the
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* Broad Institute/Massachusetts Institute of Technology. All rights are reserved.
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*
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* This software is supplied without any warranty or guaranteed support whatsoever. Neither
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* the Broad Institute nor MIT can be responsible for its use, misuse, or functionality.
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*/
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package edu.mit.broad.sam.util;
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import java.util.Iterator;
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public class PeekIterator<T> implements Iterator<T> {
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Iterator<T> underlyingIterator;
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T peekedElement = null;
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public PeekIterator(final Iterator<T> underlyingIterator) {
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this.underlyingIterator = underlyingIterator;
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}
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public boolean hasNext() {
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return peekedElement != null || underlyingIterator.hasNext();
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}
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public T next() {
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if (peekedElement != null) {
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final T ret = peekedElement;
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peekedElement = null;
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return ret;
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}
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return underlyingIterator.next();
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}
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public T peek() {
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if (peekedElement == null) {
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peekedElement = underlyingIterator.next();
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}
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return peekedElement;
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}
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public void remove() {
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throw new UnsupportedOperationException();
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}
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public Iterator<T> getUnderlyingIterator() {
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return underlyingIterator;
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}
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}
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