59 lines
879 B
Java
59 lines
879 B
Java
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package net.sourceforge.tuned;
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import java.util.Iterator;
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public abstract class FilterIterator<S, T> implements Iterator<T> {
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private final Iterator<S> sourceIterator;
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public FilterIterator(Iterable<S> source) {
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this(source.iterator());
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}
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public FilterIterator(Iterator<S> sourceIterator) {
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this.sourceIterator = sourceIterator;
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}
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@Override
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public boolean hasNext() {
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return peekNext(false) != null;
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}
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@Override
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public T next() {
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try {
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return peekNext(true);
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} finally {
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current = null;
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}
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}
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private T current = null;
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private T peekNext(boolean forceNext) {
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while (current == null && (forceNext || (sourceIterator.hasNext()))) {
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current = filter(sourceIterator.next());
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}
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return current;
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}
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protected abstract T filter(S sourceValue);
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@Override
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public void remove() {
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sourceIterator.remove();
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}
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}
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