65 lines
1.8 KiB
Java
65 lines
1.8 KiB
Java
/*******************************************************************************
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* Copyright (c) 2002 - 2006 IBM Corporation.
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* All rights reserved. This program and the accompanying materials
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* are made available under the terms of the Eclipse Public License v1.0
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* which accompanies this distribution, and is available at
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* http://www.eclipse.org/legal/epl-v10.html
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*
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* Contributors:
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* IBM Corporation - initial API and implementation
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*******************************************************************************/
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package com.ibm.wala.util.collections;
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import java.util.Iterator;
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import com.ibm.wala.util.Predicate;
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import com.ibm.wala.util.functions.Function;
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/**
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* utilities dealing with Iterators
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*/
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public class IteratorUtil {
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/**
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* @return true iff the Iterator returns some elements which equals() the object o
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*/
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public static <T> boolean contains(Iterator<? extends T> it, T o) {
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if (it == null) {
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throw new IllegalArgumentException("null it");
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}
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while (it.hasNext()) {
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if (o.equals(it.next())) {
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return true;
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}
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}
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return false;
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}
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public final static <T> int count(Iterator<T> it) throws IllegalArgumentException {
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if (it == null) {
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throw new IllegalArgumentException("it == null");
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}
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int count = 0;
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while (it.hasNext()) {
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it.next();
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count++;
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}
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return count;
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}
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public static <T, S extends T> Iterator<S> filter(Iterator<T> iterator, final Class<S> cls) {
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return new MapIterator<>(
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new FilterIterator<T>(iterator, new Predicate<T>() {
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@Override public boolean test(T o) {
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return cls.isInstance(o);
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}
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}),
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new Function<T,S>() {
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@SuppressWarnings("unchecked")
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@Override
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public S apply(T object) {
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return (S) object;
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}
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});
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}
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}
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