/*
* Janino - An embedded Java[TM] compiler
*
* Copyright (c) 2001-2010, Arno Unkrig
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
* following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the
* following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
package org.codehaus.janino.util;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.NoSuchElementException;
import org.codehaus.janino.JaninoRuntimeException;
/**
* An {@link java.util.Iterator} that traverses a {@link java.util.Collection} of
* {@link java.util.Iterator}s.
*/
public class MultiIterator implements Iterator {
private static final Iterator AT_END = new Iterator() {
public boolean hasNext() { return false; }
public Object next() { throw new NoSuchElementException(); }
public void remove() { throw new UnsupportedOperationException(); }
};
private final Iterator outer; // Over Iterators, Collections or arrays
private Iterator inner = MultiIterator.AT_END;
/**
* @param iterators An array of {@link Iterator}s
*/
public MultiIterator(Iterator[] iterators) {
this.outer = Arrays.asList(iterators).iterator();
}
/**
* @param collections An array of {@link Collection}s
*/
public MultiIterator(Collection[] collections) {
this.outer = Arrays.asList(collections).iterator();
}
/**
* @param arrays An array of arrays
*/
public MultiIterator(Object[][] arrays) {
this.outer = Arrays.asList(arrays).iterator();
}
/**
* @param collection A {@link Collection} of {@link Collection}s, {@link Iterator}s and/or arrays
*/
public MultiIterator(Collection collection) {
this.outer = collection.iterator();
}
/**
* @param iterator An iterator over {@link Collection}s, {@link Iterator}s and/or arrays
*/
public MultiIterator(Iterator iterator) {
this.outer = iterator;
}
/**
* @param array An array of {@link Collection}s, {@link Iterator}s and/or arrays
*/
public MultiIterator(Object[] array) {
this.outer = Arrays.asList(array).iterator();
}
/**
* Iterates over the given {@link Collection}, prepended with the given {@link Object}.
*/
public MultiIterator(Object object, Collection collection) {
this.outer = Arrays.asList(new Object[] {
new Object[] { object },
collection
}).iterator();
}
/**
* Iterates over the given {@link Collection}, appended with the given {@link Object}.
*/
public MultiIterator(Collection collection, Object object) {
this.outer = Arrays.asList(new Object[] {
collection,
new Object[] { object }
}).iterator();
}
/**
* Iterates over the given {@link Iterator}, prepended with the given <code>prefix</code>.
*/
public MultiIterator(Object prefix, Iterator iterator) {
this.outer = Arrays.asList(new Object[] {
new Object[] { prefix },
iterator
}).iterator();
}
/**
* Iterates over the given {@link Iterator}, appended with the given <code>suffix</code>.
*/
public MultiIterator(Iterator iterator, Object suffix) {
this.outer = Arrays.asList(new Object[] {
iterator,
new Object[] { suffix }
}).iterator();
}
public boolean hasNext() {
for (;;) {
if (this.inner.hasNext()) return true;
if (!this.outer.hasNext()) return false;
Object o = this.outer.next();
if (o instanceof Iterator) {
this.inner = (Iterator) o;
} else
if (o instanceof Collection) {
this.inner = ((Collection) o).iterator();
} else
if (o instanceof Object[]) {
this.inner = Arrays.asList((Object[]) o).iterator();
} else
{
throw new JaninoRuntimeException("Unexpected element type \"" + o.getClass().getName() + "\"");
}
}
}
public Object next() {
if (this.hasNext()) return this.inner.next();
throw new NoSuchElementException();
}
public void remove() {
this.inner.remove();
}
}