org.opencastproject.util.data.Iterators Maven / Gradle / Ivy
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* Licensed to The Apereo Foundation under one or more contributor license
* agreements. See the NOTICE file distributed with this work for additional
* information regarding copyright ownership.
*
*
* The Apereo Foundation licenses this file to you under the Educational
* Community License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of the License
* at:
*
* http://opensource.org/licenses/ecl2.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*
*/
package org.opencastproject.util.data;
import java.util.Iterator;
import java.util.NoSuchElementException;
public final class Iterators {
private Iterators() {
}
/** Integer range. Upper bound excluded. */
public static Iterator intRangeE(final int start, final int end) {
return new Iter() {
private int i = start;
@Override public boolean hasNext() {
return i < end;
}
@Override public Integer next() {
if (hasNext()) {
int r = i;
i++;
return r;
} else {
throw new NoSuchElementException();
}
}
};
}
/** An infinite stream of as. */
public static Iterator constant(final A a) {
return new Iter() {
@Override public boolean hasNext() {
return true;
}
@Override public A next() {
return a;
}
};
}
private abstract static class Iter implements Iterator {
@Override
public final void remove() {
throw new UnsupportedOperationException();
}
}
}