drv.AbstractIterator.drv Maven / Gradle / Ivy
/*
* Copyright (C) 2002-2017 Sebastiano Vigna
*
* Licensed under the Apache 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://www.apache.org/licenses/LICENSE-2.0
*
* 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 PACKAGE;
/** An abstract class facilitating the creation of type-specific iterators.
*
* To create a type-specific iterator you need both a method returning the
* next element as primitive type and a method returning the next element as an
* object. However, if you inherit from this class you need just one (anyone).
*
*
This class implements also a trivial version of {@link #skip(int)} that uses
* type-specific methods; moreover, {@link #remove()} will throw an {@link
* UnsupportedOperationException}.
*
* @see java.util.Iterator
*/
public abstract class KEY_ABSTRACT_ITERATOR KEY_GENERIC implements KEY_ITERATOR KEY_GENERIC {
protected KEY_ABSTRACT_ITERATOR() {}
#if KEYS_PRIMITIVE
/** {@inheritDoc}
*
This implementation delegates to the corresponding generic method. */
@Override
public KEY_TYPE NEXT_KEY() {
return next().KEY_VALUE();
}
/** {@inheritDoc}
*
This implementation delegates to the corresponding type-specific method.
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
public KEY_GENERIC_CLASS next() {
return KEY_CLASS.valueOf(NEXT_KEY());
}
#endif
/** {@inheritDoc}
*
This implementation always throws an {@link UnsupportedOperationException}. */
@Override
public void remove() {
throw new UnsupportedOperationException();
}
/** {@inheritDoc}
*
This implementaion iterates the type-specific version of {@link #next()} for at most
* {@code n} times, stopping if {@link #hasNext()} becomes false.
*
* @param n the number of elements to skip.
* @return the number of elements actually skipped.
*/
@Override
public int skip(final int n) {
int i = n;
while(i-- != 0 && hasNext()) NEXT_KEY();
return n - i - 1;
}
}