package de.lmu.ifi.dbs.elki.utilities.datastructures.arraylike;
/*
This file is part of ELKI:
Environment for Developing KDD-Applications Supported by Index-Structures
Copyright (C) 2013
Ludwig-Maximilians-Universität München
Lehr- und Forschungseinheit für Datenbanksysteme
ELKI Development Team
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see .
*/
/**
* Class to extend an array with a single element virtually.
*
* @author Erich Schubert
*
* @param Object type
*/
public class ExtendedArray implements ArrayAdapter> {
/**
* The array
*/
final Object array;
/**
* The array adapter
*/
final ArrayAdapter getter;
/**
* The extra element
*/
final T extra;
/**
* Our size
*/
final int size;
/**
* Constructor.
*
* @param array Original array
* @param getter Adapter for array
* @param extra Extra element
*/
protected ExtendedArray(Object array, ArrayAdapter getter, T extra) {
super();
this.array = array;
this.getter = getter;
this.extra = extra;
this.size = getter.size(array) + 1;
}
@Override
public int size(ExtendedArray array) {
assert (this == array);
return size;
}
@Override
public T get(ExtendedArray array, int off) throws IndexOutOfBoundsException {
assert (this == array);
if(off == size - 1) {
return extra;
}
return getter.get(this.array, off);
}
/**
* Static wrapper that has a nicer generics signature.
*
* @param array Array to extend
* @param getter Getter for array
* @param extra Extra element
* @return Extended array
*/
@SuppressWarnings("unchecked")
public static ExtendedArray extend(A array, ArrayAdapter getter, T extra) {
return new ExtendedArray<>(array, (ArrayAdapter) getter, extra);
}
}