/**
  * Copyright (c): Uwe Schmidt, FH Wedel
  *
  * You may study, modify and distribute this source code
  * FOR NON-COMMERCIAL PURPOSES ONLY.
  * This copyright message has to remain unchanged.
  *
  * Note that this document is provided 'as is',
  * WITHOUT WARRANTY of any kind either expressed or implied.
  */

package ds.interfaces;

/** Simple interface for lists
 */

import java.util.Iterator;

import ds.util.Invariant;
import ds.util.E;

public interface List
    extends Iterable<E>, Invariant {

    boolean isEmpty();
    boolean member(E e);
    int     length();
    E       head();
    List    tail();
    E       last();
    List    init();
    E       at(int i);
    List    append(E e);
    List    cons(E e);
    List    concat(List l2);
    List    reverse();
    List    copy();

    // inherited

    // Iterator<E> iterator();
    // boolean inv();
}