Subversion Repositories programming

public interface Map {

  public Object get(Object key);

  // RETURN: value;

  // POST: if value!=null, then (key,value) is in this map;

  //       if value==null, then no record in this map has the given key;

  public Object put(Object key, Object value);

  // RETURN: oldValue;

  // POST: if oldValue==null, then (key,value) is in this map;

  //       if oldValue!=null, then (key,oldValue) was in this map;

  public Object remove(Object key);

  // RETURN: oldValue;

  // POST: if oldValue==null, no record in this map has the given key;

  //       if oldValue!=null, then (key,oldValue) was in this map;

  public int size();

  // RETURN: n;

  // POST: this map contains n records;

}