/**
  * 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.
  */

#ifndef LIST_H__
#define LIST_H__ 1

/*--------------------*/

#define eqElement(x,y) (compare((x),(y)) == 0)
#define geElement(x,y) (compare((x),(y)) >= 0)

/*--------------------*/

typedef struct Node *List;

struct Node
{
  Element info;
  List next;
};


/*--------------------*/

extern List mkEmptyList(void);
extern int isEmptyList(List l);
extern Element head(List l);
extern List tail(List l);

/*--------------------*/

extern List removeHead(List l);

extern List cons(Element e, List l);

extern List addElem(Element e, List l);

/*--------------------*/

/* consistency check for sorted lists */

extern int invList(List l);

/*--------------------*/


#endif