/* This program uses code from "Algorithms in C, Third Edition,"
 *               by Robert Sedgewick, Addison-Wesley, 1998.
 */


#ifndef LIST_INTERFACE_H
#define	LIST_INTERFACE_H

#include <stdio.h>

typedef struct node * link;
typedef struct struct_list * list;

link listFirst(list the_list);

link linkNext(link the_link);

int linkItem(link the_link);

// Creates and returns an empty list.
list newList();

// Deallocates memory for all nodes in the list.
void destroyList(list the_list);

// Creates a new link, that contains the value specified in the argument, 
// and that points to NULL. */
link newLink(int value);

// Inserts new_link to the specified list, at the position right after
// the link called "previous".
void insertLink(list my_list, link previous, link new_link);

/* Inserts new_link to the beginning of the list. */
void insertAtBeginning(list my_list, link new_link);

// Deletes the link coming AFTER link x. This function DOES NOT  DELETE
// link x itself. 
link deleteNext(list my_list, link x);

// Deletes the link at the beginning of the list.
link deleteFirst(list my_list);

void reverse(list the_list);

void printList(list my_list);

int listLength(list my_list);

void setFirst(list the_list, link first);

void setNext(link the_link, link next);

list listDeepCopy(list input);

// returns a new list that contains all values of input1 and all values 
// of input2
list mergeLists(list input1, list input2);

// modifies target, by inserting to it all links from source.
void mergeListsDestructive(list target, list source);

#endif	/* LIST_INTERFACE_H */