/* File: stringitem.C

   string operations needed for ListNode and List Classes.
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "stringitem.h"

ListItem::ListItem() {		/* default constructor */

   item = NULL ;
}


ListItem::ListItem(data x) {	/* alternate constructor */

   if (x == NULL) return ;

   item = strdup(x) ; 
   if (item == NULL) {
      fprintf(stderr, "could not duplicate string\n") ;
      exit(1) ;
   }
}


ListItem::~ListItem() {		/* destructor */

/* Debugging:   

   printf("ListItem Destructor: (%p, %s)\n", item, item) ;
*/
   if (item != NULL) free(item) ;
}


data ListItem::copy() {		/* make a copy */
   char *str ;

   if (item == NULL) return NULL ;

   str = strdup(item) ;
   if (str == NULL) {
      fprintf(stderr, "could not duplicate string\n") ;
      exit(1) ;
   }
   return str ;
}


/* Compare data in host object with given data.
   <0 is smaller, =0 is equal, >0 is bigger 
*/
int ListItem::compare(data x) {      

  if (item == NULL && x == NULL) return 0 ;
  if (item == NULL) return -1 ;
  if (x == NULL) return 1 ;

   return strcmp(item, x) ;
}


void ListItem::print() {       /* print to stdout */
   if (item != NULL) {
/* Debugging:
      printf("(%p,%s)", item, item) ;
*/
      printf("%s", item) ;
   }
}