//  File: stringitem.C
//
//  string operations needed for ListNode and List Classes.

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


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

   str = NULL ;
}


// alternate constructor
//
ListItem::ListItem(const ListItem &x) {

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


// type converter
//
ListItem::ListItem(const char *s) {    
   if (s == NULL) {
      str = NULL ;
      return ;
   }
   str = strdup(s) ;
   if (str == NULL) {
      fprintf(stderr, "could not duplicate string\n") ;
      exit(1) ;
   }
}


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

/* Debugging:

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


// make a copy
//
ListItem *ListItem::copy() const {
   ListItem *newp ;

   newp = new ListItem ;
   if (str == NULL) return newp ;

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


// Copy contents of host object to x
//
void ListItem::copyto(ListItem &x) const {

   if (x.str != NULL) {
      free(x.str) ;
      x.str = NULL ;
   }
   if (str == NULL) return ;

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


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

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

   return strcmp(str, x.str) ;
}


// print to stdout
//
void ListItem::print() const {
   if (str != NULL) {
      printf("%s", str) ;
   }
}