/*
 * Project : Embedding SWI-Prolog in a C program.
 *
 * Author : Lens Stephane Ulg
 * Date   : 10/2009
 *
 * Check if an integer is prime.
 *
 */

#include <stdio.h>
#include <pl/SWI-Prolog.h>



int main(int argc, char *argv[])
 {
  int res, nb = 0;

  /* Initialise Prolog */
  if ( !PL_initialise(argc, argv) )
    PL_halt(1);

  /* Get the integer to test */
  printf("Number to test (-1 to quit) ? : ");
  res = scanf("%i", &nb);

  while (res == 1 && nb > -1)
    {
      /* Transform the integer to Prolog term */
      term_t h0 = PL_new_term_refs(1);
      PL_unify_integer(h0, nb);

      /* Call the predicate */
      res = PL_call_predicate(NULL, PL_Q_NORMAL,
                              PL_predicate("prime", 1, "user"), h0);

      if (res)
    	  printf("%i is prime.\n", nb);
      else	
    	  printf("%i is not prime.\n", nb);

      printf("\nNumber to test (-1 to quit) ? : ");
      res = scanf("%i", &nb);
    }

  printf("\n> Exit\n");
  
  /* Stop Prolog */
  PL_halt(0);
  return 0;
}