#include "structures.h"
/*
============================================================
|                          plus()                          |
|----------------------------------------------------------|
| Params : 1)an integer representing the number of arguments
|          2)an array of terms                             |
| Desc   : adds the numbers                                |
|                                                          |
| Returns: a term representing the sum of the  numbers     |
|==========================================================|
*/
struct term *plus(int arity, struct term **args)
{
   int i;
   int sum=0;
   for (i=0;i<arity;i++)
   {
      if (args[i]->term_type!=INTEGER)
         return NULL;
      else
         sum=sum+args[i]->functor;
   }
   return maketerm(INTEGER, sum,0,NULL,NULL);
}


/*
============================================================
|                           now()                          |
|----------------------------------------------------------|
| Params : 1)                                              |
|                                                          |
| Returns:a term representing the current time             |
|==========================================================|
*/
struct term *now(int arity, struct term **args)
{
   if (arity!=0) return NULL;
   else return maketerm(INTEGER,time(NULL),0,NULL,NULL);
}






/***********************************************************************/

/* read_in the automatically generated evaluable_functions.aux file */
#include "evaluable_functions.aux"
int evaluable_functions_count=
   sizeof(eval_functions)/sizeof(EvalFunctionDescriptor);


/*
============================================================
|                    get_eval_function()                   |
|----------------------------------------------------------|
| Params : 1)an Integer                                    |

| Desc   :                                                 |
|                                                          |
| Returns: a pointer to the function descriptor for that
           functor, if one exists. Null otherwise          |
|==========================================================|
*/
EvalFunctionDescriptor *get_eval_function(int functor)
{
   int i;
   for(i=0;i<evaluable_functions_count;i++)
      if(eval_functions[i].functor==functor) return &eval_functions[i];
   return NULL;
}