[slang-users] USIng the LIST inside of C ...

[Ben Duncan]

I would like to USE the LIST functions:
such as :

  list = { "hello", 7, 3.14, {&sin, &cos}}

   then

  list_insert (list, 0, "hi");
  list_append (list, 0, "there");
  list_insert (list, -1, "before");
  list_append (list, -1, "after");

inside of my C SLAG programs, then return the created LIST
back to the S-Lang program.

Any Pointers on how to go about doing this ?

Here is a snippet of code of my doing this with python :

static PyObject *apgn_extrall ( apgnobject * dp, PyObject * args )
{
   PyObject *list;
   PyObject *attr_string;
   char message[256];
   char *Buffer;
   char END_TEXT [] = { 0xff, '\0' } ;
   int Attribute = 0;
   int idx = 0;
   int status = 0;
   int MV_CNT = 0;
   int SubVal = 0;

   if ( !PyArg_ParseTuple ( args, "i:extrall", &Attribute ) )
     return NULL;
   check_apgnobject_open ( dp );

   if ( dp->rec_key == NULL )
     {
       sprintf ( message, "No Record has been read! " );
       PyErr_SetString ( ApgnError, message );
       return NULL;
     }

   if ( Attribute < 1 )
     {
       sprintf ( message, "Invalid Attribute Requested! " );
       PyErr_SetString ( ApgnError, message );
       return NULL;
     }

   /* Create and Allocate a Managed Python List */
   list = PyList_New ( 0 );
   if ( list == NULL )
     {
       Py_DECREF ( list );
       sprintf ( message, "CANNOT Allocate appgen LIST in extrall! " );
       PyErr_SetString ( ApgnError, message );
       return NULL;
     }

   /* Check OUR attribute status for number of Multi values */
   MV_CNT = db_stat( dp->di_apgn, Attribute, -1 ) ;
   if ( MV_CNT == -1 )
     {
      return list ;
     }

   if ( MV_CNT == 0 )
     {
      return list ;
     }

   /*
      Go thru Extracting EACH attribute from a  Multi value
      Append each of the STRINGS return to the end of the list
   */
   for (idx = 1 ; idx <= MV_CNT ; idx++ )
     {
        Buffer = str_extract ( dp->di_apgn, Attribute, idx );
        attr_string = PyString_FromString ( Buffer );
        free ( Buffer );

        status = PyList_Append ( list, attr_string );
        Py_DECREF ( attr_string );

        if ( status != 0 )
         {
           sprintf ( message, "Invalid MV BUFFER APPEND ! " );
           PyErr_SetString ( ApgnError, message );
           Py_DECREF ( list );
           return NULL;

         }
     }

   /* Return the list back to the Python program */
   return list;

}


.. As Always, Thanks ....


-- 
Ben Duncan  - Business Network Solutions, Inc. 336 Elton Road  Jackson MS, 39212 

"Never attribute to malice, that which can be adequately explained by stupidity"
        - Hanlon's Razor