QP_term_type()

Synopsis

     #include <quintus/quintus.h>
     
     int QP_term_type(term)
     QP_term_ref term;
     

Tests the type of Prolog terms in C.

Description

QP_term_type() returns the type of a Prolog term that is passed to it as argument. The returned value is one of the following constants defined in the file <quintus/quintus.h>: QP_VARIABLE, QP_INTEGER, QP_ATOM, QP_FLOAT or QP_COMPOUND.

Examples

print_type() is a C function that prints the type of the Prolog term passed to it.

                                     
foo.pl
     
     
     foreign(print_type, c, print_type(+term)).
     

                                      
foo.c
     
     
     #include <quintus/quintus.h>
     
     void print_type(term)
     QP_term_ref term;
     {
         switch (QP_term_type(term)) {
         case QP_VARIABLE:
             QP_printf("Term is a variable\n");
             break;
         case QP_INTEGER:
             QP_printf("Term is an integer\n");
             break;
         case QP_FLOAT:
             QP_printf("Term is a float\n");
             break;
         case QP_ATOM:
             QP_printf("Term is an atom\n");
             break;
         case QP_COMPOUND:
             if (QP_is_list(term)) {
                 QP_printf("Term is a list\n");
             } else {
                 QP_printf("Term is a compound term\n");
             }
             break;
         }
     }
     

See Also

QP_is_*(), QP_get_*(), QP_put_*(), QP_new_term_ref()