#include <sicstus/sicstus.h> int SP_get_functor(SP_term_ref term, SP_atom *name, int *arity);
*arity the canonical representation
and arity of the principal functor of a Prolog compound
term. If the value of
term is an atom, then that atom
is assigned to
*name and 0 is assigned to
*arity. This is
similar to calling
functor/3 with the first argument
bound to a compound term or an atom and the second and
third arguments unbound.
Zero if the conversion fails (as far as failure can be detected), and a nonzero value otherwise.
Accessing Prolog Terms.