Suppose we have a Prolog source file
foreign(f1, p1(+integer,[-integer])). foreign(f2, p2(+integer,[-integer])). foreign_resource(ex, [f1,f2]). :- load_foreign_resource(ex).
and a C source file
ex.c with definitions of the functions
f2, both returning
SP_integer and having an
SP_integer as the only parameter. The conversion declarations in
ex.pl state that these functions form the foreign resource
ex. Normally, the C source file should contain the following
two line near the beginning (modulo the resource name):
#include <sicstus/sicstus.h> /* ex_glue.h is generated by splfr from the foreign/[2,3] facts. Always include the glue header in your foreign resource code. */ #include "ex_glue.h"
To create the linked foreign resource, simply type (to the Shell):
% splfr ex.pl ex.c
The linked foreign resource ex.so (file suffix .so
is system dependent) has been created. It will be dynamically linked by
:- load_foreign_resource(ex). when the file
ex.pl is loaded. For a full example, see Foreign Code Examples.
Dynamic linking of foreign resources can also be used by runtime systems.