int main()
{
put_structure("h", 2, 3); /* ?- X3 = h */
set_variable(2); /* (Z, */
set_variable(5); /* W), */
put_structure("f", 1, 4); /* X4 = f */
set_value(5); /* (W), */
put_structure("p", 3, 1); /* X1 = p */
set_value(2); /* (Z, */
set_value(3); /* X3, */
set_value(4); /* X4). */
print_register(1); /* drukowanie X1 */
dump_heap();
fail = false;
get_structure("p", 3, 1); /* X1 = p */
unify_variable(2); /* (X2, */
unify_variable(3); /* X3, */
unify_variable(4); /* Y), */
get_structure("f", 1, 2); /* X2 = f */
unify_variable(5); /* (X), */
get_structure("h", 2, 3); /* X3 = h */
unify_value(4); /* (Y, */
unify_variable(6); /* X6), */
get_structure("f", 1, 6); /* X6 = f */
unify_variable(7); /* (X7), */
get_structure("a", 0, 7); /* X7 = a */
printf("fail = %d\n", (int)fail);
print_register(1); /* drukowanie X1 */
dump_heap();
return 0;
}
static int unify_list_from_span(term_t list, clingo_symbol_t const *syms,
size_t slen) {
int rc;
term_t tail = PL_copy_term_ref(list);
term_t head = PL_new_term_ref();
term_t tmp = PL_new_term_ref();
clingo_symbol_t const *it, *ie;
for (it = syms, ie = it + slen; it != ie; ++it) {
PL_put_variable(tmp);
if (!(rc = (unify_value(tmp, *it) && PL_unify_list(tail, head, tail) &&
PL_unify(head, tmp)))) {
goto out;
}
}
if (!(rc = PL_unify_nil(tail))) {
goto out;
}
out:
return rc;
}
static int unify_value(term_t t, clingo_symbol_t v) {
// NOTE: the clingo_symbol_* functions below only fail
// if applied to the wrong type
// they do not allocate
switch (clingo_symbol_type(v)) {
case clingo_symbol_type_number: {
int number;
clingo_symbol_number(v, &number);
return PL_unify_integer(t, number);
}
case clingo_symbol_type_string: {
char const *str;
clingo_symbol_string(v, &str);
return PL_unify_chars(t, PL_STRING | REP_UTF8, (size_t)-1, str);
}
case clingo_symbol_type_infimum: {
return PL_unify_term(t, PL_FUNCTOR, FUNCTOR_hash1, PL_ATOM, ATOM_inf);
}
case clingo_symbol_type_supremum: {
return PL_unify_term(t, PL_FUNCTOR, FUNCTOR_hash1, PL_ATOM, ATOM_sup);
}
case clingo_symbol_type_function: {
// FIXME: functions can have signs represented as -f(x) in gringo
char const *str;
clingo_symbol_t const *args;
size_t size;
int rc;
clingo_symbol_name(v, &str);
clingo_symbol_arguments(v, &args, &size);
if (size == 0) {
if (!(rc =
PL_unify_chars(t, PL_ATOM | REP_UTF8, (size_t)-1, str))) {
goto out_function;
}
} else {
clingo_symbol_t const *it, *ie;
atom_t name;
term_t arg;
int i;
name = PL_new_atom(str);
if (!(rc = PL_unify_functor(t, PL_new_functor(name, size)))) {
goto out_function;
}
PL_unregister_atom(name);
arg = PL_new_term_ref();
for (i = 1, it = args, ie = it + size; it != ie; ++it, i++) {
_PL_get_arg(i, t, arg);
if (!unify_value(arg, *it)) {
goto out_function;
}
}
}
out_function:
return rc;
}
default:
assert(FALSE);
return FALSE;
}
}
