Is There a Way to Consolidate Facts?

Question

Is there a way to turn this:

genre(blues).
gere(hiphop).
genre(rock).

Into something like this:

genre(blues;hiphop;rock).

*I know this does not work, but does something similar to this exist.

What is your reason for doing this? Are you trying to save time on typing? If so you can type like genre(rock). the ":- true." can be skipped in some compilers. — Farzad Khalafi, Oct 24 '12 at 00:21
I'd just like to point out Answer Set Programming systems supports exactly that syntax. — NotAUser, Oct 24 '12 at 08:57

score 2 · Accepted Answer · answered Oct 24 '12 at 00:37

2

You cannot consolidate facts, but you can turn them into a simple rule, like this:

genre(X) :- member(X, [blues, hiphop, rock]).

member/2 is a built-in list predicate in SWI to test list membership.

answered Oct 24 '12 at 00:37

score 1 · Answer 2 · answered Oct 24 '12 at 00:30

1

This lets you apply a predicate across all of the elements of a list, and will succeed only if all applications succeed.

test_list( _, [] ).
test_list( F, [H|T] ) :- P =.. [F,H], P, test_list( F, T ).

answered Oct 24 '12 at 00:30

Scott Hunter

By replacing `P =.. [F,H], P` by `call(F,H)` you have a more general version. This is usually called maplist: `maplist(F, L)` defined the same. – false Oct 24 '12 at 00:46
Thanks this is great, I appreciate your response. – Mr. Polywhirl Oct 24 '12 at 01:16

score 0 · Answer 3 · answered Oct 24 '12 at 13:46

0

You could use this syntax

genre(X) :- X=blues ; X=hiphop ; X=rock.

but personally I advice the member/2 way...

answered Oct 24 '12 at 13:46

CapelliC

3 Answers3