Random items in Prolog

Question

I know I can do X is random(10). to get a random number from 0 to 10, but is there a similar command to get a random matching item?

Answer 1

You can implement it. Here is a version:

%% choose(List, Elt) - chooses a random element
%% in List and unifies it with Elt.
choose([], []).
choose(List, Elt) :-
        length(List, Length),
        random(0, Length, Index),
        nth0(Index, List, Elt).

From http://ozone.wordpress.com/2006/02/22/little-prolog-challenge/