On Thu, Jul 21, 2011 at 10:27 AM, Meikel Brandmeyer <m...@kotka.de> wrote:
> Hi, > > Am Donnerstag, 21. Juli 2011 16:06:23 UTC+2 schrieb Ambrose > Bonnaire-Sergeant: > > >> You do not need to look at the surrounding code to know what (geto x y > z) does. > >> It establishes the geto relation between x y z. x must be some key in, y > must be a > >> vector of key-value pairs and z must be a value in y. The relation > guarantees this. > > > > I think I understand where Meikel is coming from. > > > > The function can be used in radically different ways, depending on the > values of the arguments, > > which is somewhat unnerving. (I sympathize) > > Thanks for explaining my point than I did. Here some examples: > > logic-introduction.core=> (run* [q] (geto 'f [['f :- Integer] ['g :- > Integer]] Integer) (== q true)) > (true) > logic-introduction.core=> (run* [q] (exist [a] (geto 'f [['f :- Integer] > ['g :- Integer]] a) (== q a))) > (java.lang.Integer) > logic-introduction.core=> (run* [q] (exist [a] (geto a [['f :- Integer] ['g > :- Integer]] Integer) (== q a))) > (f g) > > Basically the purpose *why* I call geto are always different (Maybe "call" > is already wrong?). With (get x y z) in pure Clojure that's not the case. > Free (fresh?) variables kind of feel like side-effects for my eyes. But > again: I have no clue whatsoever about logic programming. Maybe I just have > to train to look with the right glasses at the code. > > Meikel > geto establishes a relation and you can find out which values satisfy that relation. Functional programming thinking won't help much here - consider that in pure logic programs order doesn't even matter most of the time - because you are establishing *relations* between values. I don't see the correlation to side-effects here at all since order does not determine the outcome of the program. David -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
