]> Hi all. I'm trying to learn how to programm lazily, but I'm kinda stuck. I've a list, say let l = [[1;2;3];[4;5];[6;7;8]] and I want to produce all possibile permutations (1,4,6) (1,4,7) (1,4,8) (1,5,6) (1,5,7) ... it can easily be done with List.iter and a couple of recoursive steps, but I'm trying to code it in a tail-recoursive style and using lazy evaluation. Hence my problem is to write a function that gets the list and gives me back one result (1,4,6) and a lazy structure that encode the rest of the computation... I looked at lazy streams or lazy lists to solve this problem, but I was unable to come up with any nice solution... does anybody have any hints ? p ps: this problem is a stripped down version of a more complicated one that involves big data structures, that's why I'm trying to come up with an optimized solution. -- ++ As I grow older, I pay less attention to what men say. I just watch what they do. Andrew Carnegie (1835-1919). ++ Please avoid sending me Word or PowerPoint attachments. See http://www.fsf.org/philosophy/no-word-attachments.html ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners