How about a recursive function like this:
alln 1 ls = map (:[]) ls alln n ls = do a <- ls as <- alln (n-1) ls return (a:as)
Note that `ls :: [t]` and `all (n-1) ls :: [[t]]` has different types but it's okay because both are in the list monad.
Also, it can be done with list comprehensions:
alln' 1 ls = [[a] | a<-ls] alln' n ls = [a:as | a<-ls, as<-alln' (n-1) ls]
Works great, thanks a lot Matthias -- __________________________________________________________ ___ __ __ Dipl. Inf. Matthias Guedemann / __\/ _\ /__\ Computer Systems in Engineering / / \ \ /_\ Otto-von-Guericke Universitaet Magdeburg / /___ _\ \//__ Tel.: 0391 / 67-19359 \____/ \__/\__/ __________________________________________________________