20 Feb
2008
20 Feb
'08
11:31 a.m.
Hi
full -> Maybe (item, full)
Hrm, what exactly is the return data here? Is is the head and the tail if the list has >= 1 item, or Nothing otherwise? Or...?
Yes, its the projection onto another type: [] = Nothing (x:xs) = Just (x, xs)
What is the problem with MPTC in base?
MPTC is not a part of any Haskell standard. The rules surrounding MPTC are not clear. People want to remove MPTC's/functional dependencies, or modify them with associated types. Compilers such as nhc and yhc can't implement them. Once they are in Haskell', with an associated set of restrictions/overlap rules etc, then they can be freely used with the base library. Thanks Neil