constant space `minimum'

Simon Marlow responds on the subject of constant space `minimum':

In 6.4, minimum & maximum will have specialised versions for Int & Integer, which will run in constant stack space. We can't do this in general, because minimum/maximum have the type

(Ord a) =3D> [a] -> a

and we can't assume that the comparison operations for any given type are always strict.

I meant that the implementation like minimum [x] = x minimum (x:y:xs) = if x > y then minimum (y:xs) else minimum (x:xs) is correct, and on the other hand, GHC compiles it more readily into an efficient code than the version done via foldl or such. ----------------- Serge Mechveliani mechel@botik.ru