constant space `minimum'

[Simon Peyton-Jones]

| I meant that the implementation like
| 
|              minimum [x]      = x
|              minimum (x:y:xs) = if x > y then minimum (y:xs)
|                                 else          minimum (x:xs)

It would be great if this was the defn of minimum in the Report. But it
isn't.

Consider 
 
data T = T1 | T2
instance Ord T where
   min x T2 = T2
   min x y   = error "urk"

Now try
	minimum [T1,T2,T2]
your defn gives "urk", but the Report gives T2.

Stupid, I know, but that's what it says.


So the best thing seems to be to give monomorphic instances of minimum
for types where we know the instances!

Simon