In article <200307121058.21556.alastair@reid-hoffmann.net>,
Alastair Reid
One way to overcome part of this problem would be to generalize the idea of 'type synonyms' to allow 'context synonyms'. For example, we have type synonyms like:
type Point = (Int,Int)
we could have 'context synonyms' like:
class Num a => (Add a, Subtract a, FromInteger a, Eq a, Multiply a, ...)
That would be quite unnecessary. Simply write this: class (Add a, Subtract a, FromInteger a, Eq a, Multiply a, ...) => Num a; instance (Add a, Subtract a, FromInteger a, Eq a, Multiply a, ...) => Num a; And now you can write this: invert :: Num a => Matrix a -> Matrix a I use this idiom quite frequently for "joining" classes together. -- Ashley Yakeley, Seattle WA