Am Samstag, 12. Februar 2005 01:42 schrieb [EMAIL PROTECTED]: > Iavor Diatchki writes in response to Thomas JÃger > > > Literal patterns need equality: > > f 2 = e > > is like: > > f x | x == 2 = e > > > > These do not force the 'Num' class to be a superclass of 'Ord' or > > 'Eq'. If 'Num' was not a superclass of 'Eq', whenver you used a > > literal pattern there would be an extra constraint that there should > > be equality on the corresponding type. > > You mean of course that Eq is a superclass of Num, not the reverse. > > Anyway, I always hated this, especially working with functional objects > for which I had some arithmetic defined... > > > Jerzy Karczmarczuk >
I feel somewhat similarly. I think it would be nice to have numerical classes where the arithmetic operations are provided, so you can naturally add functions &c, and then have Num a subclass where fromInteger and instances of Eq and Show are added. Daniel _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
