On 2006-03-20, Wolfgang Jeltsch
Am Freitag, 17. März 2006 18:49 schrieb Ross Paterson:
[...]
Also, toEnum and fromEnum would make more sense mapping from and to Integer.
Why do we need toEnum and fromEnum at all? As far as I know, they are merely there to help people implement things like enumFrom.
Which could still be useful.
It's often not clear how toEnum and fromEnum should look like. How should they be implemented for Time.Day, for example? Should the days corresponds to the integers 0 to 6 or 1 to 7?
I believe that 0 to n-1 is the standard representation that deriving Enum currently uses.
It seems that succ and pred are unused.
No, I use them. In my opinion, it makes much more sense to write succ n than n + 1.
Agreed, for non-arithmetical types. -- Aaron Denney -><-