Original-Via: uk.ac.nsf; Sat, 9 Nov 91 15:09:09 GMT
| Date: Fri, 8 Nov 1991 18:20:38 EST
| From: john peterson <[EMAIL PROTECTED]>
| Subject: Superclass instances (Oops)
|
| I'll still stick with my opinion on this one, though. Here's more
| reasons:
|
| a) This represents a potentially large number of new instances which
| may be implicitly inserted into the program.
| b) I feel it's more likely that a missing superclass would be the
| result of a programmer error than an intent to omit the superclass.
| c) We have made a stylistic commitment to explicitly listing the
| classes generated by a `deriving' clause; why should this
| situation be different?
I think reason (c) is the best one. I might not agree with necessity
to list all derived instances in a @deriving@ clause, but since we
have made that decision, we should be consistent here.
--Joe
