[Haskell] A puzzle and an annoying feature

Lennart Augustsson lennart at augustsson.net
Thu Nov 25 15:30:45 EST 2004

Keean Schupke wrote:
> Daan Leijen wrote:
>> You are right, I feel like that too: one should expect that the type
>> checker can figure this out, and perhaps it is even really useful.
>> On the other hand, suppose you decide later to export the
>> class, and suddenly your code would no longer type check.
> I must have missed a mail... how could adding an export change the
> code?

If you export the class you can add another instance to it.  And now
my type variable would really be ambiguous.

	-- Lennart

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