wangmeng at comp.nus.edu.sg
Wed Jan 14 18:20:02 EST 2004
Anybody knows why the following code does not work?
> class Foo n
> data Erk n = Foo n => Erk
All of the type variables in the constraint `Foo n' are already in
(at least one must be universally quantified here)
When checking the existential context of constructor `Erk'
In the data type declaration for `Erk'
Failed, modules loaded: none.
Is there any reason for this error?
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