MR K P SCHUPKE
k.schupke at imperial.ac.uk
Wed Oct 13 10:02:30 EDT 2004
>look at the user manual.
Okay, I see the Generic type class stuff does not support multi
parameter type classes. I guess I am stuck - any suggestions as to
how best do this?
I wish to be able to derive type level labels for datatypes, like
data Fred a = Fred a deriving TTypeable
generates the instance:
instance TTypeable a al => TTypeable (Fred a) (NCons (N3 (N4 (N5 Nil))) (TCons al Nil))
where (N3 (N4 (N5 Nil))) is the result of a hash function on the name "Fred".
I have looked at TcDeriv but I don't know enough of the compiler internals to see
how this would be added to the current implementation... Can you give me some pointers
on how to do this?
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