[Haskell-cafe] Default definitions for associated type synonyms

Isaac Dupree isaacdupree at charter.net
Mon Jun 2 10:45:31 EDT 2008


Dreixel wrote:
> Hello,
> 
> Does anyone know if it is possible to specify a default definition for an
> associated type synonym? When I tried:
> 
> class A a where
>>   type B a = a
>>
> 
> GHC (version 6.9.20080309) told me: "Type declaration in a class must be a
> kind signature or synonym default". However, when I look at the parser I see
> no way to specify such synonym default. Is this possible?

I'm curious... so, cc'ing glasgow-haskell-users mailinglist because the 
question is more likely to be noticed by relevant people there.

> Thanks,
> Zé Pedro


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