[Template-haskell] Problem with TH

[Ian Lynagh]

On Wed, Nov 17, 2004 at 05:12:38PM +0000, Keean Schupke wrote:
> I am using the new existential datatype support (great!) -  but now when 
> I patch in fundep support
> (more or less as I posted before) adding an extra field to ClassD, I 

I've just committed support for this - sorry for the delay.

> Now when I include a definition:
> 
>    [d| class Test x |]
> 
> I get the error:
> 
> ghc-6.3: panic! (the `impossible' happened, GHC version 6.3):
>        deSugar/DsMeta.hs:925:4-41: Irrefutable pattern failed for 
> pattern [elt_ty]
> 
> Any idea why this might be happening (why is the error in DsMeta, when 
> the TH
> stuff is in hsSyn/Convert.lhs and typecheck/TcSplice.lhs?

The bit in TcSplice is for the reify keyword. DsMeta handles
the conversion from GHC's internal representation to the TH
representation.


Thanks
Ian