Deriving Typeable instances

Simon Marlow simonmar at microsoft.com
Wed Aug 10 05:58:12 EDT 2005


On 09 August 2005 17:16, Simon Peyton-Jones wrote:

> I'm not against this, although you can work around the problem by
> adding a library that defines the missing type classes (Typeable8,
> Typeable9 etc), and making your compiler generate the instance
> itself.  There is nothing magic about 'deriving'; it's just
> convenient. 

If the arity is >7, couldn't we just generate a Typeable instance,
rather than the TypeableN instance?  It would mean you wouldn't get the
benefits of TypeableN, but at least you'd have Typeable.

Cheers,
	Simon



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