Re: [Haskell] Signature error because the order

Hi Luis, Luis Cabellos wrote:

But if I change the order of *Show* and *Num* in the signature of /prettyShow/ it works.

It's a GHC problem? it's normal than signature is order-dependent?

I think this is on purpose. The error specifically says that the contexts must be identical (rather than containing the same classes in arbitrary). I suspect this is how Haskell98 has specified it. If you enable the RelaxedPolyRec language extension, this restriction no longer applies and your code compiles fine. Hope this helps, Martijn.