Re: [Haskell-cafe] Problems with type family in a class

On Sun, 20 Jul 2014 00:33:00 -0400, Leza Morais Lutonda wrote:

Thanks for the explanation, Niklas, now I understand (I'm understanding) type families and I left with:

class (Signal s, ComplexSignal (ComplexSignalType s), RealSignalType (ComplexSignalType s) ~ s) ⇒ Complexable s where

type ComplexSignalType s

class (Complexable s) ⇒ FourierTransformable s where fft ⦂ ∀ csx. (csx ~ ComplexSignalType s, ComplexSignal csx) ⇒ csx → csx

Maybe more complex than normal?

Thanks again.

Hmm, to be honest I'm not sure if this is effectively any different from what you had in your original example. Does this work as expected w.r.t type inferencing and instance selection?