[Haskell-cafe] Is there a way to make this code compose generic ?

[PICCA Frederic-Emmanuel]

----- Le 24 Avr 25, à 22:41, Li-yao Xia lysxia at gmail.com a écrit :

> You can delegate to another class that has a default implementation
> 
> instance GDSAK1 a => GDataSourceAcq (K1 i a) where
>   g'ds'Shape (K1 a) = g'ds'Shape'K1 a
> 
> class GDSAK1 a where
>   g'ds'Shape'K1 :: ...
>   g'ds'Shape'K1 _ = pure shape1
> 
> instance GDSAK1 (a DSAcq) where
>   g'ds'Shape'K1 = ...
> 
> instance GDSAK1 Degree
> instance GDSAK1 Double
> ...
> 
> You can also use an overlappable instance to not list all the instances,
> but the downside is you don't get an error if you forget to override it.

I prefer the first solution. I use haskell for the compiler errors :)

Do you know if there is some performance issue to use a new class for this ?

How can I be sure that all the method are statically resolve at the compile time ?

I do not know If I am clear.

thanks

Fred