The use case I'm interested in is for exploratory programming, I define a
type-driven compositional data-flow, and use void types until I'm ready to
start filling in the gaps. Some data-dependencies may require class
instances, and for this I currently use a stand-alone instance with
undefined definitions.
Maybe there's a better way to go about this though?
On Tue, Oct 29, 2013 at 3:31 PM, AntC
Lyndon Maydwell
writes: I was wondering if it's possible to have automatic deriving for some classes for the Void type. ...
Hi Lyndon, I'm struggling to see any use case for that.
You'd 'achieve' `show (undefined :: Nada)` crashing your program at run- time; rather than failing to compile (if you didn't have the instance).
Just bite the bullet and give your Void type a constructor.
AntC
I guess the obvious one would be Show.
data Nada deriving Show
{* instance Show Nada where show _ = undefined *}
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