Proposal: Num instance for (a -> b)

Sun Nov 11 05:00:46 UTC 2018

On Sun, 11 Nov 2018, Henning Thielemann wrote:

> On Sat, 10 Nov 2018, Daniel Cartwright wrote:
>
>> relevant reddit comment 
>> thread:https://www.reddit.com/r/haskell/comments/9vtis5/the_universe_of_discourse_i_hate_the_environment/e9f1lea?utm_so
>> urce=reddit-android
>
> https://wiki.haskell.org/index.php?title=Num_instance_for_functions&oldid=36632
>
> In short: It would make 2(x+y) no longer a type error but equivalent to 2. We 
> would lose a lot of type safety for little syntactic gain.

Btw. before adding more Wat instances please implement the GHC warning 
about such instances:
    https://ghc.haskell.org/trac/ghc/ticket/11796