Postfix type operator support
Motivation
Just as there's support for postfix operators on the value level, it would be nice to have postfix operators on the type level:
data Some f where
Some :: f a -> Some f
type (?) = Some
thing :: f ? -> f ?
thing (Some f) = Some f
Currently, GHC says "Operator applied to too few arguments: ?
".
Proposal
Instead, support postfix operators on the type level, by parsing f ?
as (?) f
.