Hello Conal,I have a type
which is part of the grapefruit-data package. I introduced it because I wanted to make use of the fact that for every applicative functor a and every monoid m, a m is again a monoid.
defines an instance
(Applicative a, Monoid m) => Monoid (WrappedApplicative a m)
is just application of a
type to a
* -> *
type. So it seems much better to define a “composition” type which “composes” a unary type with a nullary type. Such a “composition” would be an instance of
if an applicative functor is composed with a monoid. Thereby I could get rid of
is also type application. Maybe the above ideas could also be used to remove
. Maybe this would lead us to libraries which don’t introduce all kinds of wrapper types.
What do you think?
-- Wolfgang Jeltsch 18:23, 4 December 2007 (UTC)