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Hello Conal,
I have a type
defined in
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)
.
Actually,
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
.
Interestingly,
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)
