[Haskell-cafe] Alternative versus Monoid

[Bas van Dijk]

On 16 December 2011 05:26, Brent Yorgey <byorgey at seas.upenn.edu> wrote:
> I, for one, would be
> quite in favor of changing the current Monoid (Maybe a) instance to
> correspond to the failure-and-prioritized-choice semantics

So lets do this. Some questions:

1) What about the First type? Do we {-# DEPRECATE #-} it?

2) What about the Last type? It could be deprecated in favor of Dual.

3) Do we need a new type (like the current Maybe) for lifting
semigroups into a Monoid? IMHO we don't since the semigroup package
does a better job with the Option type (like Brent mentioned).

4) How much code will break from this change?

5) Anyone up for proposing this to libraries at haskell.org?

Regards,

Bas