[Haskell-cafe] Stupid question #374: why is MaybeT not in the standard library?

[Luke Palmer]

On Mon, Dec 22, 2008 at 6:52 PM, Antoine Latter <aslatter at gmail.com> wrote:

> 2008/12/22 Luke Palmer <lrpalmer at gmail.com>:
> > Yeah, it'd be useful.  Doesn't really matter, though, because it's on
> > Hackage (http://hackage.haskell.org), so it's just a cabal install
> > MaybeT away.
> > Now that cabal and cabal-install are reasonably mature, we really don't
> have
> > to worry about what's blessed as "standard" anymore.  :-)
>
> Although I still had to use my own because I wanted a MonadPlus
> instance.  I would offer a patch, but since there's more than one
> useful MonadPlus instance for MaybeT it probably still wouldn't be
> right for everyone.


There are?  The only two I can think of are the left-biased and its dual, in
which case the convention is to choose the left-biased one.  Is there
another?

Luke
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