Add Applicative instance for STM

[Roel van Dijk]

On Mon, May 17, 2010 at 10:27 AM, Jesper Louis Andersen
<jesper.louis.andersen at gmail.com> wrote:
> On Sun, May 16, 2010 at 7:24 PM, Bas van Dijk <v.dijk.bas at gmail.com> wrote:
>>
>> I just created a new patch that adds the Applicative and Alternative
>> instances for GHC.Conc.STM to Control.Applicative (guarded in a #ifdef
>> __GLASGOW_HASKELL__ block).
>
> +1 from me here. I have a few uses for an applicative and alternative
> instance of STM.

Also +1 from me. I needed to work around STM not having an Applicative
instance in an as of yet unreleased package.