[Haskell] ANNOUNCE: reference 0.1

[Bas van Dijk]

On Mon, Sep 6, 2010 at 11:55 PM, Maciej Piechotka <uzytkownik2 at gmail.com> wrote:
> Reference is class which generalizes references and monads they exists
> in. It means that IORef, STRef and others can be accessed by common
> interface.
>
> Currently it is of form:
>
> class Reference r m where
>
> 1. There was a proposal to rename the class to MonadRef or
> MonadReference. IMHO it would imply m -> r functional dependency and
> therefore disallow the instances for both MVar IO and IORef IO
>
> 2. Should the functional dependencies or type famillies be introduced?
> Personally I don't think so as I would like to allow all of the
> following:
>
>  - IORef IO
>  - MVar IO
>  - IORef (ContT IO)
>  - MVar (ContT IO)
>
> Any feedback mostly welcome.
>
> Regards
> PS. Darcs repository will be available soon
>
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>

I've played with a somewhat similar idea:

darcs get http://code.haskell.org/~basvandijk/code/only-read-or-write-vars

API Docs + Hyperlinked source:
http://code.haskell.org/~basvandijk/code/only-read-or-write-vars/doc/html/only-read-or-write-vars/

This is not released (yet) because I'm unsure about the design.

Especially, I'm unsure whether parameterizing Readable with α is a good idea:

class Readable v m α | v → m where read ∷ v → m α

and whether parameterizing Writable with α and β is a good idea:

class Writable v α m β | v → m where write ∷ v → α → m β

They do allow some

Regards,

Bas