[rmonad] RMonadFix

Peter Gavin pgavin at gmail.com
Sat Mar 21 23:44:47 EDT 2009

On 3/19/09 6:01 PM, Ganesh Sittampalam wrote:
> Hi,
>>> On Fri, 7 Nov 2008, Peter Gavin wrote:
>>>> I've needed to add support for MonadFix to rmonad. I've attached a
>>>> patch with my code.
> I've just realised that this leaves out a case for unEmbed (Bind (MFix
> m) f). In addition, I can't actually figure out how to write such a case
> and I am beginning to suspect it's not possible.
> Any thoughts? I've been through the mfix laws in the source of
> Control.Monad.Fix, and also checked Erkok and Launchbury's mfix paper,
> and I can't see anything that can be sensibly used here. Hopefully I'm
> missing something, though.

Hi Ganesh,

I guess this didn't come up before because I didn't need the embedding feature. 
  I've played with it a bit, but your right, if it's even possible, it'll be 
tricky to do.

I'll keep investigating, and if I come up with anything, I'll let you know.


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