[Haskell-cafe] primitive operations in StateT

[Clark Gaebel]

The monad my code is currently written in is:

type MC = MCT Identity -- where MCT is the monad transformer version of it.

I have two options for threading state through this:

    MCT (ST s) a
    StateT s MC a

The first option would work if I had some function with the signature

MCT Identity a -> MCT (ST s) a

but I know of no such function, and the second one would work if I had some
way of making StateT a member of PrimMonad.

Can I see an example with 'lift'?

  - Clark

On Tuesday, April 16, 2013, Ivan Lazar Miljenovic wrote:

> On 16 April 2013 15:04, Clark Gaebel <cgaebel at uwaterloo.ca <javascript:;>>
> wrote:
> > Hi list!
> >
> > I want to use MVectors in a StateT monad transformer.
> >
> > How do I do that? StateT isn't a member of 'PrimMonad', and I have no
> idea
> > how to make it one.
>
> You can use Control.Monad.Trans.lift to lift the PrimMonad operations
> to PrimMonad m => StateT s m
>
> >
> > Regards,
> >   - Clark
> >
> > _______________________________________________
> > Haskell-Cafe mailing list
> > Haskell-Cafe at haskell.org <javascript:;>
> > http://www.haskell.org/mailman/listinfo/haskell-cafe
> >
>
>
>
> --
> Ivan Lazar Miljenovic
> Ivan.Miljenovic at gmail.com <javascript:;>
> http://IvanMiljenovic.wordpress.com
>
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