[clean-list] State-transformer monad and uniqueness typing...

[Isabelle]

Martin Wierich wrote:

> Isabelle wrote:
> > I have defined as follows the state-transformer monad type :
> >
> > :: STM s x = { stm :: s -> ( s , x ) }
> ...
> > I do not send detailed sources here because I suspect there is a basic
> > flaw in the STM type definition, clashing with uniqueness typing, but I
> > can't see where...
>
> Try
>
>   :: STM *s x = { stm :: .(s -> ( s , x )) }
> ...

Thanks Martin, it works.

I discovered also that

:: STM .s x = { stm :: .( s -> .( s , x ) ) }

is correct.

Now it remains for me to understand exactly why :-)

Fabien Todescato