Hi.
On 23 August 2013 13:29, Nicolas Trangez wrote:
> Did anyone ever consider using type-level literals (strings) to 'name'
> effects (or transformer layers when using monad stacks)?
>
Edwin Brady had this in his effects library in Idris.
http://www.idris-lang.org/documentation/effects/
Ozgur
On Fri, 2013-08-23 at 08:06 +, o...@okmij.org wrote:
> > It will
> > arbitrarily pick the first match in the former and fail to compile
> in
> > the latter case.
> Of course we can have duplicate layers. In that case, the dynamically
> closest
> handler wins -- which sounds about right (think o
I must stress that OpenUnion1.hs described (briefly) in the paper
is only one implementation of open unions, out of many possible.
For example, I have two more implementations. A year-old version of
the code implemented open unions *WITHOUT* overlapping instances or
Typeable.
http://okmij.
For the open union used in extensible effects, apart from using the
Typeable mechanism, is there a more protected way to implement
the open sum type?
I managed to modified the Member class given in the paper, but
ended up having to use the vague OverlappingInstance. That's not
quite what I hope. I
To be honest I'm not so sure about these "effects"... Simply the fact that
the Member class needs -XOverlappingInstances means that we cannot have
duplicate or polymorphic effects. It will arbitrarily pick the first match
in the former and fail to compile in the latter case.
Furthermore I don't re
The paper is very interesting:
http://www.cs.indiana.edu/~sabry/papers/exteff.pdf
It seems that the approach is mature enough and it is better in every way
than monad transformers, while at the same time the syntax may become
almost identical to MTL for many uses.
I only expect to see the librar
Perhaps effect libraries (there are several to choose from) could be a
better answer to Fork effects than monad transformers. One lesson from
the recent research in effects is that we should start thinking what
effect we want to achieve rather than which monad transformer to
use. Using ReaderT or
TLDR: New forkable monad/transformer suggestion
http://pastebin.com/QNUVL12v(hpaste is down)
Hi,
There are a dozen packages on hackage defining a class for monads that can
be forked, however none of these are modular enough to be useful in my
opinion.
In particular the following are not addresse
