Re: [Caml-list] Monad Library?

[Malcolm Matalka <mmatalka@gmail.com>]

I haven't experienced a strong need for a state monad in Ocaml.  I do
tend to use Core's Option and Return (>>=) functions for sequencing code
though.

/M

P.S. In general Ocamler's seem to prefer to write 'Store x' rather than
'Store(x)'


Chris Yocum <cyocum@gmail.com> writes:

> Thanks everyone,
>
> So basically from what I understand this is kind of like a StateMonad.
> It seems to me that the state monad (hiding state in the type system)
> would be a large boon.
>
> So, for instance,
>
> module type MONAD =
> sig
>   type 'a t
>   val return : 'a -> 'a t
>   val bind : 'a t -> ('a -> 'b t) -> 'b t
> end
>
> module StateMonad : MONAD =
> struct
>   type 'a t = Store of 'a
>   let return x = Store(x)
>   let bind s f =
>     match s with
>       | Store(x) -> f x
>   let access = function Store(x) -> x
> end
>
> This is a very, very basic implementation of a state monad?
>
> Thanks again.
>
> Chris
>
> On Fri, Nov 23, 2012 at 09:59:30PM +0100, Michał Kurcewicz wrote:
>> If Core is too complex for you then you may take a look at spotlib - a
>> small and elegant library written by Jun Furuse:
>> 
>> https://bitbucket.org/camlspotter/spotlib
>> 
>> I use it together with pa_monad_custom for all my monad needs.
>> 
>> Best,
>> 
>> --mk
>> 
>> On Fri, Nov 23, 2012 at 12:43 PM, Chris Yocum <cyocum@gmail.com> wrote:
>> > Hi,
>> >
>> > I was looking into using Monads in my programs but I am slightly at a
>> > loss as to what library is in general use.  There is pa_monad but that
>> > seems to be a ocamlp4 exention and not a library.  There is
>> > http://lambda.jimpryor.net/monad_library/ but that doesn't seem to be
>> > in opam or in godi so I am unsure as to its status.
>> >
>> > Does anyone have any suggestion for a well supported monad library for
>> > Ocaml?
>> >
>> > All the best,
>> > Chris