If you want to parametrize over arbitrary monads, the modularized
appraoch (using functors or first-class modules) is adapted. But note
that for more specialized needs different interfaces are possible. For
example, Daniel Bünzli experimented with explicit inversion of control
instead of parametrization by monadic library, to solve the problem of
being Lwt/Async/"event loop" agnostic:
[Caml-list] Non-blocking IO interface design
https://sympa.inria.fr/sympa/arc/caml-list/2012-04/msg00055.html
I'm not sure how this worked out in the end, but this may be worth
looking at if you're still at the general design step.
> --
On Tue, Oct 23, 2012 at 1:52 AM, Jeremy Yallop <yallop@gmail.com> wrote:
> On 22 October 2012 23:09, Philippe Veber <philippe.veber@gmail.com> wrote:
>> A couple of libraries, like pgocaml for instance, define a functor over a
>> (monadic) thread implementation, like in the following:
>>
>> module type Thread = sig
>> type 'a t
>> val return : 'a -> 'a t
>> val bind : 'a t -> ('a -> 'b t) -> 'b t
>> end
>>
>> module F(T : Thread) : sig
>> val v : string -> string T.t
>> end
>>
>> Is it possible to define F as a function (ie at the value level)?
>
> Yes! Matías Giovannini has a blog post showing how to do just that:
>
> http://alaska-kamtchatka.blogspot.co.uk/2011/09/higher-order-fun.html
>
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