Hi Shayne,

One approach is to name the *output* signature of the functors:

module type EQ_PROD_S = sig
    module X : EQ
    module Y : EQ
    type t = X.t * Y.t
    val eq: t * t -> bool
end

module type EQ_PROD = functor (X : EQ) (Y : EQ) ->
    EQ_PROD_S with module X := X and module Y := Y

module type ORD_PROD_S = sig
    include EQ_PROD_S
    val lt : t * t -> bool
end

module type LT_PROD = functor (X : EQ) (Y : EQ) ->
    LT_PROD_S with module X := X and module Y := Y

etc.

Cheers,
Nicolas



On Fri, Oct 28, 2016 at 2:44 PM, Shayne Fletcher <
shayne.fletcher.50@gmail.com> wrote:

> If one wants to include a functor signature in another...
>
> module type EQ = sig
>   type t
>   val eq : t * t -> bool
> end
>
> module type EQ_PROD = functor (X : EQ) (Y : EQ) ->
> sig
>     type t = X.t * Y.t
>     val eq : t * t -> bool
>   end
>
> module type ORD = sig
>   include EQ
>   val lt : t * t -> bool
> end
>
> module type LT_PROD = functor (X : EQ) (Y : EQ) ->
> sig
>   include EQ_PROD (*What do I say here?*)
> end
>
> ​... How does one do that? Is there a syntax for this sort of thing?​
>
> --
> Shayne Fletcher
>