Re: [Caml-list] first class modules: differences in 3.12 vs 3.13?

[Dmitry Bely <dmitry.bely@gmail.com>]

On Wed, Mar 30, 2011 at 12:59 PM, Anders Fugmann <anders@fugmann.net> wrote:
> Hi Dmitry,
>
> On 03/30/2011 10:02 AM, Dmitry Bely wrote:
>>
>> On Wed, Mar 30, 2011 at 11:57 AM, Joel Reymont<joelr1@gmail.com>  wrote:
>>>
>>> I get an error on this with 3.12 but no error with 3.13.0+dev2
>>> (2010-10-22).
>>>
>>> let _ = Simple.main (module Client) (module Server) (module Config)
>>>
>>> Why? I thought 3.12 supported first-class modules.
>>
>> I believe module types are a must:
>>
>> let _ = Simple.main (module Client : CLIENT) (module Server : SERVER)
>> (module Config : CONFIG)
>
> I tried this using 3.12, and the compiler now complains that:
> Error: Unbound module type CLIENT
>
> (I'm using the same code base as Joel Reymont)
>
> If the names in capital letters just arbitrary names?

Of course, you should define it first:

module type CLIENT =
sig
...
end

In your case

module type CLIENT =
sig
  include module type of Client
end

will probably be sufficient. For more information on module types see
chapter 6.10 of the OCaml user's manual.

- Dmitry Bely