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Date: Thu, 05 Aug 2010 18:17:25 +0200
From: Alain Frisch <alain@frisch.fr>
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To: Philippe Veber <philippe.veber@gmail.com>
Cc: Dario Teixeira <darioteixeira@yahoo.com>,
	caml-list@yquem.inria.fr
Subject: Re: [Caml-list] Emulating width subtyping with 1st-class modules
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X-Spam: no; 0.00; frisch:01 frisch:01 subtyping:01 marshaled:01 marshaling:01 simulate:01 closures:01 wrote:01 signatures:01 typing:01 caml-list:01 marshal:01 alain:01 alain:01 data:02 

On 08/05/2010 06:10 PM, Philippe Veber wrote:
> I have a related question: the only reason why i'm not fully happy with
> objects used as anonymous records is that i sometimes use them as mere
> data containers and need to save (marshal) them at some point. Which is
> not permitted as soon as you want to exchange marshalled values between
> two different programs. Hopefully one can rely on json-static to cope
> with that limitation in a quite elegant way. Are first-class modules
> distinct in that respect ? That is, can they be marshalled if they do
> not contain closures ?

Yes, they can be marshaled. As usual with marshaling, you don't get any 
type safety.

That said, first-class modules cannot really be used to simulate 
anonymous records since they rely on nominal typing: even if S and S' 
refer to identical signatures, the types (module S) and (module S') are 
not equal.


Alain