Re: [Caml-list] Nesting Modules

[Richard Jones <rich@annexia.org>]

On Wed, Nov 02, 2005 at 11:57:45AM +0100, Daniel Bünzli wrote:
> Le 2 nov. 05 à 11:47, Richard Jones a écrit :
> > consider a database layer:
> >
> >  Database
> >  Database_Postgres
> >  Database_MySQL
> >
> >Obviously '_' is the way to go here if you want multiple third parties
> >to provide database modules.  'include' wouldn't work at all here.
> 
> You are right. I think 'include' doesn't work here because there is a  
> notion of choice. If I understand well your example, functors  
> wouldn't help here because it is not that you want to get a unified  
> interface (frontend) from a specific database implementation  
> (backend), but you really want to access database specific features  
> via the third party modules, right ?

Yes; I'm really comparing it to Perl's modules.  In Perl's module
repository, CPAN, they have a zillion modules and so need to name them
sensibly and hierarchically.  For example under "Net"[1] you have
"Net::DHCP", "Net::Daemon", "Net::FTP", etc...  There is no way to
"open Net" (or its equivalent) in Perl - this is just a useful way to
organise modules.

May not be applicable to OCaml of course.

Rich.

[1] http://www.cpan.org/modules/by-module/Net/

-- 
Richard Jones, CTO Merjis Ltd.
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