[ocaml-platform] on the need and design of OCaml namespaces

[Christophe TROESTLER]

On Fri, 22 Feb 2013 11:41:10 +0000, Anil Madhavapeddy wrote:
>
> There's one scenario which absolutely requires the ability to 
> explicitly open a particular namespace: camlp4 code generation.
>
> Right now, several camlp4 extensions break because they use modules 
> from the standard Pervasives library, and have no way to explicitly 
> state that.  If Core.Std is opened, then compilation fails.
>
> The two workarounds are:
> - hack the build system to pass -pp options to the camlp4 
> generator. Painful.
> - have some facility to explicitly open 'Caml_std' or 'Core_std' 
> locally, irrespective of the current module environment.
>
> I believe namespaces addresses the latter workaround.

Camlp4 can insert some code to alias the standard modules needed by 
code generation at the beginning of the source files (not foolproof 
because a name needs to be generated but good enough in practice).  
It would be better if that facility was provided by a Camlp4 module 
instead of needing to be redone by each extension.