Re: Multiple parallel environments

[ludo@gnu.org (Ludovic Courtès)]

Peter Brett <peter@peter-b.co.uk> writes:

> ludo@gnu.org (Ludovic Courtès) writes:

[...]

>> Then you are looking for Guile's nifty first-class modules.  The module
>> API is unfortunately lightly documented (info "(guile) Module System
>> Reflection").
>
> Indeed.  Should I file a feature request for "more useful
> documentation of the Guile module system"?

You can indeed at this to the bug tracker at
http://savannah.gnu.org/bugs/?group=guile, preferably along with a
patch.  :-)

[...]

> How much will the way they work be changing in the next stable series
> of Guile releases?

There should not be any user-visible changes (you can already try out
the 1.9 releases to see by yourself).

> How will they work w.r.t. R6RS modules?

It's unclear whether R6RS module support will be part of the forthcoming
2.0 release series; Julian Graham is working on it, though.

>> What you would do is create one module for each file/project/directory:
>>
>>   (define (make-per-file-module name)
>>     (let ((m (make-module)))
>>       (set-module-name! m name) ;; give the module an optional name
>>       (beautify-user-module! m) ;; populate the module with the
>>                                 ;; default bindings
>>       m))
>
> Something like the following?
>
>   SCM
>   create_module_for_dir (char *c_path) /* Path is a UTF-8 string */
>   {
>     SCM magic = scm_from_locale_symbol ("*magic-dir-module*");
>     SCM path  = scm_from_locale_symbol (c_path);
>     SCM module = scm_resolve_module (scm_list_2 (magic, path));
>     scm_remember_upto_here_2 (magic, path);
>     return module;
>   }
>
> Not entirely sure how to emulate "beautify-user-module!" in C... any ideas?

`resolve-module' returns a new empty module (as with `make-module') if
no module of that name exist, so you really need the effect of
`beautify-user-module!'.

The best way is to invoke it:

  SCM beautify = scm_c_lookup ("beautify-user-module!");

  scm_call_1 (beautify, module);

Thanks,
Ludo'.