"Tim Bunce" <[EMAIL PROTECTED]> wrote:
Having said all that, I don't think it's worth worrying about
inter-language issues until more fundamental namespace co-existance
issues are more settled.
Will a Python module clash with a Perl6 module of the same name?
(That way lies insanity so I certainly hope not.)
If not then separate namespace hierarchies are required.
The most natural way to do that is to give each HLL its own
'virtual root' near the top of a shared namespace hierarchy.
It seems to me that this would mean that to use a module we always have to
care about what language it is written in. Yes, I agree that we don't want
clashes and it's for sure that some languages we support will have clashing
name spaces even in their standard libraries. So something like what is
suggested here is very much needed.
At the same time, glancing at the .NET platform, if I remember correctly you
don't have to care what language another class was implemented in to use
it - you just go ahead and use it - which is nice. (It means, for example,
that the Perl 5 module that a Python program was using, on conversion to
Perl 6, doesn't break the Python program because it's still looking in the
Perl 5 namespace.) There is a shared namespace between all .NET languages.
That alone can't work for what we're doing as we'd get clashes, but I think
it's got some nice properties.
Is there a happy medium here? Perhaps (jumping to P6 syntax, but hopefully
you get the idea):-
use perl5:What::Ever; # Only look in the Perl 5 namespace.
use perl6:What::Ever; # Only look in the Perl 6 namespace.
use What::Ever; # Look in any name space.
But maybe "look everywhere by default" is the wrong behaviour and could
create all kinds of confusion. So maybe (assuming we're writing in P6):-
use perl5:What::Ever; # Only look in the Perl 5 namespace.
use What::Ever; # Only look in the Perl 6 namespace.
use *:What::Ever; # Look in any name space - not sure * will work
though.
That way, projects can implement classes/subs/whatever in any language under
a language-independent MyProject namespace and have things work out as they
wish, while the default is each language functioning in its own namespace.
I can think some stuff up on a Parrot level for this, if anyone believes
this idea worth considering.
Jonathan
