On Thu, Mar 02, 2006 at 15:13:07 +0200, Zohar Kelrich wrote:
> We were discussing some confusing macro behaviours, when we came upon  this 
> curious thing. This code is really simple in p5, as it doesn't  really have 
> separate compilation, but in p6, the modules can be pre- compiled or cached.
> 8<--
>       module ImportHeadache;
>       my $m;
>       sub import() {
>               $m++;
>       }
>       sub report is export { $m };
>       sub deport {...}
> #-- Meanwhile, elsewhere!
>       module Elsewhere;
>       use ImportHeadache; # I'm calling import at Elsewhere's compile time!
> #-- Meanwhile, another elsewhere!
>       module Elsewhere2;
>       use ImportHeadache; # I'm calling import at Elsewhere2's compile time!
> #-- Main program
>       use v6;
>       use Elsewhere;
>       use Elsewhere2;
>       use ImportHeadache;
>       say report; # What should I say?
> -->8
> The result is, of course, (1..3).pick(), depending on whether the  modules 
> were compiled by the same compiler instance at the same time.

Perl 6 is specced such that it's always separate compilation, so
this should probably always be 0, unless you're tying the value to

The way it's handled:

$m is reallocated every time a module is used, and thrown away after
it finished compiling.

Then the resulting code will be linked, after $m was garbage
collected. This code can be relinked as many times as we want.

> The problem seems to be that we have statefulness that we expect to  survive 
> compilation boundaries.

Well, Perl 5 didn't have such boundries =)

All statefulness in Perl 6 is not saved. Values and code are
dumoped, and will be loaded on every link. This means that this does
not get saved back to disk. This also means that linkage could be

> So, should each compilation unit get a fresh environment?  Or should  this 
> simply work like I think it currently does, and just hopefully  not bite 
> people 
> too often? Should doing what this is trying to do be  possible in a 
> different, longer-huffmanized way?

I think separate compilation is more consistent - it allows much

 ()  Yuval Kogman <[EMAIL PROTECTED]> 0xEBD27418  perl hacker &
 /\  kung foo master: /me tips over a cow: neeyah!!!!!!!!!!!!!!!!!!!!!!

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