At 12:06 PM +0800 5/25/05, Autrijus Tang wrote:
So, this now works in Pugs with (with a "env PUGS_EMBED=perl5" build):
use Digest--perl5;
my $cxt = Digest.SHA1;
$cxt.add('Pugs!');
# This prints: 66db83c4c3953949a30563141f08a848c4202f7f
say $cxt.hexdigest;
This includes the "Digest.pm" from Perl 5. DBI.pm, CGI.pm etc will
also work.
Now my question is, is my choice of using the "perl5" namespace indicator a
sane way to handle this? Is it okay for Perl 6 to fallback to using Perl 5
automatically? Or should I use something else than "use" entirely?
Thanks,
/Autrijus/
I would say that one should always have to specify the Perl 5
namespace in some way, so that there are no surprises as to whether
something you invoke is implemented in Perl 6 or Perl 5, and so that
it is possible to be actively using a Perl 5 and Perl 6 module with
the same short name at the same time.
Do not fallback to it automatically.
Rather, if someone wanted to not fill their Perl 6 code with
"--perl5", they should use the Perl 6 feature that lets you create
lexical aliases to things; they can explicitly declare a Perl 6 name
for what they want to use, which just so happens to be an alias for
the Perl 5 implementation.
I won't suggest exact syntax here, though yours looks fine for now.
Separately, since this together with the earlier 'inline' feature for
Perl 5 sort of completes a circle of Pugs->Perl5->Pugs or
Perl5->Pugs->Perl5, I see a further improvement that could possibly
be made, if it isn't already.
That is, when you have three-somes like that, let the two endmost
Pugs, or endmost Perl5, be the exact same interpreter in memory. So
that, eg, if you set a global var in the caller-most Perl5, it will
be visible in the called-most Perl5, or vice-versa.
On the other hand, I don't know whether or not that would be better
in practice than keeping separate interpreters for calling and called.
-- Darren Duncan
