On 27 Jan 2016 7:15 AM, Moritz Lenz wrote:
On 01/27/2016 07:17 AM, Felipe Gasper wrote:

     What is the purpose of having $! in Perl 6?

     The global variables in Perl 5 are a constant headache, prompting
us to need to local()ize variables like $@, $!, and $? to avoid
unforeseen consequences like RT #127386 and those documented in
Try::Tiny’s POD.

     Perl 6 seems to give us both the “right” and the “wrong” solution
to accessing exception variables: we get $_ within a CATCH block
(right), but we also get that global $!--which, to me, seems
pathologically wrong.

But it's not global! None of $_, $/, $! are global.

I modified the example I posted before to test that:

use v6;

my $x = 10;
my $y = 0;

my $z = $x / $y;

my $exception;
        say $z;
        CATCH {
            default {
                $exception = $_;

if ($exception) {
    say "There was an exception: $exception ($!)";

say "still running";

If you run this, $! is populated even when we’ve gone back a block level from where the exception was thrown.

So, what *is* the scoping of $!?


Reply via email to