Error with prototypes

[tobyink]

Migrated from rt.cpan.org #97875 (status was 'open')

Requestors:

• [email protected]

From [email protected] on 2014-08-08 12:31:35
:

On Kavorka-0.030 and Perl 5.20 (Linux debian 3.2.0-4-686-pae #1 SMP Debian 3.2.60-1+deb7u1 i686 GNU/Linux) I get the error
Variable "$x" is not available at test.pl line 17
when executing the code:
use v5.14;use warnings;use Kavorka;
my $tf = sub { 1;};
sub test (&){ $[0];}
my $a = test { my $x = $tf->(); fun(){ $x+$[0]; }};
It works if sub is used instead of fun(). I'm not sure why this particular case should fail.

[tobyink]

From [email protected] on 2017-01-31 17:53:11
:

Fun. I guess it's having trouble closing over $x for some reason.

Bizarre though because this works fine:

use v5.14;
use warnings;
use Kavorka;
sub test (&) { $[0] }
my $a = test {
my $x = 1;
fun { $x+$[0] }
};

I think in that case, $x is known to be 1, so gets optimized away within the function and is never really closed over.

It's strange though.