Re^2: Making lexically-scoped ref available to non-OO subs in another package


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Re^2: Making lexically-scoped ref available to non-OO subs in another package

by wanna_code_perl (Friar)

on Jul 12, 2013 at 13:30 UTC ( [id://1043971]=note: print w/replies, xml )

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in reply to Re: Making lexically-scoped ref available to non-OO subs in another package
in thread Making lexically-scoped ref available to non-OO subs in another package

package The::Package {
    use Carp;
    use base "Exporter";
    BEGIN { our @EXPORT = qw( my_generator foo takes_coderef ) };
    
    my $scratchpad;
    sub my_generator (&) {
        $scratchpad = {};
        shift->();
        my $tmp = $scratchpad;
        undef $scratchpad;
        return $tmp;
    }
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Just when I thought I was getting the hang of Perl..! I had no idea a my package variable would work like this.

I'm amazed at the elegance of this, and that you came up with this rather instantaneously. Thank you!

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Re^3: Making lexically-scoped ref available to non-OO subs in another package
by tobyink (Canon) on Jul 13, 2013 at 07:35 UTC

I probably wouldn't have come up with it so quickly if I hadn't been playing around with p5-mop-redux which is a prototype of a hopefully future Perl core feature. The prototype uses rather a similar technique (combined with lots of Devel::Declare magic) to provide its class-building syntax, though it uses localized package variables rather than lexicals.

(I've also done something fairly similar in Smart::Dispatch.)

package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name

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