I was reading through perlsub and perlref again on metacpan and it occurred to me creating a closure using function templates is a lot like using an anonymous subroutine, only the syntax is a little different (using local *name = sub {}; name('arg'); versus my $name = sub {}; $name->('arg');).

Is this true or am I miss understanding something? What about compile time vs runtime?

Thanks,
-Shaun

use warnings;
use v5.14;

my $y = 2014;

sub outer1
{
    my $x = $_[0] + 35;
    local *inner = sub
    {
        my $a = shift;
        local *__ANON__ = ( caller( 1 ) )[3] . "->inner";
        say( ( caller( 0 ) )[3] );
        return $y - $x * 19 + $a;
    };
    return $x + inner( $_[0] / 2 );
}

sub outer2
{
    my $x     = $_[0] + 35;
    my $inner = sub
    {
        my $a = shift;
        local *__ANON__ = ( caller( 1 ) )[3] . "->inner";
        say( ( caller( 0 ) )[3] );
        return $y - $x * 19 + $a;
    };
    return $x + $inner->( $_[0] / 2 );
}
say outer1( 8 );
say outer2( 8 );

__END__

$ perl subtest.pl
main::outer1->inner
1244
main::outer2->inner
1244

[download]

In reply to closures: anonymous subs vs function templates? by 5haun

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