Select Code to Download

use strict;
use warnings;
...
    concat => sub { my $ret = foo().bar(); return $ret; },
    join   => sub { my $ret = join q{}, foo(), bar(); return $ret; },
});

use strict;
use warnings;
...
    concat => sub { my $ret = foo . bar; return $ret; },
    join   => sub { my $ret = join q{}, foo, bar; return $ret; },
});