perl anonymous subroutine within a named subroutine

Question

Regarding below code, how does $one_sub and $two_sub become coderef's to the anonymous subroutines within named sub "sup"? The named sub isn't 'returning' those two anon subs; or is it? (at least I haven't put such a statement).

sub sup {

          my $neh = sub {
                  say "this is 'neh' subroutine"
          };

          my $hen = sub {
                  say "this is 'hen' subroutine"
         };
          ($neh, $hen);
  }

  my ($one_sub, $two_sub) = &sup;

Using Data::Dumper::Streamer show's :

$CODE1 = sub {
           use warnings;
           use strict;
           no feature;
           use feature ':5.10';
           say q[this is 'neh' subroutine];
         };
$CODE1 = sub {
           use warnings;
           use strict;
           no feature;
           use feature ':5.10';
           say q[this is 'hen' subroutine];
         };

perldoc -f return: "In the absence of an explicit return, a subroutine, eval, or do FILE automatically returns the value of the last expression evaluated." — ThisSuitIsBlackNot
– ThisSuitIsBlackNot, Commented Jun 25, 2015 at 14:25
This is one of the reasons why explicit returns are a good thing :) — Sobrique
– Sobrique, Commented Jun 25, 2015 at 14:52
Tip: Don't prefix sub calls using &. That means "ignore any prototype on the sub". Unless that's what you meant to do, of course. — ikegami
– ikegami, Commented Jun 25, 2015 at 14:59
Also makes some potentially rather interesting unexpected behaviour when you pass through and tamper with @_. — Sobrique
– Sobrique, Commented Jun 25, 2015 at 21:22

cjm · Accepted Answer · 2015-06-25 14:26:45Z

8

To quote perlsub:

If no return is found and if the last statement is an expression, its value is returned.

($neh, $hen); is an expression. In list context, its value is the 2 anonymous subs.

answered Jun 25, 2015 at 14:26

cjm

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Comments

frhack · Accepted Answer · 2015-06-25 14:27:38Z

2

Yes it is returning:

 ($neh, $hen);

In Perl the latest evaluated statement is returned. You don't need to explicitly call:

 return ($neh, $hen);

http://perldoc.perl.org/functions/return.html

answered Jun 25, 2015 at 14:27

frhack

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