Hofmator has asked for the wisdom of the Perl Monks concerning the following question:

I'm a bit surprised by the behaviour of the following code:
use strict; use warnings; my %h = (1=>2, 3=>4); sub say { print @_, $/ }; sub get_keys { print 'called:'; if (wantarray()) { print 'array:'; } else { print defined wantarray() ? 'scalar' : 'void'; } return keys %h; } # Output: say sort get_keys; # get_keys say sort get_keys(); # say sort &get_keys; # called:array:13 say sort &get_keys(); # called:array:13 say sort @{[get_keys]}; # called:array:13 say sort @{[get_keys()]}; # called:array:13

I would have expected that all these outputs would be identical. Here my guesses what went wrong. Could somebody shed some more light on it, please.

In case it matters: This is perl, v5.6.1 built for i386-linux.

And btw, I came across this when I tested App::Ack (Version 1.50) and tried to run ack --help types which doesn't display any types for me. Tracking it down, I reached the following line in App::Ack::show_help_types, which exhibits the behaviour of case 2 above.

for my $type ( sort( filetypes_supported() ) ) {

-- Hofmator

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