use strict;
use warnings;

my @keys = qw{ A B C D };
my( $k, $v );

print q{-} x 20, qq{\n};

my $hashref = sub { return { map { $_, shift } @keys } }->( 1 .. 4 );

print qq{  Keys: @{ [ keys %{ $hashref } ] }\n};
print qq{Values: @{ [ values %{ $hashref } ] }\n};

print qq{  Each:\n};
print qq{        $k => $v\n} while ( $k, $v ) = each %{ $hashref };

print q{-} x 20, qq{\n};

print qq{  Keys: @{ [
   keys %{ sub { return { map { $_, shift } @keys } }->( 1 .. 4 ) }
   ] }\n};
print qq{Values: @{ [
   values %{ sub { return { map { $_, shift } @keys } }->( 1 .. 4 ) }
   ] }\n};

print qq{  Each:\n};
my $count = 0;
while( ( $k, $v ) =
   each %{ sub { return { map { $_, shift } @keys } }->( 1 .. 4 ) }
   )
{
    last if ++ $count > 5;
    print qq{        $k => $v\n};
}

print q{-} x 20, qq{\n};

##</code><code>##

--------------------
  Keys: A D C B
Values: 1 4 3 2
  Each:
        A => 1
        D => 4
        C => 3
        B => 2
--------------------
  Keys: A D C B
Values: 1 4 3 2
  Each:
        A => 1
        A => 1
        A => 1
        A => 1
        A => 1
--------------------