>perl -wMstrict -le
"sub S { print 'hi ', $_[0] }
 sub T { print 'lo ', $_[0] }
 sub U { print '-- ', $_[0] }
 my %hash = (
   my $x = L => \&S,
   my $y = M => \&T,
   my $z = N => \&U,
   );
 print $x;
 $hash{$x}->($x);
 $hash{L} ->('L');
 $hash{$_}->($_) for qw(L M N);
"
L
hi L
hi L
hi L
lo M
-- N