use strict;
use warnings;

my $state = \&start;
while (my $next = $state->()) {
  $state = $next;
}

sub start {
  my %next_action = ( 1 => \&menu_1,
                           2 => \&menu_2,
                           3 => \&menu_3,
                    );

  return $next_action{$_} if exists $next_action{$_}
}