I was playing around with classes within Perl and trying to implement some of the patterns I've used in the past when I hit a road block. I'm still relatively new to Perl, and I can't seem to figure out what is going on here with this State pattern. 
#### a driver for the car
{ package Driver;
    sub new {
        my $class = shift;
        my $vars = {};
        $vars->{ALERTNESS} = 0;
        $vars->{STATE} = dstatenorm->new();
        bless ($vars, $class);
        return $vars; }

    sub alertness {
        my $vars = shift;
        my $state = $vars->{STATE};
        if(@_) { $vars->{ALERTNESS} = shift; }
        return $state->alertness( $vars->{ALERTNESS} ); }

    1; }

#### driver state normal
{ package dstatenorm;
    sub new {
        my $class = shift;
        my $vars = {};
        $vars->{"NAME"} = "Normal";
        bless ($vars, $class);
        return $vars; }

    sub alertness ($) {
        my $curAlertness = shift;
        return $curAlertness; }

    1; }

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When I call the "alertness" routine on the driver, I get dstatenorm=HASH(0x1832734). It looks like I'm getting close to the return I want, but I'm not sure where or how or if I have to dereference to make this work. Thanks in advance!

Update: Found it. I was shifting and the first value is the class itself. Shifting twice did the trick, so I guess I have to access @_ directly?

In reply to Implementing State pattern by Justin_BSI

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