Re^2: kind of effort required for learning OO perl ?!

[chromatic]

I can't recommend some of this advice; it looks prone to making messes.

package dog;

Lowercase module names are, by convention, pragmas.

    return(bless(dog->new(),$class));

Why double bless? If the parent constructor is at all sane, it allows subclassing.

my $doggie = new cockerSpaniel();

The indirect method invocation syntax is fraught with peril; it's ambiguous to parse and Perl occasionally guesses incorrectly depending on the compilation order of your code.

Also inheritance is not an essential part of object orientation. Arguably neither is encapsulation.

You're absolutely right about object design being important. Most tutorials never teach that, and it's vital to writing effective OO.

[InfiniteSilence]

What double bless...are you referring to this:

sub new {
    my ($class) = @_;
    return(bless(dog->new(),$class));
}

?

I borrowed this syntax from the perlbot example:

            sub new {
                    my $type = shift;
                    my $self = Bar->new;
                    $self->{'biz'} = 11;
                    bless $self, $type;
            }

When I checked that $self reference was indeed blessed before it was passed through bless again:

  DB<3> p UNIVERSAL::isa($self,'Bar');
1

What is the harm?

[chromatic]

What does dog->new() return? If you didn't have any new() defined in Bar, what would Bar->new() return?

I borrowed this syntax from the perlbot example

Thanks. I'll submit a patch to fix that example code.