I think you are referring to these lines from XML::Twig (taken from here)

sub new
  { my ($class, %args) = @_;
    my $handlers;

    # change all nice_perlish_names into nicePerlishNames
    %args= _normalize_args( %args);

    # check options
    unless( $args{MoreOptions})
      { foreach my $arg (keys %args)
        { carp "invalid option $arg" unless $valid_option{$arg}; }
      }
     
    # a twig is really an XML::Parser
    # my $self= XML::Parser->new(%args);
    my $self;
    $self= XML::Parser->new(%args);   

    bless $self, $class;

    #... yadda yadda

[download]

and indeed it does inherit from XML::Parser @ISA = qw(XML::Parser);

This seems to be a highly complex module also playing with UNIVERSAL so I don't feel competent to comment.

I'd say the new() method is inherited but overridden, and instead of using SUPER::new() an explicit XML::Parser->new() is used to initialize a parent object and alter it.

TIMTOWTDI !

Never used SUPER or Java so take it with a grain of salt, others with more expertise will comment soon on the basis of this post.

update

I hope it's obvious that analyzing XML::Twig is not the best way to start learning Perl's OOP. :)

Cheers Rolf

PS: Je suis Charlie!

In reply to Re^3: OOP and derived classes by LanX
in thread OOP and derived classes by Anonymous Monk

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