Re: Inheritance - parent of parent

Passing a partially constructed object down to the parent's constructor is very weird.

{
   package ClassA;
   ...
   sub new {
      ...
      my $self = bless({}, $class);
      $self->{...} = ...;
      return $self;
   }
   ...
}

{
   package ClassB;
   our @ISA = 'ClassA';
   sub new {
      ...
      my $self = $class->SUPER::new();
      $self->{...} = ...;
      return $self;
   }
   ...
}

{
   package ClassC;
   our @ISA = 'ClassB';
   sub new {
      ...
      my $self = $class->SUPER::new();
      $self->{...} = ...;
      return $self;
   }
   ...
}
[download]

No infinite loops, though. Not in your version or mine.

Comment on Re: Inheritance - parent of parent Download Code

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Re^2: Inheritance - parent of parent by jockel (Beadle) on Nov 23, 2007 at 08:08 UTC
Hmm.. Strange that the infinite loop don't occur.., good, but strange. I must admit that I didn't try the code above myself,, but copied the important parts from my real script, where it loops infinitly.. My assumptions about the infinite loop are because since the variable $class holds 'CLASS_C', so that calling `$class->SUPER::new();` would be the same as calling `CLASS_C->SUPER::new();` And the 'SUPER' of CLASS_C is CLASS_B, right? So, shouldn't that result in new() in CLASS_B calling itself? I've had kind of a good sleep, so now I'm going to look through my code again.. Thanks for the input so far =)	[reply] [d/l] [select]
Re^3: Inheritance - parent of parent by ikegami (Patriarch) on Nov 23, 2007 at 08:33 UTC
No, `SUPER` is based on `__PACKAGE__`, not on `ref($self)`. Quote perlobj, It is important to note that `SUPER` refers to the superclass(es) of the current package and not to the superclass(es) of the object. This is easy to demonstrate. `{ package Base; sub m { print("Boo!\n"); } } { package Child; our @ISA = 'Base'; bless({}, 'Anything')->SUPER::m(); # Boo! }` [download]	[reply] [d/l] [select]