Re^2: Inheritance - calling parent constructor

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Re^3: Inheritance - calling parent constructor by kennethk (Abbot) on Dec 29, 2009 at 18:52 UTC
The difference between hard-coding `Parent->` as opposed to invoking `SUPER` is relevant when you have multiple levels of inheritance. If you created a Grandchild, a method using SUPER would climb the `@ISA` tree to resolve `new`, whereas hard-coding `Parent->` will go straight there. It's also useful for code reuse, since SUPER is not package specific. For example, if you had a series of validation routines, you could open `sub validate {` with `my $self = shift; $self->SUPER::validate();` and it would crawl the inheritance tree correctly without refactoring and the associated fagility. You would only need to define a constructor in the child object if it requires additional functionality - in this case, because Child has an additional property. If you are interested in all this or rolling your own OO, a read read through of perlboot and perltoot is merited.	[reply] [d/l] [select]
Re^3: Inheritance - calling parent constructor by ikegami (Patriarch) on Dec 29, 2009 at 23:13 UTC
You could use `my $self = $class->Parent::new(...);` [download] instead of `my $self = $class->SUPER::new(...);` [download] And you might even have to in some weird situations (although `use mro 'c3';` would probably be a better fix). But using `Parent` is redundant. You already specified it's the parent class. To use it here is to needlessly hardcode a value. Nothing good can come of that.	[reply] [d/l] [select]