OO-Perl Question: How to call a derived class from a base class?

BluePerl has asked for the wisdom of the Perl Monks concerning the following question:

Dear Perlmonks, I try to call a derived class from a base class. See code:

package person;
    use Method::Signatures;

    method new (%args) {
        return bless {%args}, $self;
    }
    
    method name () {
        return "*person*\n";
    }
    
    method myname () {
        return name()
    }

package eva;
    our @ISA = ("person");
    use Method::Signatures;

    method name () {
        return "eva\n";
    }

my $p = new person ();
print $p->name ();

my $e = new eva ();
print $e->name();

print $e->myname();

# returns:
# *person*
# eva
# *person*

1;
[download]

How can I achieve, that $e->myname () returns "eva". Which means, that a direved class calls its baseclass (function myname) and the baseclass should call the name function of the Child class.

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Re: OO-Perl Question: How to call a derived class from a base class? by poj (Abbot) on Jul 24, 2015 at 12:21 UTC
`method myname () { return $self->name(); }` [download] poj	[reply] [d/l]
Re^2: OO-Perl Question: How to call a derived class from a base class? by BluePerl (Acolyte) on Jul 24, 2015 at 13:20 UTC
Thanks a lot, this was what I looked for!	[reply]
Re^3: OO-Perl Question: How to call a derived class from a base class? by dsheroh (Monsignor) on Jul 25, 2015 at 08:27 UTC
Quick explanation of why that works: In Perl, an object is a reference which has been tied to a particular package (class) by `bless`ing it. When you call `$object->foo`, it executes `sub foo` from the package that `$object` has been blessed into - `package eva` if it's an `eva` object or `package person` if it's a base `person` object. When you call just plain `foo`, it executes `sub foo` from the package in which the calling code was defined. Since `myname` is defined in `package person` (and not overridden), it will always call `person::name` regardless of the object's class. If your methods used parameters or `$self`, you would have also noticed another difference: `$object->foo` implicitly passed `$object` as its first parameter (so it can be used to populate `$self`), but just plain `foo` does not. This can, obviously, cause issues if your methods use `$self` or parameters, so you should always call them as either `$object->foo` if you want them to be polymorphic or `class->foo` if you want to lock them to a specific class's implementation.	[reply] [d/l] [select]