in reply to Re^3: Tutorial: Introduction to Object-Oriented Programming
in thread Tutorial: Introduction to Object-Oriented Programming
Another issue has just come to mind. With the object attributes being keyed on "$self", which includes the name of the class, you can no longer bless an object into a sibling class to implement state transitions.
Again, I guess some people would consider this a feature. I quite like the technique myself :-)
To overcome you'll need to strip out the class name. Assuming nobody changes the output format of references in later perl versions something like this should work.
package Foo; use strict; use warnings; use overload; my %foo = (); my %self = (); # we access self enough for it to be worth caching sub self { my $self = overload::StrVal shift; return $self{$self} if exists $self{$self}; $self{$self} = substr($self, index($self, '=')+1); }; sub new { my $class = shift; bless [], $class; }; sub foo { my $self = shift->self; $foo{$self} = @_ if @_; $foo{$self}; }; sub DESTROY { my $self = shift->self; delete $foo{$self}; undef %self; };
Also, there is another advantage to Abigail-II's method. Storing the attributes in separate hashes should less expensive in memory - buckets cost less than hashes. Might make a difference if you're creating lots of objects.
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Re: Tutorial: Introduction to Object-Oriented Programming
by Abigail-II (Bishop) on Dec 13, 2002 at 11:02 UTC | |
by adrianh (Chancellor) on Dec 13, 2002 at 12:27 UTC | |
by demerphq (Chancellor) on Dec 15, 2002 at 01:45 UTC | |
by adrianh (Chancellor) on Dec 15, 2002 at 01:49 UTC |