I am currently writing a large-ish set of classes, with a decent amount of inherritence and other shennanigans going on. For the first time, I am going to enforce strict OO standards by hiding my class data and using closures for accessors, as suggested on perltooc. So I have something like this set up: 

package My::Class;
use strict;
use warnings;

{ 
    # hide from the rest of the class
    my %CLASSDATA = ( foo => 1, bar => 2, baz => 3 );

    # install generic accessor/mutator methods
    no strict 'refs';
    for my $key(keys %CLASSDATA) { 
        *$key = sub { shift; 
                      $CLASSDATA{$key} = shift if @_; 
                      return $CLASSDATA{$key}; 
                     };
    }
    use strict 'refs';
}

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This works great, and allows me to inherrit and/or override the class data in subclasses.

But now, I want to do the same thing for instance data. (I don't need to inherrit instance data, I just want to protect it.) Of course, I can't simply install more closure subs in the constructor, because then each instance would re-define the subs from the previous ones. I don't want to store the instance data in the blessed reference, because that would allow direct access to it.

I thought about doing something like AUTOLOAD with closures, but that doesn't seem like a great solution. Any ideas would be appreciated! Thanks,

-Mike

In reply to Ironclad protection of instance data by friedo

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