This just seems like a fancy wrapper to $instance->{attribute} notation. Yeah, you can make assignments to more complicated things, but you can do that with overload as well. I guess I just don't get it.

I've fallen in the habit of implementing this type of thing for set and get operations: 

package SomePackage;
use base 'Class::Base';

## super-simple 'new'
sub new {
   my $self = shift;
   bless { one => 1, two => 2 }, $self;
}

sub set {
   my $self   = shift;
   my $attrib = shift;
   return $self->error("No such attribute '$attrib'") 
      unless exists $self->{$attrib}
   
   my $value = shift;
   # check to make sure we're setting the same kind of reference, if i
+t matters
   if (ref $self->{$attrib} && ref $value ne ref $self->{$attrib}) {
      return $self->error("Reference types do not match for '$attrib' 
+set.")
   }

   $self->{$attrib} = $value;
   return 1; # true on success   
}

sub get {
   my ($self, $attrib) = @_;
   return $self->error("Attribute '$attrib' doesn't exist")
     unless exists $self->{$attrib};
   
   my $value = $self->{$attrib};
   return $value;
}

1;

[download]

This means I can do $instance->set('one', 'Hey there!'); and $instance->get('two');. If certain attributes have special rules to validate data, I can deal with those by altering 'set' slightly. For example: 

# set from above gets renamed _set_DEFAULT

sub set {
   my ($self, $attrib, $value) = @_;
   if ( $self->can('_set_'.$attrib) ) {
      my $result;
      eval "\$result = \$self->_set_$attrib($value)";
      return $result;
   }
   else {
      return $self->_set_DEFAULT($attrib, $value);
   }
}

[download]

Something like that is much cleaner and clearer in the implmentation. I like the idea that when I see $instance->{attrib} = 2, I know the code is messing about with something advanced, while $instance->set('attrib', 2) is playing by the rules.

Besides, with Perl6's advancements in lvalue subs, it will be possible to do something like $instance->accessor('attrib') = 2, and we both win, so I don't see much point in debating the tie methodology.

<-radiant.matrix->
A collection of thoughts and links from the minds of geeks
The Code that can be seen is not the true Code
"In any sufficiently large group of people, most are idiots" - Kaa's Law

In reply to Re: tie for Perlish, encapsulated objects by radiantmatrix
in thread tie for Perlish, encapsulated objects by Roy Johnson

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