Re: Re: Why get() and set() accessor methods are evil

[hardburn]

(Also this is not an OO issue, but merely a Perl issue.)

The example might have shown a problem specific to Perl, but the idea is applicable to any language. A Java API that returns an array of integers stored in an otherwise private field would be just as problematic.

[pg]

You are right, as Java also has primitive types.

But on the other hand, in this case, I can choose to return, for example, an ArrayList of Integer. This is much less a problem to languages that have stronger OO support.

Update:

Thanks BUU for the extension, tie was actually something I thought of. The idea of tie, actually holds some characteristics that OO interface provides.

[BUU]

So why couldn't/wouldn't you do the exact same in perl? You could even do it transparently via tie, or you could do it overtly by creating the object. Seems fairly simple to me at least.


package ArrayList;

my $i;
sub new{shift;return bless{[@_]=>shift};}

sub iterate{return $_[0]->[$i++]}

And so on and so forth.

[hardburn]

One reason you wouldn't want to is that is Perl's context-sensitivity. By using ArrayList, which would be implemented as a scalar holding a referance, you're now putting things in scalar context that really should be in list context.

BTW--Check out the Class::Iterator module for doing this.