You are using two techniques. I don't know which you are asking about.

• You are using closures to privatise attributes. (Contrary to what others have said, you don't have "a closure". Each of your methods are closures.) I don't know if using closures for this purpose has a name.

• You have per-object methods instead of classes. JavaScript uses this. It's called Prototype-based programming. Except you don't actually support prototypes.

By the way, why create %internal at all?

sub new_counter {
    my ($start) = @_;

    my $count = $start;

    return {
        add => sub {
            my ($value) = @_;
            $count += $value;
        },

        get => sub {
            return $count;
        },
    };
}
[download]

Or even

sub new_counter {
    my ($count) = @_;

    ...
}
[download]

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.