comment on

Closures are like objects, but with only one method. Here is a way that sort of gets around that limitation. This example is pretty bland, but you get the idea (exchange keys for methods).

If you prefer $object->{method}() syntax, you can use a hash reference instead of hash.
my $object = {};
%$object = constructor();

#!/usr/bin/perl -w
use strict;

my %object = constructor();

$object{save}->('name' => 'smith');

print $object{count}->(), $/;

my $name = $object{lookup}->('name');

$object{delete}->('name');

print $object{count}->(), $/;

print "My name is $name\n";

sub constructor {
    my %object;
    return 
        'save' => sub {
            my ($key, $val) = @_;
            die "save method requires two parameters" if ! defined $va
+l;
            $object{$key} = $val;
            return;
        },
        'delete' => sub {
            my $key = shift;
            return delete $object{$key};
        },
        'lookup' => sub {
            my $key = shift;
            return $object{$key};
        },
        'count' => sub {          
            return scalar keys %object;
        }
}
[download]

In reply to Multi-Method closures by Limbic~Region

Are you posting in the right place? Check out Where do I post X? to know for sure.
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
Want more info? How to link or How to display code and escape characters are good places to start.


Pathologically Eclectic Rubbish Lister
	PerlMonks