> (EDIT: Applied in Perl OO one gets private class-variables in package scope instead of public package variables!)

lets elaborate, in the following code you can see a simplified standard Perl class with private and public variables and methods.

The private data is only visible and accessible within the methods because of Perl's closure mechanism.

{ package TEST_CLASS; my $private_class_var; our $public_class_var; my $private_method = sub { my ($self,@args)=@_; print "-- private_method(@args)\n"; }; sub public_method { my ($self,@args)=@_; print "- public_method(@args)\n"; $self->$private_method(7..9); } sub new { my ($class,%args)=@_; bless \%args, $class; return \%args; } } my $obj = TEST_CLASS->new(a=>1,b=>2); $obj->public_method(1..3); $obj->private_method(4..6);

prints

- public_method(1 2 3) -- private_method(7 8 9) Can't locate object method "private_method" via package "TEST_CLASS" a +t /tmp/tst_pkg.pl line 32.

So, does this count as real life example?

Cheers Rolf


In reply to Re^2: Real life uses for closures. (real life?) by LanX
in thread Real life uses for closures. by BrowserUk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":



  • 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! —
  • 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:
    & &amp;
    < &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.