It's a little hard to know what you mean, but if you want Object A to call a method on Object B and have B know that A was the object that called it, then you can just pass A as an argument. In other words, you define a consistent API where the @_ array always contains self and the calling object. 

sub foo {
  my ($self, $caller, @targets) = @_;

  for my $obj ( @targets ) {
    $obj->bar($self, ... );
  }
}

sub bar {
  my ($self, $caller, @args) = @_;

  ...
}

[download]

The examples above don't do anything with $caller, but you can see how $self is included as an argument to the bar method call.

For a real-world example of this kind of thing, look at POE, which defines array-offset constants to pick out specific objects that are always passed as arguments. For example:

  sub handle_event {
    my ($kernel, $heap, $parameter) = @_[KERNEL, HEAP, ARG0];
    ...;
  }

[download]

It seems a little clunky at first glance, but when used consistently across all POE modules, it actually starts seeming elegant.

-xdg

Code written by xdg and posted on PerlMonks is public domain. It is provided as is with no warranties, express or implied, of any kind. Posted code may not have been tested. Use of posted code is at your own risk.

In reply to Re: A caller() by any other name by xdg
in thread A caller() by any other name by Bloodnok

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.