Beefy Boxes and Bandwidth Generously Provided by pair Networks
"be consistent"

Comment on

( #3333=superdoc: print w/replies, xml ) Need Help??

The trick here is to return a closure from a generator function. Below is a complete working example. However the salient bit is returning refs to $cont and $foo from the generator function, and dereferencing them in the caller to initialize or change them.

package Foobar; sub _setup_xforms { my ($cont, $foo); return (\$cont, \$foo, { xform1 => sub { printf("Level %d,foo=%s\n", $cont, $foo); +}, }); }; sub transform { my ($self, $cont) = @_; my ($cont_ref, $foo_ref, $xforms) = _setup_xforms(); $$cont_ref //= $cont; # //= to convince you it's not still set for my $xform (values %$xforms) { $$foo_ref //= 0; # //= as above $xform->(); $$foo_ref++; $self->transform($cont + 1) if ($cont < 5); print "Level $cont done, foo=$$foo_ref\n"; } } sub new { bless({},'Foobar') } my $foo = new Foobar( id => 1 ); $foo->transform(0);

This produces the following output:

Level 0,foo=0 Level 1,foo=0 Level 2,foo=0 Level 3,foo=0 Level 4,foo=0 Level 5,foo=0 Level 5 done, foo=1 Level 4 done, foo=1 Level 3 done, foo=1 Level 2 done, foo=1 Level 1 done, foo=1 Level 0 done, foo=1

In reply to Re: Perl OO: Need a concise way of representing operations on an object by rjt
in thread Perl OO: Need a concise way of representing operations on an object by wanna_code_perl

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, 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, 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.
  • Log In?

    What's my password?
    Create A New User
    and all is quiet...

    How do I use this? | Other CB clients
    Other Users?
    Others contemplating the Monastery: (11)
    As of 2018-01-22 21:23 GMT
    Find Nodes?
      Voting Booth?
      How did you see in the new year?

      Results (237 votes). Check out past polls.