Some sample uses: 
use ScopeSaver;
use strict;
use warnings;

our $ss;
{
  my $x = 1;
  {
    my $y = 2;
    my $z = 3;
    $ss = eval new ScopeSaver(lexical => ['$y']);
  }
  # $x doesn't need to be listed as lexical (though it would be harmle
+ss)
  # since its scope hasn't ended at this time
  $ss->scope_eval('print "x is $x\n"');

  # $y is still available because it was listed
  $ss->scope_eval('print "y is $y\n"');

  # $z is no longer available but wasn't listed to preserve
  $ss->scope_eval('print "z is ", (defined $z?$z:"undef"), "\n"');
}

{
  my $closure;

  {
    my $x = "original";
    $closure = sub { print "in $x closure\n" };
  }
  {
    my $x = "rebound";
    $ss = eval new ScopeSaver(lexical => ['$x']);
  }
  # in original closure:
  &$closure;

  # rebound closure:
  $closure = $ss->rebind($closure);
  &$closure;
}

{
  our ($x,$y) = 613..614;
  {
    my ($x,$y) = 666..667;
    $ss = eval new ScopeSaver(global => ['$x'], private => ['$y']);
  }
  # $x will be the global, not the lexical:
  $ss->scope_eval('print "x is $x\n"');

  # $y will be a freshly allocated lexical for each eval,
  # not the global or the outside lexical:
  $ss->scope_eval('print "y is ", (defined $y?$y:"undef"), "\n"');
}

[download]

In reply to Re: Rebinding closures by scope by ysth
in thread Rebinding closures by scope by ysth

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.