I see three possible solutions to this:
  1. 1) Save the value in another variable, using Readonly if you want to ensure the saved value doesn't get modified.
  2. 2) Use a closure.
  3. 3) Interpolate the variable in an eval'd anonymous subroutine.
use Readonly;

my $str = 'hi';

# String
Readonly my $STR => $str;

# Closure
my $closure = do { my $var = $str; sub { $var } };

# Evalled Sub
my $anonsub = do {
    (my $var = $str) =~ s/(["\\])/\\$1/g;
    eval qq{sub {"$var"}};
};

$str = 'hello';

print "string = $STR\n";
print "closure = ", $closure->(), "\n";
print "anonsub = ", $anonsub->(), "\n";

[download]

In reply to Re: simple anonymous subroutine and variable interpolation timing question by wind
in thread simple anonymous subroutine and variable interpolation timing question by tj_thompson

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.