You want to use eval(), I'd say. This is almost exactly a section of my book that I wrote last night! 
open REs, "< re_file" or die "can't read re_file: $!";
while (<REs>) {
  chomp;
  my $mode = substr($_, 0, 1, '');  # reverse-chop
  push @re, [ $mode, match_maker($_) ];
}
close REs;


# make me a match... ;)
sub match_maker {
  my $pat = shift;
  return eval qq{ sub { \$_[0] =~ $pat } };
}

[download]
If you call match_maker($foo), and $foo is '/age:\s*(\d+)/i', then the resulting function returned behaves exactly like: 
sub { $_[0] =~ /age:\s*(\d+)/i }
Now you have an array, @re, with array references holding the mode ('+' or '-') and a function you can run to match against a string. 
for (@re) {
  my ($mode, $func) = @$_;
  if ($func->($string)) {  # this is your pattern match!
    if ($mode eq '+') { print "this is ok\n"; }
    else { print "this matched an exception\n"; }
  }
}

[download]

_____________________________________________________
Jeff[japhy]Pinyan: Perl, regex, and perl hacker.
s++=END;++y(;-P)}y js++=;shajsj<++y(p-q)}?print:??;

In reply to Re: How do pack a regular expression in a variable? by japhy
in thread How do pack a regular expression in a variable? by pppaulll

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.