sub foo {
   my ($x) = @_;
  '' =~ /(?{ print "$x\n" })/;
} 

foo('a');
foo('b');

##</code><code>##

Variable "$x" will not stay shared at (re_eval 1) line 2.
a
a

##</code><code>##

   local our @common_letters;
   local our @wordsCopy = @words;