^
(?:a|(?(?{ local $fuzzies = $fuzzies; !$fuzzies-- })(?=A)(?=Z)).)
(?:p|(?(?{ local $fuzzies = $fuzzies; !$fuzzies-- })(?=A)(?=Z)).)
(?:p|(?(?{ local $fuzzies = $fuzzies; !$fuzzies-- })(?=A)(?=Z)).)
(?:l|(?(?{ local $fuzzies = $fuzzies; !$fuzzies-- })(?=A)(?=Z)).)
(?:e|(?(?{ local $fuzzies = $fuzzies; !$fuzzies-- })(?=A)(?=Z)).)
(?{ $fuzzies_left = $fuzzies })
$

##</code><code>##

our $USE_A_FUZZY =
   '(?(?{ local $fuzzies = $fuzzies; !$fuzzies-- })(?=A)(?=Z))';

our $COUNT_FUZZIES_LEFT =
   '(?{ $fuzzies_left = $fuzzies })';

{
   my $string = 'apple';
   my $max_fuzzies = 2;

   my $re = '^';
   $re .= sprintf("(?:%s|${USE_A_FUZZY}.)", quotemeta($1))
      while ($string =~ /(.)/g);
   $re .= "${COUNT_FUZZIES_LEFT}\$";

   $re = do { use re 'eval'; qr/$re/ };

   our $fuzzies;
   local $fuzzies;

   our $fuzzies_left;
   local $fuzzies_left;

   while (<DATA>) {
      chomp;
      $fuzzies = $max_fuzzies;
      if (/$re/) {
         $fuzzies = $max_fuzzies - $fuzzies_left;
         if ($fuzzies) {
            print("Fuzzy match with $_ ($fuzzies fuzzies).$/");
         } else {
            print("Exact match with $_.$/");
         }
      } else {
         print("No match with $_.$/");
      }
   }
}


__DATA__
apple
arple
brple
brqle
orange


------ OUTPUT ------
Exact match with apple.
Fuzzy match with arple (1 fuzzies).
Fuzzy match with brple (2 fuzzies).
No match with brqle.
No match with orange.

##</code><code>##

^
(?:a|(?(?{!$fuzzies--})(?=A)(?=Z)).)
(?:p|(?(?{!$fuzzies--})(?=A)(?=Z)).)
(?:p|(?(?{!$fuzzies--})(?=A)(?=Z)).)
(?:l|(?(?{!$fuzzies--})(?=A)(?=Z)).)
(?:e|(?(?{!$fuzzies--})(?=A)(?=Z)).)
$

##</code><code>##

our $USE_A_FUZZY = '(?(?{!$fuzzies--})(?=A)(?=Z))';

{
   my $string = 'apple';
   my $max_fuzzies = 2;

   my $re = '^';
   $re .= sprintf("(?:%s|${USE_A_FUZZY}.)", quotemeta($1))
      while ($string =~ /(.)/g);
   $re .= "\$";

   $re = do { use re 'eval'; qr/$re/ };

   our $fuzzies;
   local $fuzzies;

   while (<DATA>) {
      chomp;
      $fuzzies = $max_fuzzies;
      if (/$re/) {
         $fuzzies = $max_fuzzies - $fuzzies;
         if ($fuzzies) {
            print("Fuzzy match with $_ ($fuzzies fuzzies).$/");
         } else {
            print("Exact match with $_.$/");
         }
      } else {
         print("No match with $_.$/");
      }
   }
}