my $main_re = do {
    local $" = ')|)(?=.*?(';
    my @REs = map $_->{from}, @conversions;
    qr/^(?=.*?(@conversions)|)/;
};

##</code><code>##

  my @scan = $entry{$k} =~ $main_re;
  for my $i (0..$#scan) {
    next unless defined $scan[$i];
    $entry{$k} =~ s/$conversions[$i]{from}/$conversions[$i]{to}/g;
    conversions[$i]{count}++;
  }