sub search_and_replace {
  open my $target_file, "<", $_;
  my $filename = path($_);
  my $pos = 0;
  my $more = 1;
  while( $more )
  {
    $filename->edit( sub 
    {
      pos($_) = $pos;
      if( /$match/g )
        {
          my ( $was, $where, $pre, $post ) = ( $1, $-[1], $`, $');
          print "\n", $pre =~ s/^.*\n(?=.*\n)//sr, "$old$was$reset",
            $post =~ s/\n.*?\n\K.*//sr, "\n";
          my $replace = ask( $was );
          $was eq $replace or substr $_, $where, length $was, $replace;
          $pos = $where + length $replace;
        }
        else { $more = 0 }
      } );
      # print "\e[33m", $target_file->slurp, "\e[0m"; # FIXME here for testing
    }
    close $target_file;
}