sub forth_draft {
    my %xlist = map{ split('\/', $_) } split(',', $match_list);

    $attrs =~ s/\A$tag //; # clean up
    for (split (' (?=\w+\=)', $attrs)) {
     my ($name, $value) = split('=');
     # little more golfing action
     (defined $xlist{$name} && $markup =~ s/X\{$name\}/$value/g)
      ? $xlist{$name} = undef # this exists now
      : $markup = '' if $markup; # do this and let it run through, faster.
      last if !$markup; # with out this it drops speed now?
     }

     # not in Benchmark
#     $markup
#     ? print $markup
#     : print 'nope';
}

##</code><code>##

Benchmark: running a_first_draft, b_second_draft, c_third_draft, d_forth_draft for at least 1 CPU seconds...
a_first_draft:  1 wallclock secs ( 1.05 usr +  0.00 sys =  1.05 CPU) @ 29132.76/s (n=30502)
b_second_draft:  1 wallclock secs ( 1.09 usr +  0.00 sys =  1.09 CPU) @ 31449.73/s (n=34406)
c_third_draft:  1 wallclock secs ( 1.11 usr +  0.00 sys =  1.11 CPU) @ 35255.18/s (n=39098)
d_forth_draft:  1 wallclock secs ( 1.06 usr +  0.00 sys =  1.06 CPU) @ 115597.37/s (n=122880)