#!/usr/bin/perl

use warnings;
use strict;
use HTML::TokeParser::Simple;

my $html;
{
	local $/;
	$html = <DATA>
}

my @stack;
my %lookup = (
	'font-weight: bold;' => 'b',
	'font-style: italic;' => 'i',
	'text-decoration: underline;' => 'u',
);

my $tp = HTML::TokeParser::Simple->new(\$html);

while (my $t = $tp->get_token){
	
	if ($t->is_start_tag('span')){
		my $attr = $t->get_attr('style');
		my $tag = $lookup{$attr};
		push @stack, $tag;
		print "<$tag>";
		next;
	}
	
	if ($t->is_end_tag('span')){
		my $tag = pop @stack;
		print "</$tag>";
		next;
	}
	
	print $t->as_is;
	
}

__DATA__
this <span style="font-weight: bold;">is</span> some
<span style="font-weight: bold;">test
  <span style="font-style: italic;">text</span>
  <span style="text-decoration: underline;">for</span> bolding</span>, 
  underlining and italicizing text.<br />

##</code><code>##

---------- Capture Output ----------
> "c:\perl\bin\perl.exe" _new.pl
this <b>is</b> some
<b>test
  <i>text</i>
  <u>for</u> bolding</b>, 
  underlining and italicizing text.<br />

> Terminated with exit code 0.