20040711 [CMcC]: here's a little [HTML]/[XML]/[SGML] attribute parser.  It's iterative, but it uses regexps extensively.
----
    array set match {
        quote {^([a-zA-Z0-9_-]+)[ \t]*=[ \t]*["]([^"]+)["][ \t]*(.*)$}
    	squote {^([a-zA-Z0-9_-]+)[ \t]*=[ \t]*[']([^']+)['][ \t]*(.*)$}
    	uquote {^([a-zA-Z0-9_-]+)[ \t]*=[ \t]*([^ \t'"]+)[ \t]*(.*)$} 
        }
    
    proc parseAttr {astring} {
        global match
        array set attr {}
        set astring [string trim $astring]
        if {$astring eq ""} {
    	return {}
        }
    
        while {$astring != ""} {
    	foreach m {quote squote uquote} {
    	    if {[regexp $match($m) $astring all var val suffix]} {
    		set attr($var) $val
    		set astring [string trimleft $suffix]
    	    }
    	}
        }
        return [array get attr]
    }
----
[[[Category HTML] | [Category XML]]]