def step
start_group :normal, matched if scan( /\s+/ )
if @in_tag
case
when scan( /([-\w]+):([-\w]+)/ )
start_group :namespace, subgroup(1)
start_group :punct, ":"
start_group :attribute, subgroup(2)
when scan( /\d+/ )
start_group :number, matched
when scan( /[-\w]+/ )
start_group :attribute, matched
when scan( %r{[/?]?>} )
@in_tag = false
start_group :punct, matched
when scan( /=/ )
start_group :punct, matched
when scan( /["']/ )
scan_string matched
else
append getch
end
elsif ( text = scan_until( /(?=[<&])/ ) )
start_group :normal, text unless text.empty?
if scan(/<!--.*?(-->|\Z)/m)
start_group :comment, matched
else
case peek(1)
when "<"
start_group :punct, getch
case peek(1)
when "?"
append getch
when "/"
append getch
when "!"
append getch
end
start_group :normal, matched if scan( /\s+/ )
if scan( /([-\w]+):([-\w]+)/ )
start_group :namespace, subgroup(1)
start_group :punct, ":"
start_group :tag, subgroup(2)
elsif scan( /[-\w]+/ )
start_group :tag, matched
end
@in_tag = true
when "&"
if scan( /&\S{1,10};/ )
start_group :entity, matched
else
start_group :normal, scan( /&/ )
end
end
end
else
append scan_until( /\Z/ )
end
end