# lexing
while token_type is not eof
if(token_type)=begincomment
inbegincomment = true
if(token_type=endcomment
if incomment
inbegincomment = false
if incomment
style = commentstyle
else
style = stylemap.getstyle
drawlines with the style
# lexing is done
if still in begincomment
lexer the rest of the document until the ending comment is found applying the comment style
if was in endcomment with no matching begincomment
lexer the document until the beginning until a begincomment is found applying an error style or a comment style