class SimplePoParser::Parser

def lines

msgctxt -> msgid -> msgid_plural -> msgstr order
message parsing is always started with checking for msgctxt as content is expected in
arbitary line of a PO message. Can be comment or message 
def lines
  begin
    if @scanner.scan(/#/)
      comment
    else
      msgctxt
    end
  rescue PoSyntaxError => pe
    # throw a normal ParserError to break the recursion
    raise ParserError, "Syntax error in lines\n" + pe.message, pe.backtrace
  end
end