+isChar :: Char -> Bool
+isChar c
+ | c <= '\x7f' = True
+ | otherwise = False
+
+
+isToken :: Char -> Bool
+isToken c = not (isCtl c || isSeparator c)
+
+
+listOf :: Parser a -> Parser [a]
+listOf p = do many lws
+ sepBy p (do many lws
+ char ','
+ many lws)
+
+
+token :: Parser String
+token = many1 $ satisfy isToken
+
+
+lws :: Parser String
+lws = do s <- option "" crlf
+ xs <- many1 (sp <|> ht)
+ return (s ++ xs)
+
+
+text :: Parser Char
+text = satisfy (\ c -> not (isCtl c))
+
+
+separator :: Parser Char
+separator = satisfy isSeparator
+
+
+quotedStr :: Parser String
+quotedStr = do char '"'
+ xs <- many (qdtext <|> quotedPair)
+ char '"'
+ return $ foldr (++) "" xs
+ where
+ qdtext = do c <- satisfy (/= '"')
+ return [c]
+
+ quotedPair = do q <- char '\\'
+ c <- satisfy isChar
+ return [c]