1 module Network.HTTP.Lucu.Parser
5 , parse -- Parser a -> ByteString -> (ParserResult a, ByteString)
6 , parseStr -- Parser a -> String -> (ParserResult a, ByteString)
8 , anyChar -- Parser Char
10 , allowEOF -- Parser a -> Parser a
11 , satisfy -- (Char -> Bool) -> Parser Char
12 , char -- Char -> Parser Char
13 , string -- String -> Parser String
14 , (<|>) -- Parser a -> Parser a -> Parser a
15 , oneOf -- [Char] -> Parser Char
16 , digit -- Parser Char
17 , hexDigit -- Parser Char
18 , notFollowedBy -- Parser a -> Parser ()
19 , many -- Parser a -> Parser [a]
20 , many1 -- Parser a -> Parser [a]
21 , manyTill -- Parser a -> Parser end -> Parser [a]
22 , many1Till -- Parser a -> Parser end -> Parser [a]
23 , option -- a -> Parser a -> Parser a
24 , sepBy -- Parser a -> Parser sep -> Parser [a]
25 , sepBy1 -- Parser a -> Parser sep -> Parser [a]
29 , crlf -- Parser String
34 import Control.Monad.State
35 import qualified Data.ByteString.Lazy.Char8 as B
36 import Data.ByteString.Lazy.Char8 (ByteString)
38 data Parser a = Parser {
39 runParser :: State ParserState (ParserResult a)
42 type ParserState = (ByteString, IsEOFFatal)
44 type IsEOFFatal = Bool
46 data ParserResult a = Success a
47 | IllegalInput -- 受理出來ない入力があった
48 | ReachedEOF -- 限界を越えて讀まうとした
52 -- (>>=) :: Parser a -> (a -> Parser b) -> Parser b
53 instance Monad Parser where
54 p >>= f = Parser $ do saved@(_, isEOFFatal) <- get -- 失敗した時の爲に状態を保存
57 Success a -> runParser (f a)
58 IllegalInput -> do put saved -- 状態を復歸
60 ReachedEOF -> if isEOFFatal then
65 return = Parser . return . Success
66 fail _ = Parser $ return IllegalInput
69 parse :: Parser a -> ByteString -> (ParserResult a, ByteString)
70 parse p input = let (result, (input', _)) = runState (runParser p) (input, True)
75 parseStr :: Parser a -> String -> (ParserResult a, ByteString)
76 parseStr p input = parse p $ B.pack input
79 anyChar :: Parser Char
80 anyChar = Parser $ do (input, isEOFFatal) <- get
84 do let c = B.head input
85 put (B.tail input, isEOFFatal)
90 eof = Parser $ do (input, _) <- get
97 allowEOF :: Parser a -> Parser a
98 allowEOF f = Parser $ do (input, isEOFFatal) <- get
101 result <- runParser f
104 put (input', isEOFFatal)
109 satisfy :: (Char -> Bool) -> Parser Char
110 satisfy f = do c <- anyChar
111 unless (f c) (fail "")
115 char :: Char -> Parser Char
116 char c = satisfy (== c)
119 string :: String -> Parser String
120 string str = do mapM_ char str
126 (<|>) :: Parser a -> Parser a -> Parser a
127 f <|> g = Parser $ do saved@(_, isEOFFatal) <- get -- 状態を保存
128 result <- runParser f
130 Success a -> return $ Success a
131 IllegalInput -> do put saved -- 状態を復歸
133 ReachedEOF -> if isEOFFatal then
140 oneOf :: [Char] -> Parser Char
141 oneOf = foldl (<|>) (fail "") . map char
144 notFollowedBy :: Parser a -> Parser ()
145 notFollowedBy p = p >>= fail "" <|> return ()
149 digit = do c <- anyChar
150 if c >= '0' && c <= '9' then
156 hexDigit :: Parser Char
157 hexDigit = do c <- anyChar
158 if (c >= '0' && c <= '9') ||
159 (c >= 'a' && c <= 'f') ||
160 (c >= 'A' && c <= 'F') then
166 many :: Parser a -> Parser [a]
174 many1 :: Parser a -> Parser [a]
175 many1 p = do ret <- many p
181 manyTill :: Parser a -> Parser end -> Parser [a]
182 manyTill p end = many $ do x <- p
187 many1Till :: Parser a -> Parser end -> Parser [a]
188 many1Till p end = many1 $ do x <- p
193 option :: a -> Parser a -> Parser a
194 option def p = p <|> return def
197 sepBy :: Parser a -> Parser sep -> Parser [a]
198 sepBy p sep = sepBy1 p sep <|> return []
201 sepBy1 :: Parser a -> Parser sep -> Parser [a]
202 sepBy1 p sep = do x <- p
203 xs <- many $ sep >> p
215 crlf :: Parser String
216 crlf = string "\x0d\x0a"