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 , count -- Int -> Parser a -> Parser [a]
24 , option -- a -> Parser a -> Parser a
25 , sepBy -- Parser a -> Parser sep -> Parser [a]
26 , sepBy1 -- Parser a -> Parser sep -> Parser [a]
30 , crlf -- Parser String
35 import Control.Monad.State
36 import qualified Data.ByteString.Lazy.Char8 as B
37 import Data.ByteString.Lazy.Char8 (ByteString)
39 data Parser a = Parser {
40 runParser :: State ParserState (ParserResult a)
43 type ParserState = (ByteString, IsEOFFatal)
45 type IsEOFFatal = Bool
47 data ParserResult a = Success a
48 | IllegalInput -- 受理出來ない入力があった
49 | ReachedEOF -- 限界を越えて讀まうとした
53 -- (>>=) :: Parser a -> (a -> Parser b) -> Parser b
54 instance Monad Parser where
55 p >>= f = Parser $ do saved@(_, isEOFFatal) <- get -- 失敗した時の爲に状態を保存
58 Success a -> runParser (f a)
59 IllegalInput -> do put saved -- 状態を復歸
61 ReachedEOF -> if isEOFFatal then
66 return = Parser . return . Success
67 fail _ = Parser $ return IllegalInput
70 parse :: Parser a -> ByteString -> (ParserResult a, ByteString)
71 parse p input = let (result, (input', _)) = runState (runParser p) (input, True)
76 parseStr :: Parser a -> String -> (ParserResult a, ByteString)
77 parseStr p input = parse p $ B.pack input
80 anyChar :: Parser Char
81 anyChar = Parser $ do (input, isEOFFatal) <- get
85 do let c = B.head input
86 put (B.tail input, isEOFFatal)
91 eof = Parser $ do (input, _) <- get
98 allowEOF :: Parser a -> Parser a
99 allowEOF f = Parser $ do (input, isEOFFatal) <- get
102 result <- runParser f
105 put (input', isEOFFatal)
110 satisfy :: (Char -> Bool) -> Parser Char
111 satisfy f = do c <- anyChar
112 unless (f c) (fail "")
116 char :: Char -> Parser Char
117 char c = satisfy (== c)
120 string :: String -> Parser String
121 string str = do mapM_ char str
127 (<|>) :: Parser a -> Parser a -> Parser a
128 f <|> g = Parser $ do saved@(_, isEOFFatal) <- get -- 状態を保存
129 result <- runParser f
131 Success a -> return $ Success a
132 IllegalInput -> do put saved -- 状態を復歸
134 ReachedEOF -> if isEOFFatal then
141 oneOf :: [Char] -> Parser Char
142 oneOf = foldl (<|>) (fail "") . map char
145 notFollowedBy :: Parser a -> Parser ()
146 notFollowedBy p = p >>= fail "" <|> return ()
150 digit = do c <- anyChar
151 if c >= '0' && c <= '9' then
157 hexDigit :: Parser Char
158 hexDigit = do c <- anyChar
159 if (c >= '0' && c <= '9') ||
160 (c >= 'a' && c <= 'f') ||
161 (c >= 'A' && c <= 'F') then
167 many :: Parser a -> Parser [a]
175 many1 :: Parser a -> Parser [a]
176 many1 p = do ret <- many p
182 manyTill :: Parser a -> Parser end -> Parser [a]
183 manyTill p end = many $ do x <- p
188 many1Till :: Parser a -> Parser end -> Parser [a]
189 many1Till p end = many1 $ do x <- p
194 count :: Int -> Parser a -> Parser [a]
195 count 0 _ = return []
196 count n p = do x <- p
201 option :: a -> Parser a -> Parser a
202 option def p = p <|> return def
205 sepBy :: Parser a -> Parser sep -> Parser [a]
206 sepBy p sep = sepBy1 p sep <|> return []
209 sepBy1 :: Parser a -> Parser sep -> Parser [a]
210 sepBy1 p sep = do x <- p
211 xs <- many $ sep >> p
223 crlf :: Parser String
224 crlf = string "\x0d\x0a"