+{-# LANGUAGE
+ BangPatterns
+ , ScopedTypeVariables
+ , UnicodeSyntax
+ #-}
+-- |This is an auxiliary parser utilities. You usually don't have to
+-- use this module directly.
module Network.HTTP.Lucu.Parser
- ( Parser(..)
- , parse -- Parser a -> ByteString -> Maybe (a, ByteString)
- , anyChar -- Parser Char
- , satisfy -- (Char -> Bool) -> Parser Char
- , char -- Char -> Parser Char
- , string -- String -> Parser String
- , (<|>) -- Parser a -> Parser a -> Parser a
- , oneOf -- [Char] -> Parser Char
- , digit -- Parser Char
- , notFollowedBy -- Parser a -> Parser ()
- , many -- Parser a -> Parser [a]
- , many1 -- Parser a -> Parser [a]
- , manyTill -- Parser a -> Parser end -> Parser [a]
- , many1Till -- Parser a -> Parser end -> Parser [a]
- , option -- a -> Parser a -> Parser a
- , sp -- Parser Char
- , ht -- Parser Char
- , crlf -- Parser String
+ ( atMost
+ , manyOctetsTill
)
where
-
-import Control.Monad
-import Control.Monad.State
-import qualified Data.ByteString.Lazy.Char8 as B
-import Data.ByteString.Lazy.Char8 (ByteString)
-
-data Parser a = Parser {
- runParser :: State ByteString (Maybe a)
- }
-
-
--- (>>=) :: Parser a -> (a -> Parser b) -> Parser b
-instance Monad Parser where
- p >>= f = Parser $ do saved <- get -- 失敗した時の爲に状態を保存
- result <- runParser p
- case result of
- Just a -> runParser (f a)
- Nothing -> do put saved -- 状態を復歸
- return Nothing
- return = Parser . return . Just
- fail _ = Parser $ return Nothing
-
-
-parse :: Parser a -> ByteString -> Maybe (a, ByteString)
-parse p input = case runState (runParser p) input of
- (Just a , input') -> Just (a, input')
- (Nothing, _ ) -> Nothing
-
-
-anyChar :: Parser Char
-anyChar = Parser $ do input <- get
- if B.null input then
- return Nothing
- else
- do let c = B.head input
- put (B.tail input)
- return (Just c)
-
-
-satisfy :: (Char -> Bool) -> Parser Char
-satisfy f = do c <- anyChar
- unless (f c) (fail "")
- return c
-
-
-char :: Char -> Parser Char
-char c = satisfy (== c)
-
-
-string :: String -> Parser String
-string str = do mapM_ char str
- return str
-
-
-infixr 0 <|>
-
-(<|>) :: Parser a -> Parser a -> Parser a
-f <|> g = Parser $ do saved <- get -- 状態を保存
- result <- runParser f
- case result of
- Just a -> return (Just a)
- Nothing -> do put saved -- 状態を復歸
- runParser g
-
-
-oneOf :: [Char] -> Parser Char
-oneOf = foldl (<|>) (fail "") . map char
-
-
-notFollowedBy :: Parser a -> Parser ()
-notFollowedBy p = p >>= fail "" <|> return ()
-
-
-digit :: Parser Char
-digit = oneOf "0123456789"
-
-
-many :: Parser a -> Parser [a]
-many p = do x <- p
- xs <- many p
- return (x:xs)
- <|>
- return []
-
-
-many1 :: Parser a -> Parser [a]
-many1 p = do ret <- many p
- case ret of
- [] -> fail ""
- xs -> return xs
-
-
-manyTill :: Parser a -> Parser end -> Parser [a]
-manyTill p end = many $ do x <- p
- end
- return x
-
-
-many1Till :: Parser a -> Parser end -> Parser [a]
-many1Till p end = many1 $ do x <- p
- end
- return x
-
-
-option :: a -> Parser a -> Parser a
-option def p = p <|> return def
-
-
-sp :: Parser Char
-sp = char ' '
-
-
-ht :: Parser Char
-ht = char '\t'
-
-
-crlf :: Parser String
-crlf = string "\x0d\x0a"
+import Blaze.ByteString.Builder (Builder, Write)
+import qualified Blaze.ByteString.Builder as BB
+import qualified Blaze.ByteString.Builder.Internal as BI
+import Control.Applicative
+import Control.Applicative.Unicode hiding ((∅))
+import Control.Monad.Unicode
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LS
+import Data.Monoid
+import Data.Monoid.Unicode
+import Data.Word
+import Prelude.Unicode
+
+-- |@'atMost' n v@ is like @'P.many' v@ but accumulates @v@ at most
+-- @n@ times.
+atMost ∷ Alternative f ⇒ Int → f a → f [a]
+{-# INLINE atMost #-}
+atMost 0 _ = pure []
+atMost n v = ( (:) <$> v ⊛ atMost (n-1) v )
+ <|>
+ pure []
+
+data OctetAccumState
+ = OctetAccumState {
+ casChunks ∷ !Builder
+ , casLastChunk ∷ !Write
+ }
+
+instance Monoid OctetAccumState where
+ {-# INLINE mempty #-}
+ mempty
+ = OctetAccumState {
+ casChunks = (∅)
+ , casLastChunk = (∅)
+ }
+ {-# INLINEABLE mappend #-}
+ mappend !a !b
+ = b {
+ casChunks = casChunks a ⊕ lastChunk a ⊕ casChunks b
+ }
+
+lastChunk ∷ OctetAccumState → Builder
+{-# INLINEABLE lastChunk #-}
+lastChunk !s = case toChunk s of
+ c → BB.insertByteString c
+ where
+ toChunk ∷ OctetAccumState → BS.ByteString
+ {-# INLINE toChunk #-}
+ toChunk = BB.toByteString ∘ BB.fromWrite ∘ casLastChunk
+
+snoc ∷ OctetAccumState → Word8 → OctetAccumState
+{-# INLINEABLE snoc #-}
+snoc !s !o
+ | BI.getBound (casLastChunk s) ≥ BI.defaultBufferSize
+ = s {
+ casChunks = casChunks s ⊕ lastChunk s
+ , casLastChunk = BB.writeWord8 o
+ }
+ | otherwise
+ = s {
+ casLastChunk = casLastChunk s ⊕ BB.writeWord8 o
+ }
+
+finish ∷ OctetAccumState → LS.ByteString
+{-# INLINEABLE finish #-}
+finish = BB.toLazyByteString ∘ toChunks
+ where
+ toChunks ∷ OctetAccumState → Builder
+ {-# INLINE toChunks #-}
+ toChunks !s = casChunks s ⊕ lastChunk s
+
+-- |@'manyOctetsTill' p end@ takes as many octets untill @p@ succeeds.
+manyOctetsTill ∷ ∀m b. (Monad m, Alternative m)
+ ⇒ m Word8
+ → m b
+ → m LS.ByteString
+{-# INLINEABLE manyOctetsTill #-}
+manyOctetsTill p end = scan (∅)
+ where
+ scan ∷ OctetAccumState → m LS.ByteString
+ {-# INLINE scan #-}
+ scan !s
+ = (end *> pure (finish s))
+ <|>
+ (scan =≪ (snoc s <$> p))