Code cleanup

[Lucu.git] / Network / HTTP / Lucu / Parser.hs

diff --git a/Network/HTTP/Lucu/Parser.hs b/Network/HTTP/Lucu/Parser.hs
index 3fa4c150e669dd088112efaf4f7f457fb36add83..660f550a9353cc687a56ae0e6e422ecc41a7e3f1 100644 (file)
--- a/Network/HTTP/Lucu/Parser.hs
+++ b/Network/HTTP/Lucu/Parser.hs
@@ -1,139 +1,57 @@
+{-# LANGUAGE
+    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
+    , finishOff
+    , skipManyTill
+    , skipWhile1
+    , skipSpace1
+    , isAlphaNum
     )
     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 Control.Applicative
+import Control.Applicative.Unicode
+import Control.Monad.Unicode
+import Data.Attoparsec.Char8
+import Prelude.Unicode
+
+-- |@'atMost' n v@ is like @'P.many' v@ but accumulates @v@ at most
+-- @n@ times.
+atMost ∷ Alternative f ⇒ Int → f α → f [α]
+{-# INLINEABLE atMost #-}
+atMost 0 _ = pure []
+atMost n v = ( (:) <$> v ⊛ atMost (n-1) v )
+             <|>
+             pure []
+
+-- |@'finishOff' p@ is equivalent to @p '>>=' \\a -> 'endOfInput' '>>'
+-- 'return' a@.
+finishOff ∷ Parser α → Parser α
+{-# INLINE finishOff #-}
+finishOff = ((endOfInput *>) ∘ return =≪)
+
+-- |Similar to 'manyTill' but discards the result.
+skipManyTill ∷ Alternative f ⇒ f α → f β → f ()
+{-# INLINEABLE skipManyTill #-}
+skipManyTill p end = go
+    where
+      go = (end *> pure ()) <|> (p *> go)
+
+-- |Similar to 'skipWhile' but consumes at least one character.
+skipWhile1 ∷ (Char → Bool) → Parser ()
+{-# INLINE skipWhile1 #-}
+skipWhile1 p = takeWhile1 p *> pure ()
+
+-- |Similar to 'skipSpace' but consumes at least one whitespace.
+skipSpace1 ∷ Parser ()
+{-# INLINE skipSpace1 #-}
+skipSpace1 = skipMany1 space
+
+-- |@'isAlphaNum' c@ returns 'True' iff @'isDigit' c ||
+-- 'isAlpha_ascii' c@.
+isAlphaNum ∷ Char → Bool
+{-# INLINE isAlphaNum #-}
+isAlphaNum c = isDigit c ∨ isAlpha_ascii c