X-Git-Url: http://git.cielonegro.org/gitweb.cgi?p=Lucu.git;a=blobdiff_plain;f=Network%2FHTTP%2FLucu%2FParser.hs;h=660f550a9353cc687a56ae0e6e422ecc41a7e3f1;hp=0033eb482e88b80d111b2aededf9705c5cbb8ac5;hb=19043d7;hpb=858129cb755aa09da2b7bd758efb8519f2c89103 diff --git a/Network/HTTP/Lucu/Parser.hs b/Network/HTTP/Lucu/Parser.hs index 0033eb4..660f550 100644 --- a/Network/HTTP/Lucu/Parser.hs +++ b/Network/HTTP/Lucu/Parser.hs @@ -1,266 +1,57 @@ --- |Yet another parser combinator. This is mostly a subset of Parsec --- but there are some differences: --- --- * This parser works on ByteString instead of String. --- --- * Backtracking is the only possible behavior so there is no \"try\" --- action. --- --- * On success, the remaining string is returned as well as the --- parser result. --- --- * You can choose whether to treat reaching EOF (trying to eat one --- more letter at the end of string) a fatal error or to treat it a --- normal failure. If a fatal error occurs, the entire parsing --- process immediately fails without trying any backtracks. The --- default behavior is to treat EOF fatal. --- --- In general, you don't have to use this module directly. +{-# LANGUAGE + UnicodeSyntax + #-} +-- |This is an auxiliary parser utilities. You usually don't have to +-- use this module directly. module Network.HTTP.Lucu.Parser - ( Parser - , ParserResult(..) - - , parse - , parseStr - - , anyChar - , eof - , allowEOF - , satisfy - , char - , string - , (<|>) - , oneOf - , digit - , hexDigit - , notFollowedBy - , many - , many1 - , manyTill - , many1Till - , count - , option - , sepBy - , sepBy1 - - , sp - , ht - , crlf + ( 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) - --- |@Parser a@ is obviously a parser which parses and returns @a@. -newtype Parser a = Parser { - runParser :: State ParserState (ParserResult a) - } - -type ParserState = (ByteString, IsEOFFatal) - -type IsEOFFatal = Bool - -data ParserResult a = Success !a - | IllegalInput -- 受理出來ない入力があった - | ReachedEOF -- 限界を越えて讀まうとした - deriving (Eq, Show) - - --- (>>=) :: Parser a -> (a -> Parser b) -> Parser b -instance Monad Parser where - p >>= f = Parser $! do saved@(_, isEOFFatal) <- get -- 失敗した時の爲に状態を保存 - result <- runParser p - case result of - Success a -> a `seq` runParser (f a) - IllegalInput -> do put saved -- 状態を復歸 - return IllegalInput - ReachedEOF -> do unless isEOFFatal - $ put saved -- 状態を復歸 - return ReachedEOF - return x = x `seq` Parser $! return $! Success x - fail _ = Parser $! return $! IllegalInput - --- |@'parse' p bstr@ parses @bstr@ with @p@ and returns @(result, --- remaining)@. -parse :: Parser a -> ByteString -> (ParserResult a, ByteString) -parse p input -- input は lazy である必要有り。 - = p `seq` - let (result, (input', _)) = runState (runParser p) (input, True) - in - result `seq` (result, input') -- input' も lazy である必要有り。 - --- |@'parseStr' p str@ packs @str@ and parses it. -parseStr :: Parser a -> String -> (ParserResult a, ByteString) -parseStr p input - = p `seq` -- input は lazy である必要有り。 - parse p $! B.pack input - - -anyChar :: Parser Char -anyChar = Parser $! - do (input, isEOFFatal) <- get - if B.null input then - return ReachedEOF - else - do let c = B.head input - put (B.tail input, isEOFFatal) - return (Success c) - - -eof :: Parser () -eof = Parser $! - do (input, _) <- get - if B.null input then - return $ Success () - else - return IllegalInput - --- |@'allowEOF' p@ makes @p@ treat reaching EOF a normal failure. -allowEOF :: Parser a -> Parser a -allowEOF f = f `seq` - Parser $! do (input, isEOFFatal) <- get - put (input, False) - - result <- runParser f - - (input', _) <- get - put (input', isEOFFatal) - - return result - - -satisfy :: (Char -> Bool) -> Parser Char -satisfy f = f `seq` - do c <- anyChar - unless (f c) (fail "") - return c - - -char :: Char -> Parser Char -char c = c `seq` satisfy (== c) - - -string :: String -> Parser String -string str = str `seq` - do mapM_ char str - return str - - -infixr 0 <|> - --- |This is the backtracking alternation. There is no non-backtracking --- equivalent. -(<|>) :: Parser a -> Parser a -> Parser a -f <|> g - = f `seq` g `seq` - Parser $! do saved@(_, isEOFFatal) <- get -- 状態を保存 - result <- runParser f - case result of - Success a -> return $ Success a - IllegalInput -> do put saved -- 状態を復歸 - runParser g - ReachedEOF -> if isEOFFatal then - return ReachedEOF - else - do put saved - runParser g - - -oneOf :: [Char] -> Parser Char -oneOf = foldl (<|>) (fail "") . map char - - -notFollowedBy :: Parser a -> Parser () -notFollowedBy p = p `seq` - p >>= fail "" <|> return () - - -digit :: Parser Char -digit = do c <- anyChar - if c >= '0' && c <= '9' then - return c - else - fail "" - - -hexDigit :: Parser Char -hexDigit = do c <- anyChar - if (c >= '0' && c <= '9') || - (c >= 'a' && c <= 'f') || - (c >= 'A' && c <= 'F') then - return c - else - fail "" - - -many :: Parser a -> Parser [a] -many p = p `seq` - do x <- p - xs <- many p - return (x:xs) - <|> - return [] - - -many1 :: Parser a -> Parser [a] -many1 p = p `seq` - do ret <- many p - case ret of - [] -> fail "" - xs -> return xs - - -manyTill :: Parser a -> Parser end -> Parser [a] -manyTill p end - = p `seq` end `seq` - many $! do x <- p - end - return x - - -many1Till :: Parser a -> Parser end -> Parser [a] -many1Till p end - = p `seq` end `seq` - many1 $! do x <- p - end - return x - - -count :: Int -> Parser a -> Parser [a] -count 0 _ = return [] -count n p = n `seq` p `seq` - do x <- p - xs <- count (n-1) p - return (x:xs) - --- def may be a _|_ -option :: a -> Parser a -> Parser a -option def p = p `seq` - p <|> return def - - -sepBy :: Parser a -> Parser sep -> Parser [a] -sepBy p sep = p `seq` sep `seq` - sepBy1 p sep <|> return [] - - -sepBy1 :: Parser a -> Parser sep -> Parser [a] -sepBy1 p sep = p `seq` sep `seq` - do x <- p - xs <- many $! sep >> p - return (x:xs) - - -sp :: Parser Char -sp = char ' ' - - -ht :: Parser Char -ht = char '\t' - - -crlf :: Parser String -crlf = string "\x0d\x0a" +import Control.Applicative +import Control.Applicative.Unicode +import Control.Monad.Unicode +import Data.Attoparsec.Char8 +import Prelude.Unicode + +-- |@'atMost' n v@ is like @'P.many' v@ but accumulates @v@ at most +-- @n@ times. +atMost ∷ Alternative f ⇒ Int → f α → f [α] +{-# INLINEABLE atMost #-} +atMost 0 _ = pure [] +atMost n v = ( (:) <$> 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