, hexDigit
, notFollowedBy
, many
+ , manyChar
, many1
, count
, option
)
where
-import Control.Monad.State.Strict
+import Control.Monad.State.Strict hiding (state)
import qualified Data.ByteString.Lazy as Lazy (ByteString)
import qualified Data.ByteString.Lazy.Char8 as B hiding (ByteString)
+import qualified Data.Foldable as Fold
+import Data.Int
+import qualified Data.Sequence as Seq
+import Data.Sequence (Seq, (|>))
-- |@'Parser' a@ is obviously a parser which parses and returns @a@.
newtype Parser a = Parser {
return IllegalInput
ReachedEOF -> do put saved -- 状態を復歸
return ReachedEOF
- return x = x `seq` Parser $! return $! Success x
- fail _ = Parser $! return $! IllegalInput
+ return !x = Parser $! return $! Success x
+ fail _ = Parser $! return $! IllegalInput
+
+instance Functor Parser where
+ fmap f p = p >>= return . f
-- |@'failP'@ is just a synonym for @'Prelude.fail'
-- 'Prelude.undefined'@.
-- |@'parse' p bstr@ parses @bstr@ with @p@ and returns @(# result,
-- remaining #)@.
parse :: Parser a -> Lazy.ByteString -> (# ParserResult a, Lazy.ByteString #)
-parse p input -- input は lazy である必要有り。
- = p `seq`
- let (result, state') = runState (runParser p) (PST input True)
+parse !p input -- input は lazy である必要有り。
+ = let (!result, state') = runState (runParser p) (PST input True)
in
- result `seq` (# result, pstInput state' #) -- pstInput state' も lazy である必要有り。
+ (# result, pstInput state' #) -- pstInput state' も lazy である必要有り。
-- |@'parseStr' p str@ packs @str@ and parses it.
parseStr :: Parser a -> String -> (# ParserResult a, Lazy.ByteString #)
-parseStr p input
- = p `seq` -- input は lazy である必要有り。
- parse p (B.pack input)
+parseStr !p input -- input は lazy である必要有り。
+ = parse p (B.pack input)
anyChar :: Parser Char
-- |@'allowEOF' p@ makes @p@ treat reaching EOF a normal failure.
allowEOF :: Parser a -> Parser a
-allowEOF f = f `seq`
- Parser $! do saved@(PST _ isEOFFatal) <- get
- put $! saved { pstIsEOFFatal = False }
+allowEOF !f
+ = Parser $! do saved@(PST _ isEOFFatal) <- get
+ put $! saved { pstIsEOFFatal = False }
- result <- runParser f
+ result <- runParser f
- state <- get
- put $! state { pstIsEOFFatal = isEOFFatal }
+ state <- get
+ put $! state { pstIsEOFFatal = isEOFFatal }
- return result
+ return result
satisfy :: (Char -> Bool) -> Parser Char
-satisfy f = f `seq`
- do c <- anyChar
- if f $! c then
- return c
- else
- failP
+satisfy !f
+ = do c <- anyChar
+ if f c then
+ return c
+ else
+ failP
char :: Char -> Parser Char
-char c = c `seq` satisfy (== c)
+char !c = satisfy (== c)
string :: String -> Parser String
-string str = str `seq`
- do mapM_ char str
- return str
+string !str
+ = let bs = B.pack str
+ len = B.length bs
+ in
+ Parser $!
+ do st <- get
+ let (bs', rest) = B.splitAt len $ pstInput st
+ st' = st { pstInput = rest }
+ if B.length bs' < len then
+ return ReachedEOF
+ else
+ if bs == bs' then
+ do put st'
+ return $ Success str
+ else
+ return IllegalInput
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 <- get -- 状態を保存
+(!f) <|> (!g)
+ = Parser $! do saved <- get -- 状態を保存
result <- runParser f
case result of
Success a -> return $! Success a
notFollowedBy :: Parser a -> Parser ()
-notFollowedBy p
- = p `seq`
- Parser $! do saved <- get -- 状態を保存
+notFollowedBy !p
+ = Parser $! do saved <- get -- 状態を保存
result <- runParser p
case result of
Success _ -> do put saved -- 状態を復歸
failP
-many :: Parser a -> Parser [a]
-many !p = Parser $! many' p []
-
--- This implementation is rather ugly but we need to make it
--- tail-recursive to avoid stack overflow.
-many' :: Parser a -> [a] -> State ParserState (ParserResult [a])
-many' !p !soFar
- = do saved <- get
- result <- runParser p
- case result of
- Success a -> many' p (a:soFar)
- IllegalInput -> do put saved
- return $! Success $ reverse soFar
- ReachedEOF -> if pstIsEOFFatal saved then
- do put saved
- return ReachedEOF
- else
- do put saved
- return $! Success $ reverse soFar
+many :: forall a. Parser a -> Parser [a]
+many !p = Parser $!
+ do state <- get
+ let (# result, state' #) = many' state Seq.empty
+ put state'
+ return result
+ where
+ many' :: ParserState -> Seq a -> (# ParserResult [a], ParserState #)
+ many' !st !soFar
+ = case runState (runParser p) st of
+ (Success a, st') -> many' st' (soFar |> a)
+ (IllegalInput, _) -> (# Success (Fold.toList soFar), st #)
+ (ReachedEOF , _) -> if pstIsEOFFatal st then
+ (# ReachedEOF, st #)
+ else
+ (# Success (Fold.toList soFar), st #)
+
+manyChar :: Parser Char -> Parser Lazy.ByteString
+manyChar !p = Parser $!
+ do state <- get
+ case scan' state 0 of
+ Success len
+ -> do let (bs, rest) = B.splitAt len (pstInput state)
+ state' = state { pstInput = rest }
+ put state'
+ return $ Success bs
+ ReachedEOF
+ -> if pstIsEOFFatal state then
+ return ReachedEOF
+ else
+ error "internal error"
+ _ -> error "internal error"
+ where
+ scan' :: ParserState -> Int64 -> ParserResult Int64
+ scan' !st !soFar
+ = case runState (runParser p) st of
+ (Success _ , st') -> scan' st' (soFar + 1)
+ (IllegalInput, _ ) -> Success soFar
+ (ReachedEOF , _ ) -> if pstIsEOFFatal st then
+ ReachedEOF
+ else
+ Success soFar
many1 :: Parser a -> Parser [a]
count :: Int -> Parser a -> Parser [a]
-count !n !p = Parser $! count' n p []
+count !n !p = Parser $! count' n p Seq.empty
-- This implementation is rather ugly but we need to make it
-- tail-recursive to avoid stack overflow.
-count' :: Int -> Parser a -> [a] -> State ParserState (ParserResult [a])
-count' 0 _ !soFar = return $! Success $ reverse soFar
+count' :: Int -> Parser a -> Seq a -> State ParserState (ParserResult [a])
+count' 0 _ !soFar = return $! Success $! Fold.toList soFar
count' !n !p !soFar = do saved <- get
result <- runParser p
case result of
- Success a -> count' (n-1) p (a:soFar)
+ Success a -> count' (n-1) p (soFar |> a)
IllegalInput -> do put saved
return IllegalInput
ReachedEOF -> do put saved
-- def may be a _|_
option :: a -> Parser a -> Parser a
-option def p = p `seq`
- p <|> return def
+option def !p = p <|> return def
sepBy :: Parser a -> Parser sep -> Parser [a]
-sepBy p sep = p `seq` sep `seq`
- sepBy1 p sep <|> return []
+sepBy !p !sep = 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)
+sepBy1 !p !sep
+ = do x <- p
+ xs <- many $! sep >> p
+ return (x:xs)
sp :: Parser Char
projects / Lucu.git / blobdiff