--- |Yet another parser combinator. This is mostly a subset of
--- "Text.ParserCombinators.Parsec" but there are some differences:
---
--- * This parser works on 'Data.ByteString.Base.LazyByteString'
--- instead of 'Prelude.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(..)
-
- , failP
-
- , parse
- , parseStr
-
- , anyChar
- , eof
- , allowEOF
- , satisfy
- , char
- , string
- , (<|>)
- , choice
- , oneOf
- , digit
- , hexDigit
- , notFollowedBy
- , many
- , many1
- , count
- , option
- , sepBy
- , sepBy1
-
- , sp
- , ht
- , crlf
+ ( atMost
+ , finishOff
+ , skipManyTill
+ , skipWhile1
+ , skipSpace1
+ , isAlphaNum
)
where
-
-import Control.Monad.State.Strict
-import qualified Data.ByteString.Lazy as Lazy (ByteString)
-import qualified Data.ByteString.Lazy.Char8 as B hiding (ByteString)
-
--- |@'Parser' a@ is obviously a parser which parses and returns @a@.
-newtype Parser a = Parser {
- runParser :: State ParserState (ParserResult a)
- }
-
-
-data ParserState
- = PST {
- pstInput :: Lazy.ByteString
- , pstIsEOFFatal :: !Bool
- }
- deriving (Eq, Show)
-
-
-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 <- get -- 失敗した時の爲に状態を保存
- result <- runParser p
- case result of
- Success a -> runParser (f a)
- IllegalInput -> do put saved -- 状態を復歸
- 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
-
--- |@'failP'@ is just a synonym for @'Prelude.fail'
--- 'Prelude.undefined'@.
-failP :: Parser a
-failP = fail 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)
- in
- result `seq` (# 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)
-
-
-anyChar :: Parser Char
-anyChar = Parser $!
- do state@(PST input _) <- get
- if B.null input then
- return ReachedEOF
- else
- do put $! state { pstInput = B.tail input }
- return (Success $! B.head input)
-
-
-eof :: Parser ()
-eof = Parser $!
- do PST 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 saved@(PST _ isEOFFatal) <- get
- put $! saved { pstIsEOFFatal = False }
-
- result <- runParser f
-
- state <- get
- put $! state { pstIsEOFFatal = isEOFFatal }
-
- return result
-
-
-satisfy :: (Char -> Bool) -> Parser Char
-satisfy f = f `seq`
- do c <- anyChar
- if f $! c then
- return c
- else
- failP
-
-
-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 <- 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 pstIsEOFFatal saved then
- return ReachedEOF
- else
- do put saved
- runParser g
-
-
-choice :: [Parser a] -> Parser a
-choice = foldl (<|>) failP
-
-
-oneOf :: [Char] -> Parser Char
-oneOf = foldl (<|>) failP . map char
-
-
-notFollowedBy :: Parser a -> Parser ()
-notFollowedBy p
- = p `seq`
- Parser $! do saved <- get -- 状態を保存
- result <- runParser p
- case result of
- Success _ -> do put saved -- 状態を復歸
- return IllegalInput
- IllegalInput -> do put saved -- 状態を復歸
- return $! Success ()
- ReachedEOF -> do put saved -- 状態を復歸
- return $! Success ()
-
-
-digit :: Parser Char
-digit = do c <- anyChar
- if c >= '0' && c <= '9' then
- return c
- else
- failP
-
-
-hexDigit :: Parser Char
-hexDigit = do c <- anyChar
- if (c >= '0' && c <= '9') ||
- (c >= 'a' && c <= 'f') ||
- (c >= 'A' && c <= 'F') then
- return c
- else
- failP
-
-
-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 x <- p
- xs <- many p
- return (x:xs)
-
-
-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
projects / Lucu.git / blobdiff