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Diffstat (limited to 'haddock-library/vendor/attoparsec-0.10.4.0/Data/Attoparsec/Internal')
-rw-r--r-- | haddock-library/vendor/attoparsec-0.10.4.0/Data/Attoparsec/Internal/Types.hs | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/haddock-library/vendor/attoparsec-0.10.4.0/Data/Attoparsec/Internal/Types.hs b/haddock-library/vendor/attoparsec-0.10.4.0/Data/Attoparsec/Internal/Types.hs new file mode 100644 index 00000000..e47e5c9e --- /dev/null +++ b/haddock-library/vendor/attoparsec-0.10.4.0/Data/Attoparsec/Internal/Types.hs @@ -0,0 +1,227 @@ +{-# LANGUAGE BangPatterns, CPP, GeneralizedNewtypeDeriving, OverloadedStrings, + Rank2Types, RecordWildCards #-} +-- | +-- Module : Data.Attoparsec.Internal.Types +-- Copyright : Bryan O'Sullivan 2007-2011 +-- License : BSD3 +-- +-- Maintainer : bos@serpentine.com +-- Stability : experimental +-- Portability : unknown +-- +-- Simple, efficient parser combinators, loosely based on the Parsec +-- library. + +module Data.Attoparsec.Internal.Types + ( + Parser(..) + , Failure + , Success + , IResult(..) + , Input(..) + , Added(..) + , More(..) + , addS + , (<>) + ) where + +import Control.Applicative (Alternative(..), Applicative(..), (<$>)) +import Control.DeepSeq (NFData(rnf)) +import Control.Monad (MonadPlus(..)) +import Data.Monoid (Monoid(..)) +import Prelude hiding (getChar, take, takeWhile) + +-- | The result of a parse. This is parameterised over the type @t@ +-- of string that was processed. +-- +-- This type is an instance of 'Functor', where 'fmap' transforms the +-- value in a 'Done' result. +data IResult t r = Fail t [String] String + -- ^ The parse failed. The 't' parameter is the + -- input that had not yet been consumed when the + -- failure occurred. The @[@'String'@]@ is a list of + -- contexts in which the error occurred. The + -- 'String' is the message describing the error, if + -- any. + | Partial (t -> IResult t r) + -- ^ Supply this continuation with more input so that + -- the parser can resume. To indicate that no more + -- input is available, use an empty string. + | Done t r + -- ^ The parse succeeded. The 't' parameter is the + -- input that had not yet been consumed (if any) when + -- the parse succeeded. + +instance (Show t, Show r) => Show (IResult t r) where + show (Fail t stk msg) = + "Fail " ++ show t ++ " " ++ show stk ++ " " ++ show msg + show (Partial _) = "Partial _" + show (Done t r) = "Done " ++ show t ++ " " ++ show r + +instance (NFData t, NFData r) => NFData (IResult t r) where + rnf (Fail t stk msg) = rnf t `seq` rnf stk `seq` rnf msg + rnf (Partial _) = () + rnf (Done t r) = rnf t `seq` rnf r + {-# INLINE rnf #-} + +fmapR :: (a -> b) -> IResult t a -> IResult t b +fmapR _ (Fail t stk msg) = Fail t stk msg +fmapR f (Partial k) = Partial (fmapR f . k) +fmapR f (Done t r) = Done t (f r) + +instance Functor (IResult t) where + fmap = fmapR + {-# INLINE fmap #-} + +newtype Input t = I {unI :: t} deriving (Monoid) +newtype Added t = A {unA :: t} deriving (Monoid) + +-- | The core parser type. This is parameterised over the type @t@ of +-- string being processed. +-- +-- This type is an instance of the following classes: +-- +-- * 'Monad', where 'fail' throws an exception (i.e. fails) with an +-- error message. +-- +-- * 'Functor' and 'Applicative', which follow the usual definitions. +-- +-- * 'MonadPlus', where 'mzero' fails (with no error message) and +-- 'mplus' executes the right-hand parser if the left-hand one +-- fails. When the parser on the right executes, the input is reset +-- to the same state as the parser on the left started with. (In +-- other words, Attoparsec is a backtracking parser that supports +-- arbitrary lookahead.) +-- +-- * 'Alternative', which follows 'MonadPlus'. +newtype Parser t a = Parser { + runParser :: forall r. Input t -> Added t -> More + -> Failure t r + -> Success t a r + -> IResult t r + } + +type Failure t r = Input t -> Added t -> More -> [String] -> String + -> IResult t r +type Success t a r = Input t -> Added t -> More -> a -> IResult t r + +-- | Have we read all available input? +data More = Complete | Incomplete + deriving (Eq, Show) + +instance Monoid More where + mappend c@Complete _ = c + mappend _ m = m + mempty = Incomplete + +addS :: (Monoid t) => + Input t -> Added t -> More + -> Input t -> Added t -> More + -> (Input t -> Added t -> More -> r) -> r +addS i0 a0 m0 _i1 a1 m1 f = + let !i = i0 <> I (unA a1) + a = a0 <> a1 + !m = m0 <> m1 + in f i a m +{-# INLINE addS #-} + +bindP :: Parser t a -> (a -> Parser t b) -> Parser t b +bindP m g = + Parser $ \i0 a0 m0 kf ks -> runParser m i0 a0 m0 kf $ + \i1 a1 m1 a -> runParser (g a) i1 a1 m1 kf ks +{-# INLINE bindP #-} + +returnP :: a -> Parser t a +returnP a = Parser (\i0 a0 m0 _kf ks -> ks i0 a0 m0 a) +{-# INLINE returnP #-} + +instance Monad (Parser t) where + return = returnP + (>>=) = bindP + fail = failDesc + +noAdds :: (Monoid t) => + Input t -> Added t -> More + -> (Input t -> Added t -> More -> r) -> r +noAdds i0 _a0 m0 f = f i0 mempty m0 +{-# INLINE noAdds #-} + +plus :: (Monoid t) => Parser t a -> Parser t a -> Parser t a +plus a b = Parser $ \i0 a0 m0 kf ks -> + let kf' i1 a1 m1 _ _ = addS i0 a0 m0 i1 a1 m1 $ + \ i2 a2 m2 -> runParser b i2 a2 m2 kf ks + ks' i1 a1 m1 = ks i1 (a0 <> a1) m1 + in noAdds i0 a0 m0 $ \i2 a2 m2 -> runParser a i2 a2 m2 kf' ks' +{-# INLINE plus #-} + +instance (Monoid t) => MonadPlus (Parser t) where + mzero = failDesc "mzero" + {-# INLINE mzero #-} + mplus = plus + +fmapP :: (a -> b) -> Parser t a -> Parser t b +fmapP p m = Parser $ \i0 a0 m0 f k -> + runParser m i0 a0 m0 f $ \i1 a1 s1 a -> k i1 a1 s1 (p a) +{-# INLINE fmapP #-} + +instance Functor (Parser t) where + fmap = fmapP + {-# INLINE fmap #-} + +apP :: Parser t (a -> b) -> Parser t a -> Parser t b +apP d e = do + b <- d + a <- e + return (b a) +{-# INLINE apP #-} + +instance Applicative (Parser t) where + pure = returnP + {-# INLINE pure #-} + (<*>) = apP + {-# INLINE (<*>) #-} + +#if MIN_VERSION_base(4,2,0) + -- These definitions are equal to the defaults, but this + -- way the optimizer doesn't have to work so hard to figure + -- that out. + (*>) = (>>) + {-# INLINE (*>) #-} + x <* y = x >>= \a -> y >> return a + {-# INLINE (<*) #-} +#endif + +instance (Monoid t) => Monoid (Parser t a) where + mempty = failDesc "mempty" + {-# INLINE mempty #-} + mappend = plus + {-# INLINE mappend #-} + +instance (Monoid t) => Alternative (Parser t) where + empty = failDesc "empty" + {-# INLINE empty #-} + + (<|>) = plus + {-# INLINE (<|>) #-} + +#if MIN_VERSION_base(4,2,0) + many v = many_v + where many_v = some_v <|> pure [] + some_v = (:) <$> v <*> many_v + {-# INLINE many #-} + + some v = some_v + where + many_v = some_v <|> pure [] + some_v = (:) <$> v <*> many_v + {-# INLINE some #-} +#endif + +failDesc :: String -> Parser t a +failDesc err = Parser (\i0 a0 m0 kf _ks -> kf i0 a0 m0 [] msg) + where msg = "Failed reading: " ++ err +{-# INLINE failDesc #-} + +(<>) :: (Monoid m) => m -> m -> m +(<>) = mappend +{-# INLINE (<>) #-} |