    {-# LANGUAGE BangPatterns               #-}
    {-# LANGUAGE DeriveAnyClass             #-}
    {-# LANGUAGE DeriveDataTypeable         #-}
    {-# LANGUAGE DeriveGeneric              #-}
    {-# LANGUAGE GeneralizedNewtypeDeriving #-}
    {-# LANGUAGE CPP                        #-}
    -- | DOM parser and API for XML.
    --   Slightly slower DOM parsing,
    --   but add missing close tags.
    module Xeno.DOM.Robust
      ( parse
      , Node
      , Content(..)
      , name
      , attributes
      , contents
      , children
      ) where

    import           Control.Monad.ST
    import           Control.Spork
    #if MIN_VERSION_bytestring(0,11,0)
    import           Data.ByteString.Internal as BS (ByteString(..), plusForeignPtr)
    #else
    import           Data.ByteString.Internal(ByteString(..))
    #endif
    import           Data.STRef
    import qualified Data.Vector.Unboxed         as UV
    import qualified Data.Vector.Unboxed.Mutable as UMV
    import           Data.Mutable(asURef, newRef, readRef, writeRef)
    #if MIN_VERSION_bytestring(0,11,0)
    import           Foreign.Ptr (minusPtr)
    import           Foreign.ForeignPtr (ForeignPtr, withForeignPtr)
    import           System.IO.Unsafe (unsafeDupablePerformIO)
    #endif
    import           Xeno.SAX
    import           Xeno.Types
    import           Xeno.DOM.Internal(Node(..), Content(..), name, attributes, contents, children)

    -- | Parse a complete Nodes document.
    parse :: ByteString -> Either XenoException Node
    parse :: ByteString -> Either XenoException Node
    parse ByteString
    inp =
      case Vector Int -> Either XenoException (Vector Int)
    forall e a. Exception e => a -> Either e a
    spork Vector Int
    node of
        Left XenoException
    e -> XenoException -> Either XenoException Node
    forall a b. a -> Either a b
    Left XenoException
    e
        Right Vector Int
    r ->
          case Vector Int -> Maybe Node
    findRootNode Vector Int
    r of
            Just Node
    n -> Node -> Either XenoException Node
    forall a b. b -> Either a b
    Right Node
    n
            Maybe Node
    Nothing -> XenoException -> Either XenoException Node
    forall a b. a -> Either a b
    Left XenoException
    XenoExpectRootNode
      where
        findRootNode :: Vector Int -> Maybe Node
    findRootNode Vector Int
    r = Int -> Maybe Node
    go Int
    0
          where
            go :: Int -> Maybe Node
    go Int
    n = case Vector Int
    r Vector Int -> Int -> Maybe Int
    forall a. Unbox a => Vector a -> Int -> Maybe a
    UV.!? Int
    n of
              Just Int
    0x0 -> Node -> Maybe Node
    forall a. a -> Maybe a
    Just (ByteString -> Int -> Vector Int -> Node
    Node ByteString
    str Int
    n Vector Int
    r)
              -- skipping text assuming that it contains only white space
              -- characters
              Just Int
    0x1 -> Int -> Maybe Node
    go (Int
    nInt -> Int -> Int
    forall a. Num a => a -> a -> a
    +Int
    3)
              Maybe Int
    _ -> Maybe Node
    forall a. Maybe a
    Nothing
    #if MIN_VERSION_bytestring(0,11,0)
        BS ForeignPtr Word8
    offset0 Int
    _ = ByteString
    str
    #else
        PS _ offset0 _ = str
    #endif
        str :: ByteString
    str = ByteString -> ByteString
    skipDoctype ByteString
    inp
        node :: Vector Int
    node =
          (forall s. ST s (Vector Int)) -> Vector Int
    forall a. (forall s. ST s a) -> a
    runST
            (do nil <- Int -> ST s (MVector (PrimState (ST s)) Int)
    forall (m :: * -> *) a.
    (PrimMonad m, Unbox a) =>
    Int -> m (MVector (PrimState m) a)
    UMV.new Int
    1000
                vecRef    <- newSTRef nil
                sizeRef   <- fmap asURef $ newRef 0
                parentRef <- fmap asURef $ newRef 0
                process Process {
    #if MIN_VERSION_bytestring(0,11,0)
                    openF = \(BS ForeignPtr Word8
    name_start Int
    name_len) -> do
    #else
                    openF = \(PS _ name_start name_len) -> do
    #endif
                     let tag :: Int
    tag = Int
    0x00
                         tag_end :: Int
    tag_end = -Int
    1
                     index <- URef s Int -> ST s (RefElement (URef s Int))
    forall c (m :: * -> *).
    (MutableRef c, PrimMonad m, PrimState m ~ MCState c) =>
    c -> m (RefElement c)
    forall (m :: * -> *).
    (PrimMonad m, PrimState m ~ MCState (URef s Int)) =>
    URef s Int -> m (RefElement (URef s Int))
    readRef URef s Int
    sizeRef
                     v' <-
                       do v <- readSTRef vecRef
                          if index + 5 < UMV.length v
                            then pure v
                            else do
                              v' <- UMV.grow v (UMV.length v)
                              writeSTRef vecRef v'
                              return v'
                     tag_parent <- readRef parentRef
                     do writeRef parentRef index
                        writeRef sizeRef (index + 5)
                        UMV.write v' index tag
                        UMV.write v' (index + 1) tag_parent
                        UMV.write v' (index + 2) (distance name_start offset0)
                        UMV.write v' (index + 3) name_len
                        UMV.write v' (index + 4) tag_end
    #if MIN_VERSION_bytestring(0,11,0)
                  , attrF = \(BS ForeignPtr Word8
    key_start Int
    key_len) (BS ForeignPtr Word8
    value_start Int
    value_len) -> do
    #else
                  , attrF = \(PS _ key_start key_len) (PS _ value_start value_len) -> do
    #endif
                     index <- URef s Int -> ST s (RefElement (URef s Int))
    forall c (m :: * -> *).
    (MutableRef c, PrimMonad m, PrimState m ~ MCState c) =>
    c -> m (RefElement c)
    forall (m :: * -> *).
    (PrimMonad m, PrimState m ~ MCState (URef s Int)) =>
    URef s Int -> m (RefElement (URef s Int))
    readRef URef s Int
    sizeRef
                     v' <-
                       do v <- readSTRef vecRef
                          if index + 5 < UMV.length v
                            then pure v
                            else do
                              v' <- UMV.grow v (UMV.length v)
                              writeSTRef vecRef v'
                              return v'
                     let tag = Int
    0x02
                     do writeRef sizeRef (index + 5)
                     do UMV.write v' index tag
                        UMV.write v' (index + 1) (distance key_start offset0)
                        UMV.write v' (index + 2) key_len
                        UMV.write v' (index + 3) (distance value_start offset0)
                        UMV.write v' (index + 4) value_len
                  , endOpenF = \ByteString
    _ -> () -> ST s ()
    forall a. a -> ST s a
    forall (m :: * -> *) a. Monad m => a -> m a
    return ()
    #if MIN_VERSION_bytestring(0,11,0)
                  , textF = \(BS ForeignPtr Word8
    text_start Int
    text_len) -> do
    #else
                  , textF = \(PS _ text_start text_len) -> do
    #endif
                     let tag :: Int
    tag = Int
    0x01
                     index <- URef s Int -> ST s (RefElement (URef s Int))
    forall c (m :: * -> *).
    (MutableRef c, PrimMonad m, PrimState m ~ MCState c) =>
    c -> m (RefElement c)
    forall (m :: * -> *).
    (PrimMonad m, PrimState m ~ MCState (URef s Int)) =>
    URef s Int -> m (RefElement (URef s Int))
    readRef URef s Int
    sizeRef
                     v' <-
                       do v <- readSTRef vecRef
                          if index + 3 < UMV.length v
                            then pure v
                            else do
                              v' <- UMV.grow v (UMV.length v)
                              writeSTRef vecRef v'
                              return v'
                     do writeRef sizeRef (index + 3)
                     do UMV.write v' index tag
                        UMV.write v' (index + 1) (distance text_start offset0)
                        UMV.write v' (index + 2) text_len
    #if MIN_VERSION_bytestring(0,11,0)
                  , closeF = \closeTag :: ByteString
    closeTag@(BS ForeignPtr Word8
    _ Int
    _) -> do
    #else
                  , closeF = \closeTag@(PS s _ _) -> do
    #endif
                     v <- STRef s (MVector s Int) -> ST s (MVector s Int)
    forall s a. STRef s a -> ST s a
    readSTRef STRef s (MVector s Int)
    vecRef
                     -- Set the tag_end slot of the parent.
                     index <- readRef sizeRef
                     untilM $ do
                       parent <- readRef parentRef
                       correctTag <- if parent == 0
                                        then return True -- no more tags to close!!!
                                        else do
                                          parent_name <- UMV.read v (parent + 2)
                                          parent_len  <- UMV.read v (parent + 3)
    #if MIN_VERSION_bytestring(0,11,0)
                                          let openTag  = ForeignPtr Word8 -> Int -> ByteString
    BS (ForeignPtr Word8 -> Int -> ForeignPtr Word8
    forall a b. ForeignPtr a -> Int -> ForeignPtr b
    BS.plusForeignPtr ForeignPtr Word8
    offset0 Int
    parent_name) Int
    parent_len
    #else
                                          let openTag  = PS s (parent_name+offset0) parent_len
    #endif
                                          return       $ openTag == closeTag
                       UMV.write                  v (parent + 4) index
                       -- Pop the stack and return to the parent element.
                       previousParent <- UMV.read v (parent + 1)
                       writeRef parentRef previousParent
                       return correctTag -- continue closing tags, until matching one is found
    #if MIN_VERSION_bytestring(0,11,0)
                  , cdataF = \(BS ForeignPtr Word8
    cdata_start Int
    cdata_len) -> do
    #else
                  , cdataF = \(PS _ cdata_start cdata_len) -> do
    #endif
                     let tag :: Int
    tag = Int
    0x03
                     index <- URef s Int -> ST s (RefElement (URef s Int))
    forall c (m :: * -> *).
    (MutableRef c, PrimMonad m, PrimState m ~ MCState c) =>
    c -> m (RefElement c)
    forall (m :: * -> *).
    (PrimMonad m, PrimState m ~ MCState (URef s Int)) =>
    URef s Int -> m (RefElement (URef s Int))
    readRef URef s Int
    sizeRef
                     v' <-
                       do v <- readSTRef vecRef
                          if index + 3 < UMV.length v
                            then pure v
                            else do
                              v' <- UMV.grow v (UMV.length v)
                              writeSTRef vecRef v'
                              return v'
                     do writeRef sizeRef (index + 3)
                     do UMV.write v' index tag
                        UMV.write v' (index + 1) (distance cdata_start offset0)
                        UMV.write v' (index + 2) cdata_len
                  } str
                wet <- readSTRef vecRef
                arr <- UV.unsafeFreeze wet
                size <- readRef sizeRef
                return (UV.unsafeSlice 0 size arr))

    untilM :: Monad m => m Bool -> m ()
    untilM :: forall (m :: * -> *). Monad m => m Bool -> m ()
    untilM m Bool
    loop = do
      cond <- m Bool
    loop
      case cond of
        Bool
    True  -> () -> m ()
    forall a. a -> m a
    forall (m :: * -> *) a. Monad m => a -> m a
    return ()
        Bool
    False -> m Bool -> m ()
    forall (m :: * -> *). Monad m => m Bool -> m ()
    untilM m Bool
    loop

    #if MIN_VERSION_bytestring(0,11,0)
    minusForeignPtr :: ForeignPtr a -> ForeignPtr b -> Int
    minusForeignPtr :: forall a b. ForeignPtr a -> ForeignPtr b -> Int
    minusForeignPtr ForeignPtr a
    fpA ForeignPtr b
    fpB = IO Int -> Int
    forall a. IO a -> a
    unsafeDupablePerformIO (IO Int -> Int) -> IO Int -> Int
    forall a b. (a -> b) -> a -> b
    $
      ForeignPtr a -> (Ptr a -> IO Int) -> IO Int
    forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
    withForeignPtr ForeignPtr a
    fpA ((Ptr a -> IO Int) -> IO Int) -> (Ptr a -> IO Int) -> IO Int
    forall a b. (a -> b) -> a -> b
    $ \Ptr a
    ptrA -> ForeignPtr b -> (Ptr b -> IO Int) -> IO Int
    forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
    withForeignPtr ForeignPtr b
    fpB ((Ptr b -> IO Int) -> IO Int) -> (Ptr b -> IO Int) -> IO Int
    forall a b. (a -> b) -> a -> b
    $ \Ptr b
    ptrB ->
        Int -> IO Int
    forall a. a -> IO a
    forall (f :: * -> *) a. Applicative f => a -> f a
    pure (Ptr a -> Ptr b -> Int
    forall a b. Ptr a -> Ptr b -> Int
    minusPtr Ptr a
    ptrA Ptr b
    ptrB)

    distance :: ForeignPtr a -> ForeignPtr b -> Int
    distance :: forall a b. ForeignPtr a -> ForeignPtr b -> Int
    distance = ForeignPtr a -> ForeignPtr b -> Int
    forall a b. ForeignPtr a -> ForeignPtr b -> Int
    minusForeignPtr
    #else
    distance :: Int -> Int -> Int
    distance a b = a - b
    #endif