diff --git a/Data/Vector.hs b/Data/Vector.hs
--- a/Data/Vector.hs
+++ b/Data/Vector.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE CPP
+           , DeriveDataTypeable
            , FlexibleInstances
            , MultiParamTypeClasses
            , TypeFamilies
@@ -14,7 +15,7 @@
 -- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
 -- Stability   : experimental
 -- Portability : non-portable
--- 
+--
 -- A library for boxed vectors (that is, polymorphic arrays capable of
 -- holding any Haskell value). The vectors come in two flavours:
 --
@@ -80,7 +81,7 @@
   accum, accumulate, accumulate_,
   unsafeAccum, unsafeAccumulate, unsafeAccumulate_,
 
-  -- ** Permutations 
+  -- ** Permutations
   reverse, backpermute, unsafeBackpermute,
 
   -- ** Safe destructive updates
@@ -95,7 +96,7 @@
   map, imap, concatMap,
 
   -- ** Monadic mapping
-  mapM, mapM_, forM, forM_,
+  mapM, imapM, mapM_, imapM_, forM, forM_,
 
   -- ** Zipping
   zipWith, zipWith3, zipWith4, zipWith5, zipWith6,
@@ -103,7 +104,7 @@
   zip, zip3, zip4, zip5, zip6,
 
   -- ** Monadic zipping
-  zipWithM, zipWithM_,
+  zipWithM, izipWithM, zipWithM_, izipWithM_,
 
   -- ** Unzipping
   unzip, unzip3, unzip4, unzip5, unzip6,
@@ -131,8 +132,9 @@
   minIndex, minIndexBy, maxIndex, maxIndexBy,
 
   -- ** Monadic folds
-  foldM, foldM', fold1M, fold1M',
-  foldM_, foldM'_, fold1M_, fold1M'_,
+  foldM, ifoldM, foldM', ifoldM',
+  fold1M, fold1M',foldM_, ifoldM_,
+  foldM'_, ifoldM'_, fold1M_, fold1M'_,
 
   -- ** Monadic sequencing
   sequence, sequence_,
@@ -160,7 +162,7 @@
 import qualified Data.Vector.Generic as G
 import           Data.Vector.Mutable  ( MVector(..) )
 import           Data.Primitive.Array
-import qualified Data.Vector.Fusion.Stream as Stream
+import qualified Data.Vector.Fusion.Bundle as Bundle
 
 import Control.DeepSeq ( NFData, rnf )
 import Control.Monad ( MonadPlus(..), liftM, ap )
@@ -181,8 +183,6 @@
                         enumFromTo, enumFromThenTo,
                         mapM, mapM_, sequence, sequence_ )
 
-import qualified Prelude
-
 import Data.Typeable ( Typeable )
 import Data.Data     ( Data(..) )
 import Text.Read     ( Read(..), readListPrecDefault )
@@ -193,9 +193,10 @@
 import qualified Data.Traversable as Traversable
 
 #if __GLASGOW_HASKELL__ >= 708
-import qualified GHC.Exts as Exts
+import qualified GHC.Exts as Exts (IsList(..))
 #endif
 
+
 -- | Boxed vectors, supporting efficient slicing.
 data Vector a = Vector {-# UNPACK #-} !Int
                        {-# UNPACK #-} !Int
@@ -203,9 +204,9 @@
         deriving ( Typeable )
 
 instance NFData a => NFData (Vector a) where
-    rnf (Vector i n arr) = force i
+    rnf (Vector i n arr) = rnfAll i
         where
-          force !ix | ix < n    = rnf (indexArray arr ix) `seq` force (ix+1)
+          rnfAll ix | ix < n    = rnf (indexArray arr ix) `seq` rnfAll (ix+1)
                     | otherwise = ()
 
 instance Show a => Show (Vector a) where
@@ -216,6 +217,7 @@
   readListPrec = readListPrecDefault
 
 #if __GLASGOW_HASKELL__ >= 708
+
 instance Exts.IsList (Vector a) where
   type Item (Vector a) = a
   fromList = fromList
@@ -257,27 +259,27 @@
 -- See http://trac.haskell.org/vector/ticket/12
 instance Eq a => Eq (Vector a) where
   {-# INLINE (==) #-}
-  xs == ys = Stream.eq (G.stream xs) (G.stream ys)
+  xs == ys = Bundle.eq (G.stream xs) (G.stream ys)
 
   {-# INLINE (/=) #-}
-  xs /= ys = not (Stream.eq (G.stream xs) (G.stream ys))
+  xs /= ys = not (Bundle.eq (G.stream xs) (G.stream ys))
 
 -- See http://trac.haskell.org/vector/ticket/12
 instance Ord a => Ord (Vector a) where
   {-# INLINE compare #-}
-  compare xs ys = Stream.cmp (G.stream xs) (G.stream ys)
+  compare xs ys = Bundle.cmp (G.stream xs) (G.stream ys)
 
   {-# INLINE (<) #-}
-  xs < ys = Stream.cmp (G.stream xs) (G.stream ys) == LT
+  xs < ys = Bundle.cmp (G.stream xs) (G.stream ys) == LT
 
   {-# INLINE (<=) #-}
-  xs <= ys = Stream.cmp (G.stream xs) (G.stream ys) /= GT
+  xs <= ys = Bundle.cmp (G.stream xs) (G.stream ys) /= GT
 
   {-# INLINE (>) #-}
-  xs > ys = Stream.cmp (G.stream xs) (G.stream ys) == GT
+  xs > ys = Bundle.cmp (G.stream xs) (G.stream ys) == GT
 
   {-# INLINE (>=) #-}
-  xs >= ys = Stream.cmp (G.stream xs) (G.stream ys) /= LT
+  xs >= ys = Bundle.cmp (G.stream xs) (G.stream ys) /= LT
 
 instance Monoid (Vector a) where
   {-# INLINE mempty #-}
@@ -300,6 +302,9 @@
   {-# INLINE (>>=) #-}
   (>>=) = flip concatMap
 
+  {-# INLINE fail #-}
+  fail _ = empty
+
 instance MonadPlus Vector where
   {-# INLINE mzero #-}
   mzero = empty
@@ -327,7 +332,7 @@
 
   {-# INLINE foldl #-}
   foldl = foldl
-  
+
   {-# INLINE foldr1 #-}
   foldr1 = foldr1
 
@@ -710,7 +715,7 @@
 -- > <5,9,2,7> // [(2,1),(0,3),(2,8)] = <3,9,8,7>
 --
 (//) :: Vector a   -- ^ initial vector (of length @m@)
-                -> [(Int, a)] -- ^ list of index/value pairs (of length @n@) 
+                -> [(Int, a)] -- ^ list of index/value pairs (of length @n@)
                 -> Vector a
 {-# INLINE (//) #-}
 (//) = (G.//)
@@ -893,12 +898,24 @@
 {-# INLINE mapM #-}
 mapM = G.mapM
 
+-- | /O(n)/ Apply the monadic action to every element of a vector and its
+-- index, yielding a vector of results
+imapM :: Monad m => (Int -> a -> m b) -> Vector a -> m (Vector b)
+{-# INLINE imapM #-}
+imapM = G.imapM
+
 -- | /O(n)/ Apply the monadic action to all elements of a vector and ignore the
 -- results
 mapM_ :: Monad m => (a -> m b) -> Vector a -> m ()
 {-# INLINE mapM_ #-}
 mapM_ = G.mapM_
 
+-- | /O(n)/ Apply the monadic action to every element of a vector and its
+-- index, ignoring the results
+imapM_ :: Monad m => (Int -> a -> m b) -> Vector a -> m ()
+{-# INLINE imapM_ #-}
+imapM_ = G.imapM_
+
 -- | /O(n)/ Apply the monadic action to all elements of the vector, yielding a
 -- vector of results. Equvalent to @flip 'mapM'@.
 forM :: Monad m => Vector a -> (a -> m b) -> m (Vector b)
@@ -970,7 +987,7 @@
 {-# INLINE izipWith6 #-}
 izipWith6 = G.izipWith6
 
--- | Elementwise pairing of array elements. 
+-- | Elementwise pairing of array elements.
 zip :: Vector a -> Vector b -> Vector (a, b)
 {-# INLINE zip #-}
 zip = G.zip
@@ -1030,12 +1047,24 @@
 {-# INLINE zipWithM #-}
 zipWithM = G.zipWithM
 
+-- | /O(min(m,n))/ Zip the two vectors with a monadic action that also takes
+-- the element index and yield a vector of results
+izipWithM :: Monad m => (Int -> a -> b -> m c) -> Vector a -> Vector b -> m (Vector c)
+{-# INLINE izipWithM #-}
+izipWithM = G.izipWithM
+
 -- | /O(min(m,n))/ Zip the two vectors with the monadic action and ignore the
 -- results
 zipWithM_ :: Monad m => (a -> b -> m c) -> Vector a -> Vector b -> m ()
 {-# INLINE zipWithM_ #-}
 zipWithM_ = G.zipWithM_
 
+-- | /O(min(m,n))/ Zip the two vectors with a monadic action that also takes
+-- the element index and ignore the results
+izipWithM_ :: Monad m => (Int -> a -> b -> m c) -> Vector a -> Vector b -> m ()
+{-# INLINE izipWithM_ #-}
+izipWithM_ = G.izipWithM_
+
 -- Filtering
 -- ---------
 
@@ -1298,6 +1327,11 @@
 {-# INLINE foldM #-}
 foldM = G.foldM
 
+-- | /O(n)/ Monadic fold (action applied to each element and its index)
+ifoldM :: Monad m => (a -> Int -> b -> m a) -> a -> Vector b -> m a
+{-# INLINE ifoldM #-}
+ifoldM = G.ifoldM
+
 -- | /O(n)/ Monadic fold over non-empty vectors
 fold1M :: Monad m => (a -> a -> m a) -> Vector a -> m a
 {-# INLINE fold1M #-}
@@ -1308,6 +1342,12 @@
 {-# INLINE foldM' #-}
 foldM' = G.foldM'
 
+-- | /O(n)/ Monadic fold with strict accumulator (action applied to each
+-- element and its index)
+ifoldM' :: Monad m => (a -> Int -> b -> m a) -> a -> Vector b -> m a
+{-# INLINE ifoldM' #-}
+ifoldM' = G.ifoldM'
+
 -- | /O(n)/ Monadic fold over non-empty vectors with strict accumulator
 fold1M' :: Monad m => (a -> a -> m a) -> Vector a -> m a
 {-# INLINE fold1M' #-}
@@ -1318,6 +1358,12 @@
 {-# INLINE foldM_ #-}
 foldM_ = G.foldM_
 
+-- | /O(n)/ Monadic fold that discards the result (action applied to each
+-- element and its index)
+ifoldM_ :: Monad m => (a -> Int -> b -> m a) -> a -> Vector b -> m ()
+{-# INLINE ifoldM_ #-}
+ifoldM_ = G.ifoldM_
+
 -- | /O(n)/ Monadic fold over non-empty vectors that discards the result
 fold1M_ :: Monad m => (a -> a -> m a) -> Vector a -> m ()
 {-# INLINE fold1M_ #-}
@@ -1328,6 +1374,12 @@
 {-# INLINE foldM'_ #-}
 foldM'_ = G.foldM'_
 
+-- | /O(n)/ Monadic fold with strict accumulator that discards the result
+-- (action applied to each element and its index)
+ifoldM'_ :: Monad m => (a -> Int -> b -> m a) -> a -> Vector b -> m ()
+{-# INLINE ifoldM'_ #-}
+ifoldM'_ = G.ifoldM'_
+
 -- | /O(n)/ Monadic fold over non-empty vectors with strict accumulator
 -- that discards the result
 fold1M'_ :: Monad m => (a -> a -> m a) -> Vector a -> m ()
@@ -1391,7 +1443,7 @@
 -- >         yi = f y(i-1) x(i-1)
 --
 -- Example: @scanl (+) 0 \<1,2,3,4\> = \<0,1,3,6,10\>@
--- 
+--
 scanl :: (a -> b -> a) -> a -> Vector b -> Vector a
 {-# INLINE scanl #-}
 scanl = G.scanl
@@ -1514,7 +1566,7 @@
 unsafeCopy :: PrimMonad m => MVector (PrimState m) a -> Vector a -> m ()
 {-# INLINE unsafeCopy #-}
 unsafeCopy = G.unsafeCopy
-           
+
 -- | /O(n)/ Copy an immutable vector into a mutable one. The two vectors must
 -- have the same length.
 copy :: PrimMonad m => MVector (PrimState m) a -> Vector a -> m ()
diff --git a/Data/Vector/Fusion/Bundle.hs b/Data/Vector/Fusion/Bundle.hs
new file mode 100644
--- /dev/null
+++ b/Data/Vector/Fusion/Bundle.hs
@@ -0,0 +1,633 @@
+{-# LANGUAGE CPP, FlexibleInstances, Rank2Types, BangPatterns #-}
+
+-- |
+-- Module      : Data.Vector.Fusion.Bundle
+-- Copyright   : (c) Roman Leshchinskiy 2008-2010
+-- License     : BSD-style
+--
+-- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
+-- Stability   : experimental
+-- Portability : non-portable
+--
+-- Bundles for stream fusion
+--
+
+module Data.Vector.Fusion.Bundle (
+  -- * Types
+  Step(..), Chunk(..), Bundle, MBundle,
+
+  -- * In-place markers
+  inplace,
+
+  -- * Size hints
+  size, sized,
+
+  -- * Length information
+  length, null,
+
+  -- * Construction
+  empty, singleton, cons, snoc, replicate, generate, (++),
+
+  -- * Accessing individual elements
+  head, last, (!!), (!?),
+
+  -- * Substreams
+  slice, init, tail, take, drop,
+
+  -- * Mapping
+  map, concatMap, flatten, unbox,
+
+  -- * Zipping
+  indexed, indexedR,
+  zipWith, zipWith3, zipWith4, zipWith5, zipWith6,
+  zip, zip3, zip4, zip5, zip6,
+
+  -- * Filtering
+  filter, takeWhile, dropWhile,
+
+  -- * Searching
+  elem, notElem, find, findIndex,
+
+  -- * Folding
+  foldl, foldl1, foldl', foldl1', foldr, foldr1,
+
+  -- * Specialised folds
+  and, or,
+
+  -- * Unfolding
+  unfoldr, unfoldrN, iterateN,
+
+  -- * Scans
+  prescanl, prescanl',
+  postscanl, postscanl',
+  scanl, scanl',
+  scanl1, scanl1',
+
+  -- * Enumerations
+  enumFromStepN, enumFromTo, enumFromThenTo,
+
+  -- * Conversions
+  toList, fromList, fromListN, unsafeFromList, lift,
+  fromVector, reVector, fromVectors, concatVectors,
+
+  -- * Monadic combinators
+  mapM, mapM_, zipWithM, zipWithM_, filterM, foldM, fold1M, foldM', fold1M',
+
+  eq, cmp
+) where
+
+import Data.Vector.Generic.Base ( Vector )
+import Data.Vector.Fusion.Bundle.Size
+import Data.Vector.Fusion.Util
+import Data.Vector.Fusion.Stream.Monadic ( Stream(..), Step(..) )
+import Data.Vector.Fusion.Bundle.Monadic ( Chunk(..) )
+import qualified Data.Vector.Fusion.Bundle.Monadic as M
+import qualified Data.Vector.Fusion.Stream.Monadic as S
+
+import Prelude hiding ( length, null,
+                        replicate, (++),
+                        head, last, (!!),
+                        init, tail, take, drop,
+                        map, concatMap,
+                        zipWith, zipWith3, zip, zip3,
+                        filter, takeWhile, dropWhile,
+                        elem, notElem,
+                        foldl, foldl1, foldr, foldr1,
+                        and, or,
+                        scanl, scanl1,
+                        enumFromTo, enumFromThenTo,
+                        mapM, mapM_ )
+
+import GHC.Base ( build )
+
+-- Data.Vector.Internal.Check is unused
+#define NOT_VECTOR_MODULE
+#include "vector.h"
+
+-- | The type of pure streams
+type Bundle = M.Bundle Id
+
+-- | Alternative name for monadic streams
+type MBundle = M.Bundle
+
+inplace :: (forall m. Monad m => S.Stream m a -> S.Stream m b)
+	-> (Size -> Size) -> Bundle v a -> Bundle v b
+{-# INLINE_FUSED inplace #-}
+inplace f g b = b `seq` M.fromStream (f (M.elements b)) (g (M.size b))
+
+{-# RULES
+
+"inplace/inplace [Vector]"
+  forall (f1 :: forall m. Monad m => S.Stream m a -> S.Stream m a)
+         (f2 :: forall m. Monad m => S.Stream m a -> S.Stream m a)
+         g1 g2 s.
+  inplace f1 g1 (inplace f2 g2 s) = inplace (f1 . f2) (g1 . g2) s   #-}
+
+
+
+-- | Convert a pure stream to a monadic stream
+lift :: Monad m => Bundle v a -> M.Bundle m v a
+{-# INLINE_FUSED lift #-}
+lift (M.Bundle (Stream step s) (Stream vstep t) v sz)
+    = M.Bundle (Stream (return . unId . step) s)
+               (Stream (return . unId . vstep) t) v sz
+
+-- | 'Size' hint of a 'Bundle'
+size :: Bundle v a -> Size
+{-# INLINE size #-}
+size = M.size
+
+-- | Attach a 'Size' hint to a 'Bundle'
+sized :: Bundle v a -> Size -> Bundle v a
+{-# INLINE sized #-}
+sized = M.sized
+
+-- Length
+-- ------
+
+-- | Length of a 'Bundle'
+length :: Bundle v a -> Int
+{-# INLINE length #-}
+length = unId . M.length
+
+-- | Check if a 'Bundle' is empty
+null :: Bundle v a -> Bool
+{-# INLINE null #-}
+null = unId . M.null
+
+-- Construction
+-- ------------
+
+-- | Empty 'Bundle'
+empty :: Bundle v a
+{-# INLINE empty #-}
+empty = M.empty
+
+-- | Singleton 'Bundle'
+singleton :: a -> Bundle v a
+{-# INLINE singleton #-}
+singleton = M.singleton
+
+-- | Replicate a value to a given length
+replicate :: Int -> a -> Bundle v a
+{-# INLINE replicate #-}
+replicate = M.replicate
+
+-- | Generate a stream from its indices
+generate :: Int -> (Int -> a) -> Bundle v a
+{-# INLINE generate #-}
+generate = M.generate
+
+-- | Prepend an element
+cons :: a -> Bundle v a -> Bundle v a
+{-# INLINE cons #-}
+cons = M.cons
+
+-- | Append an element
+snoc :: Bundle v a -> a -> Bundle v a
+{-# INLINE snoc #-}
+snoc = M.snoc
+
+infixr 5 ++
+-- | Concatenate two 'Bundle's
+(++) :: Bundle v a -> Bundle v a -> Bundle v a
+{-# INLINE (++) #-}
+(++) = (M.++)
+
+-- Accessing elements
+-- ------------------
+
+-- | First element of the 'Bundle' or error if empty
+head :: Bundle v a -> a
+{-# INLINE head #-}
+head = unId . M.head
+
+-- | Last element of the 'Bundle' or error if empty
+last :: Bundle v a -> a
+{-# INLINE last #-}
+last = unId . M.last
+
+infixl 9 !!
+-- | Element at the given position
+(!!) :: Bundle v a -> Int -> a
+{-# INLINE (!!) #-}
+s !! i = unId (s M.!! i)
+
+infixl 9 !?
+-- | Element at the given position or 'Nothing' if out of bounds
+(!?) :: Bundle v a -> Int -> Maybe a
+{-# INLINE (!?) #-}
+s !? i = unId (s M.!? i)
+
+-- Substreams
+-- ----------
+
+-- | Extract a substream of the given length starting at the given position.
+slice :: Int   -- ^ starting index
+      -> Int   -- ^ length
+      -> Bundle v a
+      -> Bundle v a
+{-# INLINE slice #-}
+slice = M.slice
+
+-- | All but the last element
+init :: Bundle v a -> Bundle v a
+{-# INLINE init #-}
+init = M.init
+
+-- | All but the first element
+tail :: Bundle v a -> Bundle v a
+{-# INLINE tail #-}
+tail = M.tail
+
+-- | The first @n@ elements
+take :: Int -> Bundle v a -> Bundle v a
+{-# INLINE take #-}
+take = M.take
+
+-- | All but the first @n@ elements
+drop :: Int -> Bundle v a -> Bundle v a
+{-# INLINE drop #-}
+drop = M.drop
+
+-- Mapping
+-- ---------------
+
+-- | Map a function over a 'Bundle'
+map :: (a -> b) -> Bundle v a -> Bundle v b
+{-# INLINE map #-}
+map = M.map
+
+unbox :: Bundle v (Box a) -> Bundle v a
+{-# INLINE unbox #-}
+unbox = M.unbox
+
+concatMap :: (a -> Bundle v b) -> Bundle v a -> Bundle v b
+{-# INLINE concatMap #-}
+concatMap = M.concatMap
+
+-- Zipping
+-- -------
+
+-- | Pair each element in a 'Bundle' with its index
+indexed :: Bundle v a -> Bundle v (Int,a)
+{-# INLINE indexed #-}
+indexed = M.indexed
+
+-- | Pair each element in a 'Bundle' with its index, starting from the right
+-- and counting down
+indexedR :: Int -> Bundle v a -> Bundle v (Int,a)
+{-# INLINE_FUSED indexedR #-}
+indexedR = M.indexedR
+
+-- | Zip two 'Bundle's with the given function
+zipWith :: (a -> b -> c) -> Bundle v a -> Bundle v b -> Bundle v c
+{-# INLINE zipWith #-}
+zipWith = M.zipWith
+
+-- | Zip three 'Bundle's with the given function
+zipWith3 :: (a -> b -> c -> d) -> Bundle v a -> Bundle v b -> Bundle v c -> Bundle v d
+{-# INLINE zipWith3 #-}
+zipWith3 = M.zipWith3
+
+zipWith4 :: (a -> b -> c -> d -> e)
+                    -> Bundle v a -> Bundle v b -> Bundle v c -> Bundle v d
+                    -> Bundle v e
+{-# INLINE zipWith4 #-}
+zipWith4 = M.zipWith4
+
+zipWith5 :: (a -> b -> c -> d -> e -> f)
+                    -> Bundle v a -> Bundle v b -> Bundle v c -> Bundle v d
+                    -> Bundle v e -> Bundle v f
+{-# INLINE zipWith5 #-}
+zipWith5 = M.zipWith5
+
+zipWith6 :: (a -> b -> c -> d -> e -> f -> g)
+                    -> Bundle v a -> Bundle v b -> Bundle v c -> Bundle v d
+                    -> Bundle v e -> Bundle v f -> Bundle v g
+{-# INLINE zipWith6 #-}
+zipWith6 = M.zipWith6
+
+zip :: Bundle v a -> Bundle v b -> Bundle v (a,b)
+{-# INLINE zip #-}
+zip = M.zip
+
+zip3 :: Bundle v a -> Bundle v b -> Bundle v c -> Bundle v (a,b,c)
+{-# INLINE zip3 #-}
+zip3 = M.zip3
+
+zip4 :: Bundle v a -> Bundle v b -> Bundle v c -> Bundle v d
+                -> Bundle v (a,b,c,d)
+{-# INLINE zip4 #-}
+zip4 = M.zip4
+
+zip5 :: Bundle v a -> Bundle v b -> Bundle v c -> Bundle v d
+                -> Bundle v e -> Bundle v (a,b,c,d,e)
+{-# INLINE zip5 #-}
+zip5 = M.zip5
+
+zip6 :: Bundle v a -> Bundle v b -> Bundle v c -> Bundle v d
+                -> Bundle v e -> Bundle v f -> Bundle v (a,b,c,d,e,f)
+{-# INLINE zip6 #-}
+zip6 = M.zip6
+
+-- Filtering
+-- ---------
+
+-- | Drop elements which do not satisfy the predicate
+filter :: (a -> Bool) -> Bundle v a -> Bundle v a
+{-# INLINE filter #-}
+filter = M.filter
+
+-- | Longest prefix of elements that satisfy the predicate
+takeWhile :: (a -> Bool) -> Bundle v a -> Bundle v a
+{-# INLINE takeWhile #-}
+takeWhile = M.takeWhile
+
+-- | Drop the longest prefix of elements that satisfy the predicate
+dropWhile :: (a -> Bool) -> Bundle v a -> Bundle v a
+{-# INLINE dropWhile #-}
+dropWhile = M.dropWhile
+
+-- Searching
+-- ---------
+
+infix 4 `elem`
+-- | Check whether the 'Bundle' contains an element
+elem :: Eq a => a -> Bundle v a -> Bool
+{-# INLINE elem #-}
+elem x = unId . M.elem x
+
+infix 4 `notElem`
+-- | Inverse of `elem`
+notElem :: Eq a => a -> Bundle v a -> Bool
+{-# INLINE notElem #-}
+notElem x = unId . M.notElem x
+
+-- | Yield 'Just' the first element matching the predicate or 'Nothing' if no
+-- such element exists.
+find :: (a -> Bool) -> Bundle v a -> Maybe a
+{-# INLINE find #-}
+find f = unId . M.find f
+
+-- | Yield 'Just' the index of the first element matching the predicate or
+-- 'Nothing' if no such element exists.
+findIndex :: (a -> Bool) -> Bundle v a -> Maybe Int
+{-# INLINE findIndex #-}
+findIndex f = unId . M.findIndex f
+
+-- Folding
+-- -------
+
+-- | Left fold
+foldl :: (a -> b -> a) -> a -> Bundle v b -> a
+{-# INLINE foldl #-}
+foldl f z = unId . M.foldl f z
+
+-- | Left fold on non-empty 'Bundle's
+foldl1 :: (a -> a -> a) -> Bundle v a -> a
+{-# INLINE foldl1 #-}
+foldl1 f = unId . M.foldl1 f
+
+-- | Left fold with strict accumulator
+foldl' :: (a -> b -> a) -> a -> Bundle v b -> a
+{-# INLINE foldl' #-}
+foldl' f z = unId . M.foldl' f z
+
+-- | Left fold on non-empty 'Bundle's with strict accumulator
+foldl1' :: (a -> a -> a) -> Bundle v a -> a
+{-# INLINE foldl1' #-}
+foldl1' f = unId . M.foldl1' f
+
+-- | Right fold
+foldr :: (a -> b -> b) -> b -> Bundle v a -> b
+{-# INLINE foldr #-}
+foldr f z = unId . M.foldr f z
+
+-- | Right fold on non-empty 'Bundle's
+foldr1 :: (a -> a -> a) -> Bundle v a -> a
+{-# INLINE foldr1 #-}
+foldr1 f = unId . M.foldr1 f
+
+-- Specialised folds
+-- -----------------
+
+and :: Bundle v Bool -> Bool
+{-# INLINE and #-}
+and = unId . M.and
+
+or :: Bundle v Bool -> Bool
+{-# INLINE or #-}
+or = unId . M.or
+
+-- Unfolding
+-- ---------
+
+-- | Unfold
+unfoldr :: (s -> Maybe (a, s)) -> s -> Bundle v a
+{-# INLINE unfoldr #-}
+unfoldr = M.unfoldr
+
+-- | Unfold at most @n@ elements
+unfoldrN :: Int -> (s -> Maybe (a, s)) -> s -> Bundle v a
+{-# INLINE unfoldrN #-}
+unfoldrN = M.unfoldrN
+
+-- | Apply function n-1 times to value. Zeroth element is original value.
+iterateN :: Int -> (a -> a) -> a -> Bundle v a
+{-# INLINE iterateN #-}
+iterateN = M.iterateN
+
+-- Scans
+-- -----
+
+-- | Prefix scan
+prescanl :: (a -> b -> a) -> a -> Bundle v b -> Bundle v a
+{-# INLINE prescanl #-}
+prescanl = M.prescanl
+
+-- | Prefix scan with strict accumulator
+prescanl' :: (a -> b -> a) -> a -> Bundle v b -> Bundle v a
+{-# INLINE prescanl' #-}
+prescanl' = M.prescanl'
+
+-- | Suffix scan
+postscanl :: (a -> b -> a) -> a -> Bundle v b -> Bundle v a
+{-# INLINE postscanl #-}
+postscanl = M.postscanl
+
+-- | Suffix scan with strict accumulator
+postscanl' :: (a -> b -> a) -> a -> Bundle v b -> Bundle v a
+{-# INLINE postscanl' #-}
+postscanl' = M.postscanl'
+
+-- | Haskell-style scan
+scanl :: (a -> b -> a) -> a -> Bundle v b -> Bundle v a
+{-# INLINE scanl #-}
+scanl = M.scanl
+
+-- | Haskell-style scan with strict accumulator
+scanl' :: (a -> b -> a) -> a -> Bundle v b -> Bundle v a
+{-# INLINE scanl' #-}
+scanl' = M.scanl'
+
+-- | Scan over a non-empty 'Bundle'
+scanl1 :: (a -> a -> a) -> Bundle v a -> Bundle v a
+{-# INLINE scanl1 #-}
+scanl1 = M.scanl1
+
+-- | Scan over a non-empty 'Bundle' with a strict accumulator
+scanl1' :: (a -> a -> a) -> Bundle v a -> Bundle v a
+{-# INLINE scanl1' #-}
+scanl1' = M.scanl1'
+
+
+-- Comparisons
+-- -----------
+
+-- | Check if two 'Bundle's are equal
+eq :: Eq a => Bundle v a -> Bundle v a -> Bool
+{-# INLINE eq #-}
+eq x y = unId (M.eq x y)
+
+-- | Lexicographically compare two 'Bundle's
+cmp :: Ord a => Bundle v a -> Bundle v a -> Ordering
+{-# INLINE cmp #-}
+cmp x y = unId (M.cmp x y)
+
+instance Eq a => Eq (M.Bundle Id v a) where
+  {-# INLINE (==) #-}
+  (==) = eq
+
+instance Ord a => Ord (M.Bundle Id v a) where
+  {-# INLINE compare #-}
+  compare = cmp
+
+-- Monadic combinators
+-- -------------------
+
+-- | Apply a monadic action to each element of the stream, producing a monadic
+-- stream of results
+mapM :: Monad m => (a -> m b) -> Bundle v a -> M.Bundle m v b
+{-# INLINE mapM #-}
+mapM f = M.mapM f . lift
+
+-- | Apply a monadic action to each element of the stream
+mapM_ :: Monad m => (a -> m b) -> Bundle v a -> m ()
+{-# INLINE mapM_ #-}
+mapM_ f = M.mapM_ f . lift
+
+zipWithM :: Monad m => (a -> b -> m c) -> Bundle v a -> Bundle v b -> M.Bundle m v c
+{-# INLINE zipWithM #-}
+zipWithM f as bs = M.zipWithM f (lift as) (lift bs)
+
+zipWithM_ :: Monad m => (a -> b -> m c) -> Bundle v a -> Bundle v b -> m ()
+{-# INLINE zipWithM_ #-}
+zipWithM_ f as bs = M.zipWithM_ f (lift as) (lift bs)
+
+-- | Yield a monadic stream of elements that satisfy the monadic predicate
+filterM :: Monad m => (a -> m Bool) -> Bundle v a -> M.Bundle m v a
+{-# INLINE filterM #-}
+filterM f = M.filterM f . lift
+
+-- | Monadic fold
+foldM :: Monad m => (a -> b -> m a) -> a -> Bundle v b -> m a
+{-# INLINE foldM #-}
+foldM m z = M.foldM m z . lift
+
+-- | Monadic fold over non-empty stream
+fold1M :: Monad m => (a -> a -> m a) -> Bundle v a -> m a
+{-# INLINE fold1M #-}
+fold1M m = M.fold1M m . lift
+
+-- | Monadic fold with strict accumulator
+foldM' :: Monad m => (a -> b -> m a) -> a -> Bundle v b -> m a
+{-# INLINE foldM' #-}
+foldM' m z = M.foldM' m z . lift
+
+-- | Monad fold over non-empty stream with strict accumulator
+fold1M' :: Monad m => (a -> a -> m a) -> Bundle v a -> m a
+{-# INLINE fold1M' #-}
+fold1M' m = M.fold1M' m . lift
+
+-- Enumerations
+-- ------------
+
+-- | Yield a 'Bundle' of the given length containing the values @x@, @x+y@,
+-- @x+y+y@ etc.
+enumFromStepN :: Num a => a -> a -> Int -> Bundle v a
+{-# INLINE enumFromStepN #-}
+enumFromStepN = M.enumFromStepN
+
+-- | Enumerate values
+--
+-- /WARNING:/ This operations can be very inefficient. If at all possible, use
+-- 'enumFromStepN' instead.
+enumFromTo :: Enum a => a -> a -> Bundle v a
+{-# INLINE enumFromTo #-}
+enumFromTo = M.enumFromTo
+
+-- | Enumerate values with a given step.
+--
+-- /WARNING:/ This operations is very inefficient. If at all possible, use
+-- 'enumFromStepN' instead.
+enumFromThenTo :: Enum a => a -> a -> a -> Bundle v a
+{-# INLINE enumFromThenTo #-}
+enumFromThenTo = M.enumFromThenTo
+
+-- Conversions
+-- -----------
+
+-- | Convert a 'Bundle' to a list
+toList :: Bundle v a -> [a]
+{-# INLINE toList #-}
+-- toList s = unId (M.toList s)
+toList s = build (\c n -> toListFB c n s)
+
+-- This supports foldr/build list fusion that GHC implements
+toListFB :: (a -> b -> b) -> b -> Bundle v a -> b
+{-# INLINE [0] toListFB #-}
+toListFB c n M.Bundle{M.sElems = Stream step t} = go t
+  where
+    go s = case unId (step s) of
+             Yield x s' -> x `c` go s'
+             Skip    s' -> go s'
+             Done       -> n
+
+-- | Create a 'Bundle' from a list
+fromList :: [a] -> Bundle v a
+{-# INLINE fromList #-}
+fromList = M.fromList
+
+-- | Create a 'Bundle' from the first @n@ elements of a list
+--
+-- > fromListN n xs = fromList (take n xs)
+fromListN :: Int -> [a] -> Bundle v a
+{-# INLINE fromListN #-}
+fromListN = M.fromListN
+
+unsafeFromList :: Size -> [a] -> Bundle v a
+{-# INLINE unsafeFromList #-}
+unsafeFromList = M.unsafeFromList
+
+fromVector :: Vector v a => v a -> Bundle v a
+{-# INLINE fromVector #-}
+fromVector = M.fromVector
+
+reVector :: Bundle u a -> Bundle v a
+{-# INLINE reVector #-}
+reVector = M.reVector
+
+fromVectors :: Vector v a => [v a] -> Bundle v a
+{-# INLINE fromVectors #-}
+fromVectors = M.fromVectors
+
+concatVectors :: Vector v a => Bundle u (v a) -> Bundle v a
+{-# INLINE concatVectors #-}
+concatVectors = M.concatVectors
+
+-- | Create a 'Bundle' of values from a 'Bundle' of streamable things
+flatten :: (a -> s) -> (s -> Step s b) -> Size -> Bundle v a -> Bundle v b
+{-# INLINE_FUSED flatten #-}
+flatten mk istep sz = M.flatten (return . mk) (return . istep) sz . lift
+
diff --git a/Data/Vector/Fusion/Bundle/Monadic.hs b/Data/Vector/Fusion/Bundle/Monadic.hs
new file mode 100644
--- /dev/null
+++ b/Data/Vector/Fusion/Bundle/Monadic.hs
@@ -0,0 +1,1098 @@
+{-# LANGUAGE CPP, ExistentialQuantification, MultiParamTypeClasses, FlexibleInstances, Rank2Types, BangPatterns, KindSignatures, GADTs, ScopedTypeVariables #-}
+
+-- |
+-- Module      : Data.Vector.Fusion.Bundle.Monadic
+-- Copyright   : (c) Roman Leshchinskiy 2008-2010
+-- License     : BSD-style
+--
+-- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
+-- Stability   : experimental
+-- Portability : non-portable
+--
+-- Monadic bundles.
+--
+
+module Data.Vector.Fusion.Bundle.Monadic (
+  Bundle(..), Chunk(..),
+
+  -- * Size hints
+  size, sized,
+
+  -- * Length
+  length, null,
+
+  -- * Construction
+  empty, singleton, cons, snoc, replicate, replicateM, generate, generateM, (++),
+
+  -- * Accessing elements
+  head, last, (!!), (!?),
+
+  -- * Substreams
+  slice, init, tail, take, drop,
+
+  -- * Mapping
+  map, mapM, mapM_, trans, unbox, concatMap, flatten,
+
+  -- * Zipping
+  indexed, indexedR, zipWithM_,
+  zipWithM, zipWith3M, zipWith4M, zipWith5M, zipWith6M,
+  zipWith, zipWith3, zipWith4, zipWith5, zipWith6,
+  zip, zip3, zip4, zip5, zip6,
+
+  -- * Comparisons
+  eq, cmp,
+
+  -- * Filtering
+  filter, filterM, takeWhile, takeWhileM, dropWhile, dropWhileM,
+
+  -- * Searching
+  elem, notElem, find, findM, findIndex, findIndexM,
+
+  -- * Folding
+  foldl, foldlM, foldl1, foldl1M, foldM, fold1M,
+  foldl', foldlM', foldl1', foldl1M', foldM', fold1M',
+  foldr, foldrM, foldr1, foldr1M,
+
+  -- * Specialised folds
+  and, or, concatMapM,
+
+  -- * Unfolding
+  unfoldr, unfoldrM,
+  unfoldrN, unfoldrNM,
+  iterateN, iterateNM,
+
+  -- * Scans
+  prescanl, prescanlM, prescanl', prescanlM',
+  postscanl, postscanlM, postscanl', postscanlM',
+  scanl, scanlM, scanl', scanlM',
+  scanl1, scanl1M, scanl1', scanl1M',
+
+  -- * Enumerations
+  enumFromStepN, enumFromTo, enumFromThenTo,
+
+  -- * Conversions
+  toList, fromList, fromListN, unsafeFromList,
+  fromVector, reVector, fromVectors, concatVectors,
+  fromStream, chunks, elements
+) where
+
+import Data.Vector.Generic.Base
+import qualified Data.Vector.Generic.Mutable.Base as M
+import Data.Vector.Fusion.Bundle.Size
+import Data.Vector.Fusion.Util ( Box(..), delay_inline )
+import Data.Vector.Fusion.Stream.Monadic ( Stream(..), Step(..) )
+import qualified Data.Vector.Fusion.Stream.Monadic as S
+import Control.Monad.Primitive
+
+import qualified Data.List as List
+import Data.Char      ( ord )
+import GHC.Base       ( unsafeChr )
+import Control.Monad  ( liftM )
+import Prelude hiding ( length, null,
+                        replicate, (++),
+                        head, last, (!!),
+                        init, tail, take, drop,
+                        map, mapM, mapM_, concatMap,
+                        zipWith, zipWith3, zip, zip3,
+                        filter, takeWhile, dropWhile,
+                        elem, notElem,
+                        foldl, foldl1, foldr, foldr1,
+                        and, or,
+                        scanl, scanl1,
+                        enumFromTo, enumFromThenTo )
+
+import Data.Int  ( Int8, Int16, Int32, Int64 )
+import Data.Word ( Word8, Word16, Word32, Word, Word64 )
+
+#include "vector.h"
+#include "MachDeps.h"
+
+data Chunk v a = Chunk Int (forall m. (PrimMonad m, Vector v a) => Mutable v (PrimState m) a -> m ())
+
+-- | Monadic streams
+data Bundle m v a = Bundle { sElems  :: Stream m a
+                           , sChunks :: Stream m (Chunk v a)
+                           , sVector :: Maybe (v a)
+                           , sSize   :: Size
+                           }
+
+fromStream :: Monad m => Stream m a -> Size -> Bundle m v a
+{-# INLINE fromStream #-}
+fromStream (Stream step t) sz = Bundle (Stream step t) (Stream step' t) Nothing sz
+  where
+    step' s = do r <- step s
+                 return $ fmap (\x -> Chunk 1 (\v -> M.basicUnsafeWrite v 0 x)) r
+
+chunks :: Bundle m v a -> Stream m (Chunk v a)
+{-# INLINE chunks #-}
+chunks = sChunks
+
+elements :: Bundle m v a -> Stream m a
+{-# INLINE elements #-}
+elements = sElems
+
+-- | 'Size' hint of a 'Bundle'
+size :: Bundle m v a -> Size
+{-# INLINE size #-}
+size = sSize
+
+-- | Attach a 'Size' hint to a 'Bundle'
+sized :: Bundle m v a -> Size -> Bundle m v a
+{-# INLINE_FUSED sized #-}
+sized s sz = s { sSize = sz }
+
+-- Length
+-- ------
+
+-- | Length of a 'Bundle'
+length :: Monad m => Bundle m v a -> m Int
+{-# INLINE_FUSED length #-}
+length Bundle{sSize = Exact n}  = return n
+length Bundle{sChunks = s} = S.foldl' (\n (Chunk k _) -> n+k) 0 s
+
+-- | Check if a 'Bundle' is empty
+null :: Monad m => Bundle m v a -> m Bool
+{-# INLINE_FUSED null #-}
+null Bundle{sSize = Exact n} = return (n == 0)
+null Bundle{sChunks = s} = S.foldr (\(Chunk n _) z -> n == 0 && z) True s
+
+-- Construction
+-- ------------
+
+-- | Empty 'Bundle'
+empty :: Monad m => Bundle m v a
+{-# INLINE_FUSED empty #-}
+empty = fromStream S.empty (Exact 0)
+
+-- | Singleton 'Bundle'
+singleton :: Monad m => a -> Bundle m v a
+{-# INLINE_FUSED singleton #-}
+singleton x = fromStream (S.singleton x) (Exact 1)
+
+-- | Replicate a value to a given length
+replicate :: Monad m => Int -> a -> Bundle m v a
+{-# INLINE_FUSED replicate #-}
+replicate n x = Bundle (S.replicate n x)
+                       (S.singleton $ Chunk len (\v -> M.basicSet v x))
+                       Nothing
+                       (Exact len)
+  where
+    len = delay_inline max n 0
+
+-- | Yield a 'Bundle' of values obtained by performing the monadic action the
+-- given number of times
+replicateM :: Monad m => Int -> m a -> Bundle m v a
+{-# INLINE_FUSED replicateM #-}
+-- NOTE: We delay inlining max here because GHC will create a join point for
+-- the call to newArray# otherwise which is not really nice.
+replicateM n p = fromStream (S.replicateM n p) (Exact (delay_inline max n 0))
+
+generate :: Monad m => Int -> (Int -> a) -> Bundle m v a
+{-# INLINE generate #-}
+generate n f = generateM n (return . f)
+
+-- | Generate a stream from its indices
+generateM :: Monad m => Int -> (Int -> m a) -> Bundle m v a
+{-# INLINE_FUSED generateM #-}
+generateM n f = fromStream (S.generateM n f) (Exact (delay_inline max n 0))
+
+-- | Prepend an element
+cons :: Monad m => a -> Bundle m v a -> Bundle m v a
+{-# INLINE cons #-}
+cons x s = singleton x ++ s
+
+-- | Append an element
+snoc :: Monad m => Bundle m v a -> a -> Bundle m v a
+{-# INLINE snoc #-}
+snoc s x = s ++ singleton x
+
+infixr 5 ++
+-- | Concatenate two 'Bundle's
+(++) :: Monad m => Bundle m v a -> Bundle m v a -> Bundle m v a
+{-# INLINE_FUSED (++) #-}
+Bundle sa ta _ na ++ Bundle sb tb _ nb = Bundle (sa S.++ sb) (ta S.++ tb) Nothing (na + nb)
+
+-- Accessing elements
+-- ------------------
+
+-- | First element of the 'Bundle' or error if empty
+head :: Monad m => Bundle m v a -> m a
+{-# INLINE_FUSED head #-}
+head = S.head . sElems
+
+-- | Last element of the 'Bundle' or error if empty
+last :: Monad m => Bundle m v a -> m a
+{-# INLINE_FUSED last #-}
+last = S.last . sElems
+
+infixl 9 !!
+-- | Element at the given position
+(!!) :: Monad m => Bundle m v a -> Int -> m a
+{-# INLINE (!!) #-}
+b !! i = sElems b S.!! i
+
+infixl 9 !?
+-- | Element at the given position or 'Nothing' if out of bounds
+(!?) :: Monad m => Bundle m v a -> Int -> m (Maybe a)
+{-# INLINE (!?) #-}
+b !? i = sElems b S.!? i
+
+-- Substreams
+-- ----------
+
+-- | Extract a substream of the given length starting at the given position.
+slice :: Monad m => Int   -- ^ starting index
+                 -> Int   -- ^ length
+                 -> Bundle m v a
+                 -> Bundle m v a
+{-# INLINE slice #-}
+slice i n s = take n (drop i s)
+
+-- | All but the last element
+init :: Monad m => Bundle m v a -> Bundle m v a
+{-# INLINE_FUSED init #-}
+init Bundle{sElems = s, sSize = sz} = fromStream (S.init s) (sz-1)
+
+-- | All but the first element
+tail :: Monad m => Bundle m v a -> Bundle m v a
+{-# INLINE_FUSED tail #-}
+tail Bundle{sElems = s, sSize = sz} = fromStream (S.tail s) (sz-1)
+
+-- | The first @n@ elements
+take :: Monad m => Int -> Bundle m v a -> Bundle m v a
+{-# INLINE_FUSED take #-}
+take n Bundle{sElems = s, sSize = sz} = fromStream (S.take n s) (smaller (Exact n) sz)
+
+-- | All but the first @n@ elements
+drop :: Monad m => Int -> Bundle m v a -> Bundle m v a
+{-# INLINE_FUSED drop #-}
+drop n Bundle{sElems = s, sSize = sz} =
+  fromStream (S.drop n s) (clampedSubtract sz (Exact n))
+
+-- Mapping
+-- -------
+
+instance Monad m => Functor (Bundle m v) where
+  {-# INLINE fmap #-}
+  fmap = map
+
+-- | Map a function over a 'Bundle'
+map :: Monad m => (a -> b) -> Bundle m v a -> Bundle m v b
+{-# INLINE map #-}
+map f = mapM (return . f)
+
+-- | Map a monadic function over a 'Bundle'
+mapM :: Monad m => (a -> m b) -> Bundle m v a -> Bundle m v b
+{-# INLINE_FUSED mapM #-}
+mapM f Bundle{sElems = s, sSize = n} = fromStream (S.mapM f s) n
+
+-- | Execute a monadic action for each element of the 'Bundle'
+mapM_ :: Monad m => (a -> m b) -> Bundle m v a -> m ()
+{-# INLINE_FUSED mapM_ #-}
+mapM_ m = S.mapM_ m . sElems
+
+-- | Transform a 'Bundle' to use a different monad
+trans :: (Monad m, Monad m') => (forall z. m z -> m' z)
+                             -> Bundle m v a -> Bundle m' v a
+{-# INLINE_FUSED trans #-}
+trans f Bundle{sElems = s, sChunks = cs, sVector = v, sSize = n}
+  = Bundle { sElems = S.trans f s, sChunks = S.trans f cs, sVector = v, sSize = n }
+
+unbox :: Monad m => Bundle m v (Box a) -> Bundle m v a
+{-# INLINE_FUSED unbox #-}
+unbox Bundle{sElems = s, sSize = n} = fromStream (S.unbox s) n
+
+-- Zipping
+-- -------
+
+-- | Pair each element in a 'Bundle' with its index
+indexed :: Monad m => Bundle m v a -> Bundle m v (Int,a)
+{-# INLINE_FUSED indexed #-}
+indexed Bundle{sElems = s, sSize = n} = fromStream (S.indexed s) n
+
+-- | Pair each element in a 'Bundle' with its index, starting from the right
+-- and counting down
+indexedR :: Monad m => Int -> Bundle m v a -> Bundle m v (Int,a)
+{-# INLINE_FUSED indexedR #-}
+indexedR m Bundle{sElems = s, sSize = n} = fromStream (S.indexedR m s) n
+
+-- | Zip two 'Bundle's with the given monadic function
+zipWithM :: Monad m => (a -> b -> m c) -> Bundle m v a -> Bundle m v b -> Bundle m v c
+{-# INLINE_FUSED zipWithM #-}
+zipWithM f Bundle{sElems = sa, sSize = na}
+           Bundle{sElems = sb, sSize = nb} = fromStream (S.zipWithM f sa sb) (smaller na nb)
+
+-- FIXME: This might expose an opportunity for inplace execution.
+{-# RULES
+
+"zipWithM xs xs [Vector.Bundle]" forall f xs.
+  zipWithM f xs xs = mapM (\x -> f x x) xs   #-}
+
+
+zipWithM_ :: Monad m => (a -> b -> m c) -> Bundle m v a -> Bundle m v b -> m ()
+{-# INLINE zipWithM_ #-}
+zipWithM_ f sa sb = S.zipWithM_ f (sElems sa) (sElems sb)
+
+zipWith3M :: Monad m => (a -> b -> c -> m d) -> Bundle m v a -> Bundle m v b -> Bundle m v c -> Bundle m v d
+{-# INLINE_FUSED zipWith3M #-}
+zipWith3M f Bundle{sElems = sa, sSize = na}
+            Bundle{sElems = sb, sSize = nb}
+            Bundle{sElems = sc, sSize = nc}
+  = fromStream (S.zipWith3M f sa sb sc) (smaller na (smaller nb nc))
+
+zipWith4M :: Monad m => (a -> b -> c -> d -> m e)
+                     -> Bundle m v a -> Bundle m v b -> Bundle m v c -> Bundle m v d
+                     -> Bundle m v e
+{-# INLINE zipWith4M #-}
+zipWith4M f sa sb sc sd
+  = zipWithM (\(a,b) (c,d) -> f a b c d) (zip sa sb) (zip sc sd)
+
+zipWith5M :: Monad m => (a -> b -> c -> d -> e -> m f)
+                     -> Bundle m v a -> Bundle m v b -> Bundle m v c -> Bundle m v d
+                     -> Bundle m v e -> Bundle m v f
+{-# INLINE zipWith5M #-}
+zipWith5M f sa sb sc sd se
+  = zipWithM (\(a,b,c) (d,e) -> f a b c d e) (zip3 sa sb sc) (zip sd se)
+
+zipWith6M :: Monad m => (a -> b -> c -> d -> e -> f -> m g)
+                     -> Bundle m v a -> Bundle m v b -> Bundle m v c -> Bundle m v d
+                     -> Bundle m v e -> Bundle m v f -> Bundle m v g
+{-# INLINE zipWith6M #-}
+zipWith6M fn sa sb sc sd se sf
+  = zipWithM (\(a,b,c) (d,e,f) -> fn a b c d e f) (zip3 sa sb sc)
+                                                  (zip3 sd se sf)
+
+zipWith :: Monad m => (a -> b -> c) -> Bundle m v a -> Bundle m v b -> Bundle m v c
+{-# INLINE zipWith #-}
+zipWith f = zipWithM (\a b -> return (f a b))
+
+zipWith3 :: Monad m => (a -> b -> c -> d)
+                    -> Bundle m v a -> Bundle m v b -> Bundle m v c -> Bundle m v d
+{-# INLINE zipWith3 #-}
+zipWith3 f = zipWith3M (\a b c -> return (f a b c))
+
+zipWith4 :: Monad m => (a -> b -> c -> d -> e)
+                    -> Bundle m v a -> Bundle m v b -> Bundle m v c -> Bundle m v d
+                    -> Bundle m v e
+{-# INLINE zipWith4 #-}
+zipWith4 f = zipWith4M (\a b c d -> return (f a b c d))
+
+zipWith5 :: Monad m => (a -> b -> c -> d -> e -> f)
+                    -> Bundle m v a -> Bundle m v b -> Bundle m v c -> Bundle m v d
+                    -> Bundle m v e -> Bundle m v f
+{-# INLINE zipWith5 #-}
+zipWith5 f = zipWith5M (\a b c d e -> return (f a b c d e))
+
+zipWith6 :: Monad m => (a -> b -> c -> d -> e -> f -> g)
+                    -> Bundle m v a -> Bundle m v b -> Bundle m v c -> Bundle m v d
+                    -> Bundle m v e -> Bundle m v f -> Bundle m v g
+{-# INLINE zipWith6 #-}
+zipWith6 fn = zipWith6M (\a b c d e f -> return (fn a b c d e f))
+
+zip :: Monad m => Bundle m v a -> Bundle m v b -> Bundle m v (a,b)
+{-# INLINE zip #-}
+zip = zipWith (,)
+
+zip3 :: Monad m => Bundle m v a -> Bundle m v b -> Bundle m v c -> Bundle m v (a,b,c)
+{-# INLINE zip3 #-}
+zip3 = zipWith3 (,,)
+
+zip4 :: Monad m => Bundle m v a -> Bundle m v b -> Bundle m v c -> Bundle m v d
+                -> Bundle m v (a,b,c,d)
+{-# INLINE zip4 #-}
+zip4 = zipWith4 (,,,)
+
+zip5 :: Monad m => Bundle m v a -> Bundle m v b -> Bundle m v c -> Bundle m v d
+                -> Bundle m v e -> Bundle m v (a,b,c,d,e)
+{-# INLINE zip5 #-}
+zip5 = zipWith5 (,,,,)
+
+zip6 :: Monad m => Bundle m v a -> Bundle m v b -> Bundle m v c -> Bundle m v d
+                -> Bundle m v e -> Bundle m v f -> Bundle m v (a,b,c,d,e,f)
+{-# INLINE zip6 #-}
+zip6 = zipWith6 (,,,,,)
+
+-- Comparisons
+-- -----------
+
+-- | Check if two 'Bundle's are equal
+eq :: (Monad m, Eq a) => Bundle m v a -> Bundle m v a -> m Bool
+{-# INLINE_FUSED eq #-}
+eq x y = sElems x `S.eq` sElems y
+
+-- | Lexicographically compare two 'Bundle's
+cmp :: (Monad m, Ord a) => Bundle m v a -> Bundle m v a -> m Ordering
+{-# INLINE_FUSED cmp #-}
+cmp x y = sElems x `S.cmp` sElems y
+
+-- Filtering
+-- ---------
+
+-- | Drop elements which do not satisfy the predicate
+filter :: Monad m => (a -> Bool) -> Bundle m v a -> Bundle m v a
+{-# INLINE filter #-}
+filter f = filterM (return . f)
+
+-- | Drop elements which do not satisfy the monadic predicate
+filterM :: Monad m => (a -> m Bool) -> Bundle m v a -> Bundle m v a
+{-# INLINE_FUSED filterM #-}
+filterM f Bundle{sElems = s, sSize = n} = fromStream (S.filterM f s) (toMax n)
+
+-- | Longest prefix of elements that satisfy the predicate
+takeWhile :: Monad m => (a -> Bool) -> Bundle m v a -> Bundle m v a
+{-# INLINE takeWhile #-}
+takeWhile f = takeWhileM (return . f)
+
+-- | Longest prefix of elements that satisfy the monadic predicate
+takeWhileM :: Monad m => (a -> m Bool) -> Bundle m v a -> Bundle m v a
+{-# INLINE_FUSED takeWhileM #-}
+takeWhileM f Bundle{sElems = s, sSize = n} = fromStream (S.takeWhileM f s) (toMax n)
+
+-- | Drop the longest prefix of elements that satisfy the predicate
+dropWhile :: Monad m => (a -> Bool) -> Bundle m v a -> Bundle m v a
+{-# INLINE dropWhile #-}
+dropWhile f = dropWhileM (return . f)
+
+-- | Drop the longest prefix of elements that satisfy the monadic predicate
+dropWhileM :: Monad m => (a -> m Bool) -> Bundle m v a -> Bundle m v a
+{-# INLINE_FUSED dropWhileM #-}
+dropWhileM f Bundle{sElems = s, sSize = n} = fromStream (S.dropWhileM f s) (toMax n)
+
+-- Searching
+-- ---------
+
+infix 4 `elem`
+-- | Check whether the 'Bundle' contains an element
+elem :: (Monad m, Eq a) => a -> Bundle m v a -> m Bool
+{-# INLINE_FUSED elem #-}
+elem x = S.elem x . sElems
+
+infix 4 `notElem`
+-- | Inverse of `elem`
+notElem :: (Monad m, Eq a) => a -> Bundle m v a -> m Bool
+{-# INLINE notElem #-}
+notElem x = S.notElem x . sElems
+
+-- | Yield 'Just' the first element that satisfies the predicate or 'Nothing'
+-- if no such element exists.
+find :: Monad m => (a -> Bool) -> Bundle m v a -> m (Maybe a)
+{-# INLINE find #-}
+find f = findM (return . f)
+
+-- | Yield 'Just' the first element that satisfies the monadic predicate or
+-- 'Nothing' if no such element exists.
+findM :: Monad m => (a -> m Bool) -> Bundle m v a -> m (Maybe a)
+{-# INLINE_FUSED findM #-}
+findM f = S.findM f . sElems
+
+-- | Yield 'Just' the index of the first element that satisfies the predicate
+-- or 'Nothing' if no such element exists.
+findIndex :: Monad m => (a -> Bool) -> Bundle m v a -> m (Maybe Int)
+{-# INLINE_FUSED findIndex #-}
+findIndex f = findIndexM (return . f)
+
+-- | Yield 'Just' the index of the first element that satisfies the monadic
+-- predicate or 'Nothing' if no such element exists.
+findIndexM :: Monad m => (a -> m Bool) -> Bundle m v a -> m (Maybe Int)
+{-# INLINE_FUSED findIndexM #-}
+findIndexM f = S.findIndexM f . sElems
+
+-- Folding
+-- -------
+
+-- | Left fold
+foldl :: Monad m => (a -> b -> a) -> a -> Bundle m v b -> m a
+{-# INLINE foldl #-}
+foldl f = foldlM (\a b -> return (f a b))
+
+-- | Left fold with a monadic operator
+foldlM :: Monad m => (a -> b -> m a) -> a -> Bundle m v b -> m a
+{-# INLINE_FUSED foldlM #-}
+foldlM m z = S.foldlM m z . sElems
+
+-- | Same as 'foldlM'
+foldM :: Monad m => (a -> b -> m a) -> a -> Bundle m v b -> m a
+{-# INLINE foldM #-}
+foldM = foldlM
+
+-- | Left fold over a non-empty 'Bundle'
+foldl1 :: Monad m => (a -> a -> a) -> Bundle m v a -> m a
+{-# INLINE foldl1 #-}
+foldl1 f = foldl1M (\a b -> return (f a b))
+
+-- | Left fold over a non-empty 'Bundle' with a monadic operator
+foldl1M :: Monad m => (a -> a -> m a) -> Bundle m v a -> m a
+{-# INLINE_FUSED foldl1M #-}
+foldl1M f = S.foldl1M f . sElems
+
+-- | Same as 'foldl1M'
+fold1M :: Monad m => (a -> a -> m a) -> Bundle m v a -> m a
+{-# INLINE fold1M #-}
+fold1M = foldl1M
+
+-- | Left fold with a strict accumulator
+foldl' :: Monad m => (a -> b -> a) -> a -> Bundle m v b -> m a
+{-# INLINE foldl' #-}
+foldl' f = foldlM' (\a b -> return (f a b))
+
+-- | Left fold with a strict accumulator and a monadic operator
+foldlM' :: Monad m => (a -> b -> m a) -> a -> Bundle m v b -> m a
+{-# INLINE_FUSED foldlM' #-}
+foldlM' m z = S.foldlM' m z . sElems
+
+-- | Same as 'foldlM''
+foldM' :: Monad m => (a -> b -> m a) -> a -> Bundle m v b -> m a
+{-# INLINE foldM' #-}
+foldM' = foldlM'
+
+-- | Left fold over a non-empty 'Bundle' with a strict accumulator
+foldl1' :: Monad m => (a -> a -> a) -> Bundle m v a -> m a
+{-# INLINE foldl1' #-}
+foldl1' f = foldl1M' (\a b -> return (f a b))
+
+-- | Left fold over a non-empty 'Bundle' with a strict accumulator and a
+-- monadic operator
+foldl1M' :: Monad m => (a -> a -> m a) -> Bundle m v a -> m a
+{-# INLINE_FUSED foldl1M' #-}
+foldl1M' f = S.foldl1M' f . sElems
+
+-- | Same as 'foldl1M''
+fold1M' :: Monad m => (a -> a -> m a) -> Bundle m v a -> m a
+{-# INLINE fold1M' #-}
+fold1M' = foldl1M'
+
+-- | Right fold
+foldr :: Monad m => (a -> b -> b) -> b -> Bundle m v a -> m b
+{-# INLINE foldr #-}
+foldr f = foldrM (\a b -> return (f a b))
+
+-- | Right fold with a monadic operator
+foldrM :: Monad m => (a -> b -> m b) -> b -> Bundle m v a -> m b
+{-# INLINE_FUSED foldrM #-}
+foldrM f z = S.foldrM f z . sElems
+
+-- | Right fold over a non-empty stream
+foldr1 :: Monad m => (a -> a -> a) -> Bundle m v a -> m a
+{-# INLINE foldr1 #-}
+foldr1 f = foldr1M (\a b -> return (f a b))
+
+-- | Right fold over a non-empty stream with a monadic operator
+foldr1M :: Monad m => (a -> a -> m a) -> Bundle m v a -> m a
+{-# INLINE_FUSED foldr1M #-}
+foldr1M f = S.foldr1M f . sElems
+
+-- Specialised folds
+-- -----------------
+
+and :: Monad m => Bundle m v Bool -> m Bool
+{-# INLINE_FUSED and #-}
+and = S.and . sElems
+
+or :: Monad m => Bundle m v Bool -> m Bool
+{-# INLINE_FUSED or #-}
+or = S.or . sElems
+
+concatMap :: Monad m => (a -> Bundle m v b) -> Bundle m v a -> Bundle m v b
+{-# INLINE concatMap #-}
+concatMap f = concatMapM (return . f)
+
+concatMapM :: Monad m => (a -> m (Bundle m v b)) -> Bundle m v a -> Bundle m v b
+{-# INLINE_FUSED concatMapM #-}
+concatMapM f Bundle{sElems = s} = fromStream (S.concatMapM (liftM sElems . f) s) Unknown
+
+-- | Create a 'Bundle' of values from a 'Bundle' of streamable things
+flatten :: Monad m => (a -> m s) -> (s -> m (Step s b)) -> Size
+                   -> Bundle m v a -> Bundle m v b
+{-# INLINE_FUSED flatten #-}
+flatten mk istep sz Bundle{sElems = s} = fromStream (S.flatten mk istep s) sz
+
+-- Unfolding
+-- ---------
+
+-- | Unfold
+unfoldr :: Monad m => (s -> Maybe (a, s)) -> s -> Bundle m u a
+{-# INLINE_FUSED unfoldr #-}
+unfoldr f = unfoldrM (return . f)
+
+-- | Unfold with a monadic function
+unfoldrM :: Monad m => (s -> m (Maybe (a, s))) -> s -> Bundle m u a
+{-# INLINE_FUSED unfoldrM #-}
+unfoldrM f s = fromStream (S.unfoldrM f s) Unknown
+
+-- | Unfold at most @n@ elements
+unfoldrN :: Monad m => Int -> (s -> Maybe (a, s)) -> s -> Bundle m u a
+{-# INLINE_FUSED unfoldrN #-}
+unfoldrN n f = unfoldrNM n (return . f)
+
+-- | Unfold at most @n@ elements with a monadic functions
+unfoldrNM :: Monad m => Int -> (s -> m (Maybe (a, s))) -> s -> Bundle m u a
+{-# INLINE_FUSED unfoldrNM #-}
+unfoldrNM n f s = fromStream (S.unfoldrNM n f s) (Max (delay_inline max n 0))
+
+-- | Apply monadic function n times to value. Zeroth element is original value.
+iterateNM :: Monad m => Int -> (a -> m a) -> a -> Bundle m u a
+{-# INLINE_FUSED iterateNM #-}
+iterateNM n f x0 = fromStream (S.iterateNM n f x0) (Exact (delay_inline max n 0))
+
+-- | Apply function n times to value. Zeroth element is original value.
+iterateN :: Monad m => Int -> (a -> a) -> a -> Bundle m u a
+{-# INLINE_FUSED iterateN #-}
+iterateN n f x0 = iterateNM n (return . f) x0
+
+-- Scans
+-- -----
+
+-- | Prefix scan
+prescanl :: Monad m => (a -> b -> a) -> a -> Bundle m v b -> Bundle m v a
+{-# INLINE prescanl #-}
+prescanl f = prescanlM (\a b -> return (f a b))
+
+-- | Prefix scan with a monadic operator
+prescanlM :: Monad m => (a -> b -> m a) -> a -> Bundle m v b -> Bundle m v a
+{-# INLINE_FUSED prescanlM #-}
+prescanlM f z Bundle{sElems = s, sSize = sz} = fromStream (S.prescanlM f z s) sz
+
+-- | Prefix scan with strict accumulator
+prescanl' :: Monad m => (a -> b -> a) -> a -> Bundle m v b -> Bundle m v a
+{-# INLINE prescanl' #-}
+prescanl' f = prescanlM' (\a b -> return (f a b))
+
+-- | Prefix scan with strict accumulator and a monadic operator
+prescanlM' :: Monad m => (a -> b -> m a) -> a -> Bundle m v b -> Bundle m v a
+{-# INLINE_FUSED prescanlM' #-}
+prescanlM' f z Bundle{sElems = s, sSize = sz} = fromStream (S.prescanlM' f z s) sz
+
+-- | Suffix scan
+postscanl :: Monad m => (a -> b -> a) -> a -> Bundle m v b -> Bundle m v a
+{-# INLINE postscanl #-}
+postscanl f = postscanlM (\a b -> return (f a b))
+
+-- | Suffix scan with a monadic operator
+postscanlM :: Monad m => (a -> b -> m a) -> a -> Bundle m v b -> Bundle m v a
+{-# INLINE_FUSED postscanlM #-}
+postscanlM f z Bundle{sElems = s, sSize = sz} = fromStream (S.postscanlM f z s) sz
+
+-- | Suffix scan with strict accumulator
+postscanl' :: Monad m => (a -> b -> a) -> a -> Bundle m v b -> Bundle m v a
+{-# INLINE postscanl' #-}
+postscanl' f = postscanlM' (\a b -> return (f a b))
+
+-- | Suffix scan with strict acccumulator and a monadic operator
+postscanlM' :: Monad m => (a -> b -> m a) -> a -> Bundle m v b -> Bundle m v a
+{-# INLINE_FUSED postscanlM' #-}
+postscanlM' f z Bundle{sElems = s, sSize = sz} = fromStream (S.postscanlM' f z s) sz
+
+-- | Haskell-style scan
+scanl :: Monad m => (a -> b -> a) -> a -> Bundle m v b -> Bundle m v a
+{-# INLINE scanl #-}
+scanl f = scanlM (\a b -> return (f a b))
+
+-- | Haskell-style scan with a monadic operator
+scanlM :: Monad m => (a -> b -> m a) -> a -> Bundle m v b -> Bundle m v a
+{-# INLINE scanlM #-}
+scanlM f z s = z `cons` postscanlM f z s
+
+-- | Haskell-style scan with strict accumulator
+scanl' :: Monad m => (a -> b -> a) -> a -> Bundle m v b -> Bundle m v a
+{-# INLINE scanl' #-}
+scanl' f = scanlM' (\a b -> return (f a b))
+
+-- | Haskell-style scan with strict accumulator and a monadic operator
+scanlM' :: Monad m => (a -> b -> m a) -> a -> Bundle m v b -> Bundle m v a
+{-# INLINE scanlM' #-}
+scanlM' f z s = z `seq` (z `cons` postscanlM f z s)
+
+-- | Scan over a non-empty 'Bundle'
+scanl1 :: Monad m => (a -> a -> a) -> Bundle m v a -> Bundle m v a
+{-# INLINE scanl1 #-}
+scanl1 f = scanl1M (\x y -> return (f x y))
+
+-- | Scan over a non-empty 'Bundle' with a monadic operator
+scanl1M :: Monad m => (a -> a -> m a) -> Bundle m v a -> Bundle m v a
+{-# INLINE_FUSED scanl1M #-}
+scanl1M f Bundle{sElems = s, sSize = sz} = fromStream (S.scanl1M f s) sz
+
+-- | Scan over a non-empty 'Bundle' with a strict accumulator
+scanl1' :: Monad m => (a -> a -> a) -> Bundle m v a -> Bundle m v a
+{-# INLINE scanl1' #-}
+scanl1' f = scanl1M' (\x y -> return (f x y))
+
+-- | Scan over a non-empty 'Bundle' with a strict accumulator and a monadic
+-- operator
+scanl1M' :: Monad m => (a -> a -> m a) -> Bundle m v a -> Bundle m v a
+{-# INLINE_FUSED scanl1M' #-}
+scanl1M' f Bundle{sElems = s, sSize = sz} = fromStream (S.scanl1M' f s) sz
+
+-- Enumerations
+-- ------------
+
+-- The Enum class is broken for this, there just doesn't seem to be a
+-- way to implement this generically. We have to specialise for as many types
+-- as we can but this doesn't help in polymorphic loops.
+
+-- | Yield a 'Bundle' of the given length containing the values @x@, @x+y@,
+-- @x+y+y@ etc.
+enumFromStepN :: (Num a, Monad m) => a -> a -> Int -> Bundle m v a
+{-# INLINE_FUSED enumFromStepN #-}
+enumFromStepN x y n = fromStream (S.enumFromStepN x y n) (Exact (delay_inline max n 0))
+
+-- | Enumerate values
+--
+-- /WARNING:/ This operation can be very inefficient. If at all possible, use
+-- 'enumFromStepN' instead.
+enumFromTo :: (Enum a, Monad m) => a -> a -> Bundle m v a
+{-# INLINE_FUSED enumFromTo #-}
+enumFromTo x y = fromList [x .. y]
+
+-- NOTE: We use (x+1) instead of (succ x) below because the latter checks for
+-- overflow which can't happen here.
+
+-- FIXME: add "too large" test for Int
+enumFromTo_small :: (Integral a, Monad m) => a -> a -> Bundle m v a
+{-# INLINE_FUSED enumFromTo_small #-}
+enumFromTo_small x y = x `seq` y `seq` fromStream (Stream step x) (Exact n)
+  where
+    n = delay_inline max (fromIntegral y - fromIntegral x + 1) 0
+
+    {-# INLINE_INNER step #-}
+    step z | z <= y    = return $ Yield z (z+1)
+           | otherwise = return $ Done
+
+{-# RULES
+
+"enumFromTo<Int8> [Bundle]"
+  enumFromTo = enumFromTo_small :: Monad m => Int8 -> Int8 -> Bundle m v Int8
+
+"enumFromTo<Int16> [Bundle]"
+  enumFromTo = enumFromTo_small :: Monad m => Int16 -> Int16 -> Bundle m v Int16
+
+"enumFromTo<Word8> [Bundle]"
+  enumFromTo = enumFromTo_small :: Monad m => Word8 -> Word8 -> Bundle m v Word8
+
+"enumFromTo<Word16> [Bundle]"
+  enumFromTo = enumFromTo_small :: Monad m => Word16 -> Word16 -> Bundle m v Word16   #-}
+
+
+
+#if WORD_SIZE_IN_BITS > 32
+
+{-# RULES
+
+"enumFromTo<Int32> [Bundle]"
+  enumFromTo = enumFromTo_small :: Monad m => Int32 -> Int32 -> Bundle m v Int32
+
+"enumFromTo<Word32> [Bundle]"
+  enumFromTo = enumFromTo_small :: Monad m => Word32 -> Word32 -> Bundle m v Word32   #-}
+
+#endif
+
+-- NOTE: We could implement a generic "too large" test:
+--
+-- len x y | x > y = 0
+--         | n > 0 && n <= fromIntegral (maxBound :: Int) = fromIntegral n
+--         | otherwise = error
+--   where
+--     n = y-x+1
+--
+-- Alas, GHC won't eliminate unnecessary comparisons (such as n >= 0 for
+-- unsigned types). See http://hackage.haskell.org/trac/ghc/ticket/3744
+--
+
+enumFromTo_int :: forall m v. Monad m => Int -> Int -> Bundle m v Int
+{-# INLINE_FUSED enumFromTo_int #-}
+enumFromTo_int x y = x `seq` y `seq` fromStream (Stream step x) (Exact (len x y))
+  where
+    {-# INLINE [0] len #-}
+    len :: Int -> Int -> Int
+    len u v | u > v     = 0
+            | otherwise = BOUNDS_CHECK(check) "enumFromTo" "vector too large"
+                          (n > 0)
+                        $ n
+      where
+        n = v-u+1
+
+    {-# INLINE_INNER step #-}
+    step z | z <= y    = return $ Yield z (z+1)
+           | otherwise = return $ Done
+
+enumFromTo_intlike :: (Integral a, Monad m) => a -> a -> Bundle m v a
+{-# INLINE_FUSED enumFromTo_intlike #-}
+enumFromTo_intlike x y = x `seq` y `seq` fromStream (Stream step x) (Exact (len x y))
+  where
+    {-# INLINE [0] len #-}
+    len u v | u > v     = 0
+            | otherwise = BOUNDS_CHECK(check) "enumFromTo" "vector too large"
+                          (n > 0)
+                        $ fromIntegral n
+      where
+        n = v-u+1
+
+    {-# INLINE_INNER step #-}
+    step z | z <= y    = return $ Yield z (z+1)
+           | otherwise = return $ Done
+
+{-# RULES
+
+"enumFromTo<Int> [Bundle]"
+  enumFromTo = enumFromTo_int :: Monad m => Int -> Int -> Bundle m v Int
+
+#if WORD_SIZE_IN_BITS > 32
+
+"enumFromTo<Int64> [Bundle]"
+  enumFromTo = enumFromTo_intlike :: Monad m => Int64 -> Int64 -> Bundle m v Int64    #-}
+
+#else
+
+"enumFromTo<Int32> [Bundle]"
+  enumFromTo = enumFromTo_intlike :: Monad m => Int32 -> Int32 -> Bundle m v Int32    #-}
+
+#endif
+
+
+
+enumFromTo_big_word :: (Integral a, Monad m) => a -> a -> Bundle m v a
+{-# INLINE_FUSED enumFromTo_big_word #-}
+enumFromTo_big_word x y = x `seq` y `seq` fromStream (Stream step x) (Exact (len x y))
+  where
+    {-# INLINE [0] len #-}
+    len u v | u > v     = 0
+            | otherwise = BOUNDS_CHECK(check) "enumFromTo" "vector too large"
+                          (n < fromIntegral (maxBound :: Int))
+                        $ fromIntegral (n+1)
+      where
+        n = v-u
+
+    {-# INLINE_INNER step #-}
+    step z | z <= y    = return $ Yield z (z+1)
+           | otherwise = return $ Done
+
+{-# RULES
+
+"enumFromTo<Word> [Bundle]"
+  enumFromTo = enumFromTo_big_word :: Monad m => Word -> Word -> Bundle m v Word
+
+"enumFromTo<Word64> [Bundle]"
+  enumFromTo = enumFromTo_big_word
+                        :: Monad m => Word64 -> Word64 -> Bundle m v Word64
+
+#if WORD_SIZE_IN_BITS == 32
+
+"enumFromTo<Word32> [Bundle]"
+  enumFromTo = enumFromTo_big_word
+                        :: Monad m => Word32 -> Word32 -> Bundle m v Word32
+
+#endif
+
+"enumFromTo<Integer> [Bundle]"
+  enumFromTo = enumFromTo_big_word
+                        :: Monad m => Integer -> Integer -> Bundle m v Integer   #-}
+
+
+
+-- FIXME: the "too large" test is totally wrong
+enumFromTo_big_int :: (Integral a, Monad m) => a -> a -> Bundle m v a
+{-# INLINE_FUSED enumFromTo_big_int #-}
+enumFromTo_big_int x y = x `seq` y `seq` fromStream (Stream step x) (Exact (len x y))
+  where
+    {-# INLINE [0] len #-}
+    len u v | u > v     = 0
+            | otherwise = BOUNDS_CHECK(check) "enumFromTo" "vector too large"
+                          (n > 0 && n <= fromIntegral (maxBound :: Int))
+                        $ fromIntegral n
+      where
+        n = v-u+1
+
+    {-# INLINE_INNER step #-}
+    step z | z <= y    = return $ Yield z (z+1)
+           | otherwise = return $ Done
+
+#if WORD_SIZE_IN_BITS > 32
+
+{-# RULES
+
+"enumFromTo<Int64> [Bundle]"
+  enumFromTo = enumFromTo_big_int :: Monad m => Int64 -> Int64 -> Bundle m v Int64   #-}
+
+
+
+#endif
+
+enumFromTo_char :: Monad m => Char -> Char -> Bundle m v Char
+{-# INLINE_FUSED enumFromTo_char #-}
+enumFromTo_char x y = x `seq` y `seq` fromStream (Stream step xn) (Exact n)
+  where
+    xn = ord x
+    yn = ord y
+
+    n = delay_inline max 0 (yn - xn + 1)
+
+    {-# INLINE_INNER step #-}
+    step zn | zn <= yn  = return $ Yield (unsafeChr zn) (zn+1)
+            | otherwise = return $ Done
+
+{-# RULES
+
+"enumFromTo<Char> [Bundle]"
+  enumFromTo = enumFromTo_char   #-}
+
+
+
+------------------------------------------------------------------------
+
+-- Specialise enumFromTo for Float and Double.
+-- Also, try to do something about pairs?
+
+enumFromTo_double :: (Monad m, Ord a, RealFrac a) => a -> a -> Bundle m v a
+{-# INLINE_FUSED enumFromTo_double #-}
+enumFromTo_double n m = n `seq` m `seq` fromStream (Stream step n) (Max (len n lim))
+  where
+    lim = m + 1/2 -- important to float out
+
+    {-# INLINE [0] len #-}
+    len x y | x > y     = 0
+            | otherwise = BOUNDS_CHECK(check) "enumFromTo" "vector too large"
+                          (l > 0)
+                        $ fromIntegral l
+      where
+        l :: Integer
+        l = truncate (y-x)+2
+
+    {-# INLINE_INNER step #-}
+    step x | x <= lim  = return $ Yield x (x+1)
+           | otherwise = return $ Done
+
+{-# RULES
+
+"enumFromTo<Double> [Bundle]"
+  enumFromTo = enumFromTo_double :: Monad m => Double -> Double -> Bundle m v Double
+
+"enumFromTo<Float> [Bundle]"
+  enumFromTo = enumFromTo_double :: Monad m => Float -> Float -> Bundle m v Float   #-}
+
+
+
+------------------------------------------------------------------------
+
+-- | Enumerate values with a given step.
+--
+-- /WARNING:/ This operation is very inefficient. If at all possible, use
+-- 'enumFromStepN' instead.
+enumFromThenTo :: (Enum a, Monad m) => a -> a -> a -> Bundle m v a
+{-# INLINE_FUSED enumFromThenTo #-}
+enumFromThenTo x y z = fromList [x, y .. z]
+
+-- FIXME: Specialise enumFromThenTo.
+
+-- Conversions
+-- -----------
+
+-- | Convert a 'Bundle' to a list
+toList :: Monad m => Bundle m v a -> m [a]
+{-# INLINE toList #-}
+toList = foldr (:) []
+
+-- | Convert a list to a 'Bundle'
+fromList :: Monad m => [a] -> Bundle m v a
+{-# INLINE fromList #-}
+fromList xs = unsafeFromList Unknown xs
+
+-- | Convert the first @n@ elements of a list to a 'Bundle'
+fromListN :: Monad m => Int -> [a] -> Bundle m v a
+{-# INLINE_FUSED fromListN #-}
+fromListN n xs = fromStream (S.fromListN n xs) (Max (delay_inline max n 0))
+
+-- | Convert a list to a 'Bundle' with the given 'Size' hint.
+unsafeFromList :: Monad m => Size -> [a] -> Bundle m v a
+{-# INLINE_FUSED unsafeFromList #-}
+unsafeFromList sz xs = fromStream (S.fromList xs) sz
+
+fromVector :: (Monad m, Vector v a) => v a -> Bundle m v a
+{-# INLINE_FUSED fromVector #-}
+fromVector v = v `seq` n `seq` Bundle (Stream step 0)
+                                      (Stream vstep True)
+                                      (Just v)
+                                      (Exact n)
+  where
+    n = basicLength v
+
+    {-# INLINE step #-}
+    step i | i >= n = return Done
+           | otherwise = case basicUnsafeIndexM v i of
+                           Box x -> return $ Yield x (i+1)
+
+
+    {-# INLINE vstep #-}
+    vstep True  = return (Yield (Chunk (basicLength v) (\mv -> basicUnsafeCopy mv v)) False)
+    vstep False = return Done
+
+fromVectors :: forall m v a. (Monad m, Vector v a) => [v a] -> Bundle m v a
+{-# INLINE_FUSED fromVectors #-}
+fromVectors us = Bundle (Stream pstep (Left us))
+                        (Stream vstep us)
+                        Nothing
+                        (Exact n)
+  where
+    n = List.foldl' (\k v -> k + basicLength v) 0 us
+
+    pstep (Left []) = return Done
+    pstep (Left (v:vs)) = basicLength v `seq` return (Skip (Right (v,0,vs)))
+
+    pstep (Right (v,i,vs))
+      | i >= basicLength v = return $ Skip (Left vs)
+      | otherwise          = case basicUnsafeIndexM v i of
+                               Box x -> return $ Yield x (Right (v,i+1,vs))
+
+    -- FIXME: work around bug in GHC 7.6.1
+    vstep :: [v a] -> m (Step [v a] (Chunk v a))
+    vstep [] = return Done
+    vstep (v:vs) = return $ Yield (Chunk (basicLength v)
+                                         (\mv -> INTERNAL_CHECK(check) "concatVectors" "length mismatch"
+                                                                       (M.basicLength mv == basicLength v)
+                                                 $ basicUnsafeCopy mv v)) vs
+
+
+concatVectors :: (Monad m, Vector v a) => Bundle m u (v a) -> Bundle m v a
+{-# INLINE_FUSED concatVectors #-}
+concatVectors Bundle{sElems = Stream step t}
+  = Bundle (Stream pstep (Left t))
+           (Stream vstep t)
+           Nothing
+           Unknown
+  where
+    pstep (Left s) = do
+      r <- step s
+      case r of
+        Yield v s' -> basicLength v `seq` return (Skip (Right (v,0,s')))
+        Skip    s' -> return (Skip (Left s'))
+        Done       -> return Done
+
+    pstep (Right (v,i,s))
+      | i >= basicLength v = return (Skip (Left s))
+      | otherwise          = case basicUnsafeIndexM v i of
+                               Box x -> return (Yield x (Right (v,i+1,s)))
+
+
+    vstep s = do
+      r <- step s
+      case r of
+        Yield v s' -> return (Yield (Chunk (basicLength v)
+                                           (\mv -> INTERNAL_CHECK(check) "concatVectors" "length mismatch"
+                                                                          (M.basicLength mv == basicLength v)
+                                                   $ basicUnsafeCopy mv v)) s')
+        Skip    s' -> return (Skip s')
+        Done       -> return Done
+
+reVector :: Monad m => Bundle m u a -> Bundle m v a
+{-# INLINE_FUSED reVector #-}
+reVector Bundle{sElems = s, sSize = n} = fromStream s n
+
+{-# RULES
+
+"reVector [Vector]"
+  reVector = id
+
+"reVector/reVector [Vector]" forall s.
+  reVector (reVector s) = s   #-}
+
+
+
diff --git a/Data/Vector/Fusion/Bundle/Size.hs b/Data/Vector/Fusion/Bundle/Size.hs
new file mode 100644
--- /dev/null
+++ b/Data/Vector/Fusion/Bundle/Size.hs
@@ -0,0 +1,121 @@
+-- |
+-- Module      : Data.Vector.Fusion.Bundle.Size
+-- Copyright   : (c) Roman Leshchinskiy 2008-2010
+-- License     : BSD-style
+--
+-- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
+-- Stability   : experimental
+-- Portability : portable
+--
+-- Size hints for streams.
+--
+
+module Data.Vector.Fusion.Bundle.Size (
+  Size(..), clampedSubtract, smaller, larger, toMax, upperBound, lowerBound
+) where
+
+import Data.Vector.Fusion.Util ( delay_inline )
+
+-- | Size hint
+data Size = Exact Int          -- ^ Exact size
+          | Max   Int          -- ^ Upper bound on the size
+          | Unknown            -- ^ Unknown size
+        deriving( Eq, Show )
+
+instance Num Size where
+  Exact m + Exact n = checkedAdd Exact m n
+  Exact m + Max   n = checkedAdd Max m n
+
+  Max   m + Exact n = checkedAdd Max m n
+  Max   m + Max   n = checkedAdd Max m n
+
+  _       + _       = Unknown
+
+
+  Exact m - Exact n = checkedSubtract Exact m n
+  Exact m - Max   _ = Max   m
+
+  Max   m - Exact n = checkedSubtract Max m n
+  Max   m - Max   _ = Max   m
+  Max   m - Unknown = Max   m
+
+  _       - _       = Unknown
+
+
+  fromInteger n     = Exact (fromInteger n)
+
+  (*)    = error "vector: internal error * for Bundle.size isn't defined"
+  abs    = error "vector: internal error abs for Bundle.size isn't defined"
+  signum = error "vector: internal error signum for Bundle.size isn't defined"
+
+{-# INLINE checkedAdd #-}
+checkedAdd :: (Int -> Size) -> Int -> Int -> Size
+checkedAdd con m n
+    -- Note: we assume m and n are >= 0.
+  | r < m || r < n =
+      error $ "Data.Vector.Fusion.Bundle.Size.checkedAdd: overflow: " ++ show r
+  | otherwise = con r
+  where
+    r = m + n
+
+{-# INLINE checkedSubtract #-}
+checkedSubtract :: (Int -> Size) -> Int -> Int -> Size
+checkedSubtract con m n
+  | r < 0 =
+      error $ "Data.Vector.Fusion.Bundle.Size.checkedSubtract: underflow: " ++ show r
+  | otherwise = con r
+  where
+    r = m - n
+
+-- | Subtract two sizes with clamping to 0, for drop-like things
+{-# INLINE clampedSubtract #-}
+clampedSubtract :: Size -> Size -> Size
+clampedSubtract (Exact m) (Exact n) = Exact (max 0 (m - n))
+clampedSubtract (Max   m) (Exact n)
+  | m <= n = Exact 0
+  | otherwise = Max (m - n)
+clampedSubtract (Exact m) (Max   _) = Max m
+clampedSubtract (Max   m) (Max   _) = Max m
+clampedSubtract _         _ = Unknown
+
+-- | Minimum of two size hints
+smaller :: Size -> Size -> Size
+{-# INLINE smaller #-}
+smaller (Exact m) (Exact n) = Exact (delay_inline min m n)
+smaller (Exact m) (Max   n) = Max   (delay_inline min m n)
+smaller (Exact m) Unknown   = Max   m
+smaller (Max   m) (Exact n) = Max   (delay_inline min m n)
+smaller (Max   m) (Max   n) = Max   (delay_inline min m n)
+smaller (Max   m) Unknown   = Max   m
+smaller Unknown   (Exact n) = Max   n
+smaller Unknown   (Max   n) = Max   n
+smaller Unknown   Unknown   = Unknown
+
+-- | Maximum of two size hints
+larger :: Size -> Size -> Size
+{-# INLINE larger #-}
+larger (Exact m) (Exact n)             = Exact (delay_inline max m n)
+larger (Exact m) (Max   n) | m >= n    = Exact m
+                           | otherwise = Max   n
+larger (Max   m) (Exact n) | n >= m    = Exact n
+                           | otherwise = Max   m
+larger (Max   m) (Max   n)             = Max   (delay_inline max m n)
+larger _         _                     = Unknown
+
+-- | Convert a size hint to an upper bound
+toMax :: Size -> Size
+toMax (Exact n) = Max n
+toMax (Max   n) = Max n
+toMax Unknown   = Unknown
+
+-- | Compute the minimum size from a size hint
+lowerBound :: Size -> Int
+lowerBound (Exact n) = n
+lowerBound _         = 0
+
+-- | Compute the maximum size from a size hint if possible
+upperBound :: Size -> Maybe Int
+upperBound (Exact n) = Just n
+upperBound (Max   n) = Just n
+upperBound Unknown   = Nothing
+
diff --git a/Data/Vector/Fusion/Stream.hs b/Data/Vector/Fusion/Stream.hs
deleted file mode 100644
--- a/Data/Vector/Fusion/Stream.hs
+++ /dev/null
@@ -1,634 +0,0 @@
-{-# LANGUAGE FlexibleInstances, Rank2Types, BangPatterns #-}
-
--- |
--- Module      : Data.Vector.Fusion.Stream
--- Copyright   : (c) Roman Leshchinskiy 2008-2010
--- License     : BSD-style
---
--- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
--- Stability   : experimental
--- Portability : non-portable
--- 
--- Streams for stream fusion
---
-
-module Data.Vector.Fusion.Stream (
-  -- * Types
-  Step(..), Stream, MStream,
-
-  -- * In-place markers
-  inplace,
-
-  -- * Size hints
-  size, sized,
-
-  -- * Length information
-  length, null,
-
-  -- * Construction
-  empty, singleton, cons, snoc, replicate, generate, (++),
-
-  -- * Accessing individual elements
-  head, last, (!!), (!?),
-
-  -- * Substreams
-  slice, init, tail, take, drop,
-
-  -- * Mapping
-  map, concatMap, flatten, unbox,
-  
-  -- * Zipping
-  indexed, indexedR,
-  zipWith, zipWith3, zipWith4, zipWith5, zipWith6,
-  zip, zip3, zip4, zip5, zip6,
-
-  -- * Filtering
-  filter, takeWhile, dropWhile,
-
-  -- * Searching
-  elem, notElem, find, findIndex,
-
-  -- * Folding
-  foldl, foldl1, foldl', foldl1', foldr, foldr1,
-
-  -- * Specialised folds
-  and, or,
-
-  -- * Unfolding
-  unfoldr, unfoldrN, iterateN,
-
-  -- * Scans
-  prescanl, prescanl',
-  postscanl, postscanl',
-  scanl, scanl',
-  scanl1, scanl1',
-
-  -- * Enumerations
-  enumFromStepN, enumFromTo, enumFromThenTo,
-
-  -- * Conversions
-  toList, fromList, fromListN, unsafeFromList, liftStream,
-
-  -- * Monadic combinators
-  mapM, mapM_, zipWithM, zipWithM_, filterM, foldM, fold1M, foldM', fold1M',
-
-  eq, cmp
-) where
-
-import Data.Vector.Fusion.Stream.Size
-import Data.Vector.Fusion.Util
-import Data.Vector.Fusion.Stream.Monadic ( Step(..), SPEC(..) )
-import qualified Data.Vector.Fusion.Stream.Monadic as M
-
-import Prelude hiding ( length, null,
-                        replicate, (++),
-                        head, last, (!!),
-                        init, tail, take, drop,
-                        map, concatMap,
-                        zipWith, zipWith3, zip, zip3,
-                        filter, takeWhile, dropWhile,
-                        elem, notElem,
-                        foldl, foldl1, foldr, foldr1,
-                        and, or,
-                        scanl, scanl1,
-                        enumFromTo, enumFromThenTo,
-                        mapM, mapM_ )
-
-import GHC.Base ( build )
-
-#include "vector.h"
-
--- | The type of pure streams 
-type Stream = M.Stream Id
-
--- | Alternative name for monadic streams
-type MStream = M.Stream
-
-inplace :: (forall m. Monad m => M.Stream m a -> M.Stream m b)
-        -> Stream a -> Stream b
-{-# INLINE_STREAM inplace #-}
-inplace f s = s `seq` f s
-
-{-# RULES
-
-"inplace/inplace [Vector]"
-  forall (f :: forall m. Monad m => MStream m a -> MStream m a)
-         (g :: forall m. Monad m => MStream m a -> MStream m a)
-         s.
-  inplace f (inplace g s) = inplace (f . g) s
-
-  #-}
-
--- | Convert a pure stream to a monadic stream
-liftStream :: Monad m => Stream a -> M.Stream m a
-{-# INLINE_STREAM liftStream #-}
-liftStream (M.Stream step s sz) = M.Stream (return . unId . step) s sz
-
--- | 'Size' hint of a 'Stream'
-size :: Stream a -> Size
-{-# INLINE size #-}
-size = M.size
-
--- | Attach a 'Size' hint to a 'Stream'
-sized :: Stream a -> Size -> Stream a
-{-# INLINE sized #-}
-sized = M.sized
-
--- Length
--- ------
-
--- | Length of a 'Stream'
-length :: Stream a -> Int
-{-# INLINE length #-}
-length = unId . M.length
-
--- | Check if a 'Stream' is empty
-null :: Stream a -> Bool
-{-# INLINE null #-}
-null = unId . M.null
-
--- Construction
--- ------------
-
--- | Empty 'Stream'
-empty :: Stream a
-{-# INLINE empty #-}
-empty = M.empty
-
--- | Singleton 'Stream'
-singleton :: a -> Stream a
-{-# INLINE singleton #-}
-singleton = M.singleton
-
--- | Replicate a value to a given length
-replicate :: Int -> a -> Stream a
-{-# INLINE replicate #-}
-replicate = M.replicate
-
--- | Generate a stream from its indices
-generate :: Int -> (Int -> a) -> Stream a
-{-# INLINE generate #-}
-generate = M.generate
-
--- | Prepend an element
-cons :: a -> Stream a -> Stream a
-{-# INLINE cons #-}
-cons = M.cons
-
--- | Append an element
-snoc :: Stream a -> a -> Stream a
-{-# INLINE snoc #-}
-snoc = M.snoc
-
-infixr 5 ++
--- | Concatenate two 'Stream's
-(++) :: Stream a -> Stream a -> Stream a
-{-# INLINE (++) #-}
-(++) = (M.++)
-
--- Accessing elements
--- ------------------
-
--- | First element of the 'Stream' or error if empty
-head :: Stream a -> a
-{-# INLINE head #-}
-head = unId . M.head
-
--- | Last element of the 'Stream' or error if empty
-last :: Stream a -> a
-{-# INLINE last #-}
-last = unId . M.last
-
-infixl 9 !!
--- | Element at the given position
-(!!) :: Stream a -> Int -> a
-{-# INLINE (!!) #-}
-s !! i = unId (s M.!! i)
-
-infixl 9 !?
--- | Element at the given position or 'Nothing' if out of bounds
-(!?) :: Stream a -> Int -> Maybe a
-{-# INLINE (!?) #-}
-s !? i = unId (s M.!? i)
-
--- Substreams
--- ----------
-
--- | Extract a substream of the given length starting at the given position.
-slice :: Int   -- ^ starting index
-      -> Int   -- ^ length
-      -> Stream a
-      -> Stream a
-{-# INLINE slice #-}
-slice = M.slice
-
--- | All but the last element
-init :: Stream a -> Stream a
-{-# INLINE init #-}
-init = M.init
-
--- | All but the first element
-tail :: Stream a -> Stream a
-{-# INLINE tail #-}
-tail = M.tail
-
--- | The first @n@ elements
-take :: Int -> Stream a -> Stream a
-{-# INLINE take #-}
-take = M.take
-
--- | All but the first @n@ elements
-drop :: Int -> Stream a -> Stream a
-{-# INLINE drop #-}
-drop = M.drop
-
--- Mapping
--- ---------------
-
--- | Map a function over a 'Stream'
-map :: (a -> b) -> Stream a -> Stream b
-{-# INLINE map #-}
-map = M.map
-
-unbox :: Stream (Box a) -> Stream a
-{-# INLINE unbox #-}
-unbox = M.unbox
-
-concatMap :: (a -> Stream b) -> Stream a -> Stream b
-{-# INLINE concatMap #-}
-concatMap = M.concatMap
-
--- Zipping
--- -------
-
--- | Pair each element in a 'Stream' with its index
-indexed :: Stream a -> Stream (Int,a)
-{-# INLINE indexed #-}
-indexed = M.indexed
-
--- | Pair each element in a 'Stream' with its index, starting from the right
--- and counting down
-indexedR :: Int -> Stream a -> Stream (Int,a)
-{-# INLINE_STREAM indexedR #-}
-indexedR = M.indexedR
-
--- | Zip two 'Stream's with the given function
-zipWith :: (a -> b -> c) -> Stream a -> Stream b -> Stream c
-{-# INLINE zipWith #-}
-zipWith = M.zipWith
-
--- | Zip three 'Stream's with the given function
-zipWith3 :: (a -> b -> c -> d) -> Stream a -> Stream b -> Stream c -> Stream d
-{-# INLINE zipWith3 #-}
-zipWith3 = M.zipWith3
-
-zipWith4 :: (a -> b -> c -> d -> e)
-                    -> Stream a -> Stream b -> Stream c -> Stream d
-                    -> Stream e
-{-# INLINE zipWith4 #-}
-zipWith4 = M.zipWith4
-
-zipWith5 :: (a -> b -> c -> d -> e -> f)
-                    -> Stream a -> Stream b -> Stream c -> Stream d
-                    -> Stream e -> Stream f
-{-# INLINE zipWith5 #-}
-zipWith5 = M.zipWith5
-
-zipWith6 :: (a -> b -> c -> d -> e -> f -> g)
-                    -> Stream a -> Stream b -> Stream c -> Stream d
-                    -> Stream e -> Stream f -> Stream g
-{-# INLINE zipWith6 #-}
-zipWith6 = M.zipWith6
-
-zip :: Stream a -> Stream b -> Stream (a,b)
-{-# INLINE zip #-}
-zip = M.zip
-
-zip3 :: Stream a -> Stream b -> Stream c -> Stream (a,b,c)
-{-# INLINE zip3 #-}
-zip3 = M.zip3
-
-zip4 :: Stream a -> Stream b -> Stream c -> Stream d
-                -> Stream (a,b,c,d)
-{-# INLINE zip4 #-}
-zip4 = M.zip4
-
-zip5 :: Stream a -> Stream b -> Stream c -> Stream d
-                -> Stream e -> Stream (a,b,c,d,e)
-{-# INLINE zip5 #-}
-zip5 = M.zip5
-
-zip6 :: Stream a -> Stream b -> Stream c -> Stream d
-                -> Stream e -> Stream f -> Stream (a,b,c,d,e,f)
-{-# INLINE zip6 #-}
-zip6 = M.zip6
-
--- Filtering
--- ---------
-
--- | Drop elements which do not satisfy the predicate
-filter :: (a -> Bool) -> Stream a -> Stream a
-{-# INLINE filter #-}
-filter = M.filter
-
--- | Longest prefix of elements that satisfy the predicate
-takeWhile :: (a -> Bool) -> Stream a -> Stream a
-{-# INLINE takeWhile #-}
-takeWhile = M.takeWhile
-
--- | Drop the longest prefix of elements that satisfy the predicate
-dropWhile :: (a -> Bool) -> Stream a -> Stream a
-{-# INLINE dropWhile #-}
-dropWhile = M.dropWhile
-
--- Searching
--- ---------
-
-infix 4 `elem`
--- | Check whether the 'Stream' contains an element
-elem :: Eq a => a -> Stream a -> Bool
-{-# INLINE elem #-}
-elem x = unId . M.elem x
-
-infix 4 `notElem`
--- | Inverse of `elem`
-notElem :: Eq a => a -> Stream a -> Bool
-{-# INLINE notElem #-}
-notElem x = unId . M.notElem x
-
--- | Yield 'Just' the first element matching the predicate or 'Nothing' if no
--- such element exists.
-find :: (a -> Bool) -> Stream a -> Maybe a
-{-# INLINE find #-}
-find f = unId . M.find f
-
--- | Yield 'Just' the index of the first element matching the predicate or
--- 'Nothing' if no such element exists.
-findIndex :: (a -> Bool) -> Stream a -> Maybe Int
-{-# INLINE findIndex #-}
-findIndex f = unId . M.findIndex f
-
--- Folding
--- -------
-
--- | Left fold
-foldl :: (a -> b -> a) -> a -> Stream b -> a
-{-# INLINE foldl #-}
-foldl f z = unId . M.foldl f z
-
--- | Left fold on non-empty 'Stream's
-foldl1 :: (a -> a -> a) -> Stream a -> a
-{-# INLINE foldl1 #-}
-foldl1 f = unId . M.foldl1 f
-
--- | Left fold with strict accumulator
-foldl' :: (a -> b -> a) -> a -> Stream b -> a
-{-# INLINE foldl' #-}
-foldl' f z = unId . M.foldl' f z
-
--- | Left fold on non-empty 'Stream's with strict accumulator
-foldl1' :: (a -> a -> a) -> Stream a -> a
-{-# INLINE foldl1' #-}
-foldl1' f = unId . M.foldl1' f
-
--- | Right fold
-foldr :: (a -> b -> b) -> b -> Stream a -> b
-{-# INLINE foldr #-}
-foldr f z = unId . M.foldr f z
-
--- | Right fold on non-empty 'Stream's
-foldr1 :: (a -> a -> a) -> Stream a -> a
-{-# INLINE foldr1 #-}
-foldr1 f = unId . M.foldr1 f
-
--- Specialised folds
--- -----------------
-
-and :: Stream Bool -> Bool
-{-# INLINE and #-}
-and = unId . M.and
-
-or :: Stream Bool -> Bool
-{-# INLINE or #-}
-or = unId . M.or
-
--- Unfolding
--- ---------
-
--- | Unfold
-unfoldr :: (s -> Maybe (a, s)) -> s -> Stream a
-{-# INLINE unfoldr #-}
-unfoldr = M.unfoldr
-
--- | Unfold at most @n@ elements
-unfoldrN :: Int -> (s -> Maybe (a, s)) -> s -> Stream a
-{-# INLINE unfoldrN #-}
-unfoldrN = M.unfoldrN
-
--- | Apply function n-1 times to value. Zeroth element is original value.
-iterateN :: Int -> (a -> a) -> a -> Stream a
-{-# INLINE iterateN #-}
-iterateN = M.iterateN
-
--- Scans
--- -----
-
--- | Prefix scan
-prescanl :: (a -> b -> a) -> a -> Stream b -> Stream a
-{-# INLINE prescanl #-}
-prescanl = M.prescanl
-
--- | Prefix scan with strict accumulator
-prescanl' :: (a -> b -> a) -> a -> Stream b -> Stream a
-{-# INLINE prescanl' #-}
-prescanl' = M.prescanl'
-
--- | Suffix scan
-postscanl :: (a -> b -> a) -> a -> Stream b -> Stream a
-{-# INLINE postscanl #-}
-postscanl = M.postscanl
-
--- | Suffix scan with strict accumulator
-postscanl' :: (a -> b -> a) -> a -> Stream b -> Stream a
-{-# INLINE postscanl' #-}
-postscanl' = M.postscanl'
-
--- | Haskell-style scan
-scanl :: (a -> b -> a) -> a -> Stream b -> Stream a
-{-# INLINE scanl #-}
-scanl = M.scanl
-
--- | Haskell-style scan with strict accumulator
-scanl' :: (a -> b -> a) -> a -> Stream b -> Stream a
-{-# INLINE scanl' #-}
-scanl' = M.scanl'
-
--- | Scan over a non-empty 'Stream'
-scanl1 :: (a -> a -> a) -> Stream a -> Stream a
-{-# INLINE scanl1 #-}
-scanl1 = M.scanl1
-
--- | Scan over a non-empty 'Stream' with a strict accumulator
-scanl1' :: (a -> a -> a) -> Stream a -> Stream a
-{-# INLINE scanl1' #-}
-scanl1' = M.scanl1'
-
-
--- Comparisons
--- -----------
-
--- FIXME: Move these to Monadic
-
--- | Check if two 'Stream's are equal
-eq :: Eq a => Stream a -> Stream a -> Bool
-{-# INLINE_STREAM eq #-}
-eq (M.Stream step1 s1 _) (M.Stream step2 s2 _) = eq_loop0 SPEC s1 s2
-  where
-    eq_loop0 !sPEC s1 s2 = case unId (step1 s1) of
-                             Yield x s1' -> eq_loop1 SPEC x s1' s2
-                             Skip    s1' -> eq_loop0 SPEC   s1' s2
-                             Done        -> null (M.Stream step2 s2 Unknown)
-
-    eq_loop1 !sPEC x s1 s2 = case unId (step2 s2) of
-                               Yield y s2' -> x == y && eq_loop0 SPEC   s1 s2'
-                               Skip    s2' ->           eq_loop1 SPEC x s1 s2'
-                               Done        -> False
-
--- | Lexicographically compare two 'Stream's
-cmp :: Ord a => Stream a -> Stream a -> Ordering
-{-# INLINE_STREAM cmp #-}
-cmp (M.Stream step1 s1 _) (M.Stream step2 s2 _) = cmp_loop0 SPEC s1 s2
-  where
-    cmp_loop0 !sPEC s1 s2 = case unId (step1 s1) of
-                              Yield x s1' -> cmp_loop1 SPEC x s1' s2
-                              Skip    s1' -> cmp_loop0 SPEC   s1' s2
-                              Done        -> if null (M.Stream step2 s2 Unknown)
-                                               then EQ else LT
-
-    cmp_loop1 !sPEC x s1 s2 = case unId (step2 s2) of
-                                Yield y s2' -> case x `compare` y of
-                                                 EQ -> cmp_loop0 SPEC s1 s2'
-                                                 c  -> c
-                                Skip    s2' -> cmp_loop1 SPEC x s1 s2'
-                                Done        -> GT
-
-instance Eq a => Eq (M.Stream Id a) where
-  {-# INLINE (==) #-}
-  (==) = eq
-
-instance Ord a => Ord (M.Stream Id a) where
-  {-# INLINE compare #-}
-  compare = cmp
-
--- Monadic combinators
--- -------------------
-
--- | Apply a monadic action to each element of the stream, producing a monadic
--- stream of results
-mapM :: Monad m => (a -> m b) -> Stream a -> M.Stream m b
-{-# INLINE mapM #-}
-mapM f = M.mapM f . liftStream
-
--- | Apply a monadic action to each element of the stream
-mapM_ :: Monad m => (a -> m b) -> Stream a -> m ()
-{-# INLINE mapM_ #-}
-mapM_ f = M.mapM_ f . liftStream
-
-zipWithM :: Monad m => (a -> b -> m c) -> Stream a -> Stream b -> M.Stream m c
-{-# INLINE zipWithM #-}
-zipWithM f as bs = M.zipWithM f (liftStream as) (liftStream bs)
-
-zipWithM_ :: Monad m => (a -> b -> m c) -> Stream a -> Stream b -> m ()
-{-# INLINE zipWithM_ #-}
-zipWithM_ f as bs = M.zipWithM_ f (liftStream as) (liftStream bs)
-
--- | Yield a monadic stream of elements that satisfy the monadic predicate
-filterM :: Monad m => (a -> m Bool) -> Stream a -> M.Stream m a
-{-# INLINE filterM #-}
-filterM f = M.filterM f . liftStream
-
--- | Monadic fold
-foldM :: Monad m => (a -> b -> m a) -> a -> Stream b -> m a
-{-# INLINE foldM #-}
-foldM m z = M.foldM m z . liftStream
-
--- | Monadic fold over non-empty stream
-fold1M :: Monad m => (a -> a -> m a) -> Stream a -> m a
-{-# INLINE fold1M #-}
-fold1M m = M.fold1M m . liftStream
-
--- | Monadic fold with strict accumulator
-foldM' :: Monad m => (a -> b -> m a) -> a -> Stream b -> m a
-{-# INLINE foldM' #-}
-foldM' m z = M.foldM' m z . liftStream
-
--- | Monad fold over non-empty stream with strict accumulator
-fold1M' :: Monad m => (a -> a -> m a) -> Stream a -> m a
-{-# INLINE fold1M' #-}
-fold1M' m = M.fold1M' m . liftStream
-
--- Enumerations
--- ------------
-
--- | Yield a 'Stream' of the given length containing the values @x@, @x+y@,
--- @x+y+y@ etc.
-enumFromStepN :: Num a => a -> a -> Int -> Stream a
-{-# INLINE enumFromStepN #-}
-enumFromStepN = M.enumFromStepN
-
--- | Enumerate values
---
--- /WARNING:/ This operations can be very inefficient. If at all possible, use
--- 'enumFromStepN' instead.
-enumFromTo :: Enum a => a -> a -> Stream a
-{-# INLINE enumFromTo #-}
-enumFromTo = M.enumFromTo
-
--- | Enumerate values with a given step.
---
--- /WARNING:/ This operations is very inefficient. If at all possible, use
--- 'enumFromStepN' instead.
-enumFromThenTo :: Enum a => a -> a -> a -> Stream a
-{-# INLINE enumFromThenTo #-}
-enumFromThenTo = M.enumFromThenTo
-
--- Conversions
--- -----------
-
--- | Convert a 'Stream' to a list
-toList :: Stream a -> [a]
-{-# INLINE toList #-}
--- toList s = unId (M.toList s)
-toList s = build (\c n -> toListFB c n s)
-
--- This supports foldr/build list fusion that GHC implements
-toListFB :: (a -> b -> b) -> b -> Stream a -> b
-{-# INLINE [0] toListFB #-}
-toListFB c n (M.Stream step s _) = go s
-  where
-    go s = case unId (step s) of
-             Yield x s' -> x `c` go s'
-             Skip    s' -> go s'
-             Done       -> n
-
--- | Create a 'Stream' from a list
-fromList :: [a] -> Stream a
-{-# INLINE fromList #-}
-fromList = M.fromList
-
--- | Create a 'Stream' from the first @n@ elements of a list
---
--- > fromListN n xs = fromList (take n xs)
-fromListN :: Int -> [a] -> Stream a
-{-# INLINE fromListN #-}
-fromListN = M.fromListN
-
-unsafeFromList :: Size -> [a] -> Stream a
-{-# INLINE unsafeFromList #-}
-unsafeFromList = M.unsafeFromList
-
--- | Create a 'Stream' of values from a 'Stream' of streamable things
-flatten :: (a -> s) -> (s -> Step s b) -> Size -> Stream a -> Stream b
-{-# INLINE_STREAM flatten #-}
-flatten mk istep sz = M.flatten (return . mk) (return . istep) sz . liftStream
-
diff --git a/Data/Vector/Fusion/Stream/Monadic.hs b/Data/Vector/Fusion/Stream/Monadic.hs
--- a/Data/Vector/Fusion/Stream/Monadic.hs
+++ b/Data/Vector/Fusion/Stream/Monadic.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE ExistentialQuantification, Rank2Types, BangPatterns #-}
+{-# LANGUAGE CPP, ExistentialQuantification, MultiParamTypeClasses, FlexibleInstances, Rank2Types, BangPatterns, KindSignatures, GADTs, ScopedTypeVariables #-}
 
 -- |
 -- Module      : Data.Vector.Fusion.Stream.Monadic
@@ -15,9 +15,6 @@
 module Data.Vector.Fusion.Stream.Monadic (
   Stream(..), Step(..), SPEC(..),
 
-  -- * Size hints
-  size, sized,
-
   -- * Length
   length, null,
 
@@ -32,13 +29,16 @@
 
   -- * Mapping
   map, mapM, mapM_, trans, unbox, concatMap, flatten,
-  
+
   -- * Zipping
   indexed, indexedR, zipWithM_,
   zipWithM, zipWith3M, zipWith4M, zipWith5M, zipWith6M,
   zipWith, zipWith3, zipWith4, zipWith5, zipWith6,
   zip, zip3, zip4, zip5, zip6,
 
+  -- * Comparisons
+  eq, cmp,
+
   -- * Filtering
   filter, filterM, takeWhile, takeWhileM, dropWhile, dropWhileM,
 
@@ -68,11 +68,10 @@
   enumFromStepN, enumFromTo, enumFromThenTo,
 
   -- * Conversions
-  toList, fromList, fromListN, unsafeFromList
+  toList, fromList, fromListN
 ) where
 
-import Data.Vector.Fusion.Stream.Size
-import Data.Vector.Fusion.Util ( Box(..), delay_inline )
+import Data.Vector.Fusion.Util ( Box(..) )
 
 import Data.Char      ( ord )
 import GHC.Base       ( unsafeChr )
@@ -93,67 +92,75 @@
 import Data.Int  ( Int8, Int16, Int32, Int64 )
 import Data.Word ( Word8, Word16, Word32, Word, Word64 )
 
-#if __GLASGOW_HASKELL__ >= 700
+#if __GLASGOW_HASKELL__ >= 708
+import GHC.Types ( SPEC(..) )
+#elif __GLASGOW_HASKELL__ >= 700
 import GHC.Exts ( SpecConstrAnnotation(..) )
 #endif
 
 #include "vector.h"
+#include "MachDeps.h"
 
+#if __GLASGOW_HASKELL__ < 708
 data SPEC = SPEC | SPEC2
 #if __GLASGOW_HASKELL__ >= 700
 {-# ANN type SPEC ForceSpecConstr #-}
 #endif
+#endif
 
 emptyStream :: String
 {-# NOINLINE emptyStream #-}
 emptyStream = "empty stream"
 
-#define EMPTY_STREAM (\s -> ERROR s emptyStream)
+#define EMPTY_STREAM (\state -> ERROR state emptyStream)
 
 -- | Result of taking a single step in a stream
-data Step s a = Yield a s  -- ^ a new element and a new seed
-              | Skip    s  -- ^ just a new seed
-              | Done       -- ^ end of stream
-
--- | Monadic streams
-data Stream m a = forall s. Stream (s -> m (Step s a)) s Size
+data Step s a where
+  Yield :: a -> s -> Step s a
+  Skip  :: s -> Step s a
+  Done  :: Step s a
 
--- | 'Size' hint of a 'Stream'
-size :: Stream m a -> Size
-{-# INLINE size #-}
-size (Stream _ _ sz) = sz
+instance Functor (Step s) where
+  {-# INLINE fmap #-}
+  fmap f (Yield x s) = Yield (f x) s
+  fmap _ (Skip s) = Skip s
+  fmap _ Done = Done
 
--- | Attach a 'Size' hint to a 'Stream'
-sized :: Stream m a -> Size -> Stream m a
-{-# INLINE_STREAM sized #-}
-sized (Stream step s _) sz = Stream step s sz
+-- | Monadic streams
+data Stream m a = forall s. Stream (s -> m (Step s a)) s
 
 -- Length
 -- ------
 
 -- | Length of a 'Stream'
 length :: Monad m => Stream m a -> m Int
-{-# INLINE_STREAM length #-}
-length s = foldl' (\n _ -> n+1) 0 s
+{-# INLINE_FUSED length #-}
+length = foldl' (\n _ -> n+1) 0
 
 -- | Check if a 'Stream' is empty
 null :: Monad m => Stream m a -> m Bool
-{-# INLINE_STREAM null #-}
-null s = foldr (\_ _ -> False) True s
-
+{-# INLINE_FUSED null #-}
+null (Stream step t) = null_loop t
+  where
+    null_loop s = do
+      r <- step s
+      case r of
+        Yield _ _ -> return False
+        Skip s'   -> null_loop s'
+        Done      -> return True
 
 -- Construction
 -- ------------
 
 -- | Empty 'Stream'
 empty :: Monad m => Stream m a
-{-# INLINE_STREAM empty #-}
-empty = Stream (const (return Done)) () (Exact 0)
+{-# INLINE_FUSED empty #-}
+empty = Stream (const (return Done)) ()
 
 -- | Singleton 'Stream'
 singleton :: Monad m => a -> Stream m a
-{-# INLINE_STREAM singleton #-}
-singleton x = Stream (return . step) True (Exact 1)
+{-# INLINE_FUSED singleton #-}
+singleton x = Stream (return . step) True
   where
     {-# INLINE_INNER step #-}
     step True  = Yield x False
@@ -161,16 +168,14 @@
 
 -- | Replicate a value to a given length
 replicate :: Monad m => Int -> a -> Stream m a
-{-# INLINE replicate #-}
+{-# INLINE_FUSED replicate #-}
 replicate n x = replicateM n (return x)
 
 -- | Yield a 'Stream' of values obtained by performing the monadic action the
 -- given number of times
 replicateM :: Monad m => Int -> m a -> Stream m a
-{-# INLINE_STREAM replicateM #-}
--- NOTE: We delay inlining max here because GHC will create a join point for
--- the call to newArray# otherwise which is not really nice.
-replicateM n p = Stream step n (Exact (delay_inline max n 0))
+{-# INLINE_FUSED replicateM #-}
+replicateM n p = Stream step n
   where
     {-# INLINE_INNER step #-}
     step i | i <= 0    = return Done
@@ -182,8 +187,8 @@
 
 -- | Generate a stream from its indices
 generateM :: Monad m => Int -> (Int -> m a) -> Stream m a
-{-# INLINE_STREAM generateM #-}
-generateM n f = n `seq` Stream step 0 (Exact (delay_inline max n 0))
+{-# INLINE_FUSED generateM #-}
+generateM n f = n `seq` Stream step 0
   where
     {-# INLINE_INNER step #-}
     step i | i < n     = do
@@ -204,8 +209,8 @@
 infixr 5 ++
 -- | Concatenate two 'Stream's
 (++) :: Monad m => Stream m a -> Stream m a -> Stream m a
-{-# INLINE_STREAM (++) #-}
-Stream stepa sa na ++ Stream stepb sb nb = Stream step (Left sa) (na + nb)
+{-# INLINE_FUSED (++) #-}
+Stream stepa ta ++ Stream stepb tb = Stream step (Left ta)
   where
     {-# INLINE_INNER step #-}
     step (Left  sa) = do
@@ -213,7 +218,7 @@
                         case r of
                           Yield x sa' -> return $ Yield x (Left  sa')
                           Skip    sa' -> return $ Skip    (Left  sa')
-                          Done        -> return $ Skip    (Right sb)
+                          Done        -> return $ Skip    (Right tb)
     step (Right sb) = do
                         r <- stepb sb
                         case r of
@@ -226,10 +231,10 @@
 
 -- | First element of the 'Stream' or error if empty
 head :: Monad m => Stream m a -> m a
-{-# INLINE_STREAM head #-}
-head (Stream step s _) = head_loop SPEC s
+{-# INLINE_FUSED head #-}
+head (Stream step t) = head_loop SPEC t
   where
-    head_loop !sPEC s
+    head_loop !_ s
       = do
           r <- step s
           case r of
@@ -241,10 +246,10 @@
 
 -- | Last element of the 'Stream' or error if empty
 last :: Monad m => Stream m a -> m a
-{-# INLINE_STREAM last #-}
-last (Stream step s _) = last_loop0 SPEC s
+{-# INLINE_FUSED last #-}
+last (Stream step t) = last_loop0 SPEC t
   where
-    last_loop0 !sPEC s
+    last_loop0 !_ s
       = do
           r <- step s
           case r of
@@ -252,7 +257,7 @@
             Skip    s' -> last_loop0 SPEC   s'
             Done       -> EMPTY_STREAM "last"
 
-    last_loop1 !sPEC x s
+    last_loop1 !_ x s
       = do
           r <- step s
           case r of
@@ -264,10 +269,10 @@
 -- | Element at the given position
 (!!) :: Monad m => Stream m a -> Int -> m a
 {-# INLINE (!!) #-}
-Stream step s _ !! i | i < 0     = ERROR "!!" "negative index"
-                     | otherwise = index_loop SPEC s i
+Stream step t !! j | j < 0     = ERROR "!!" "negative index"
+                   | otherwise = index_loop SPEC t j
   where
-    index_loop !sPEC s i
+    index_loop !_ s i
       = i `seq`
         do
           r <- step s
@@ -281,9 +286,9 @@
 -- | Element at the given position or 'Nothing' if out of bounds
 (!?) :: Monad m => Stream m a -> Int -> m (Maybe a)
 {-# INLINE (!?) #-}
-Stream step s _ !? i = index_loop SPEC s i
+Stream step t !? j = index_loop SPEC t j
   where
-    index_loop !sPEC s i
+    index_loop !_ s i
       = i `seq`
         do
           r <- step s
@@ -306,8 +311,8 @@
 
 -- | All but the last element
 init :: Monad m => Stream m a -> Stream m a
-{-# INLINE_STREAM init #-}
-init (Stream step s sz) = Stream step' (Nothing, s) (sz - 1)
+{-# INLINE_FUSED init #-}
+init (Stream step t) = Stream step' (Nothing, t)
   where
     {-# INLINE_INNER step' #-}
     step' (Nothing, s) = liftM (\r ->
@@ -317,7 +322,7 @@
                              Done       -> EMPTY_STREAM "init"
                          ) (step s)
 
-    step' (Just x,  s) = liftM (\r -> 
+    step' (Just x,  s) = liftM (\r ->
                            case r of
                              Yield y s' -> Yield x (Just y, s')
                              Skip    s' -> Skip    (Just x, s')
@@ -326,13 +331,13 @@
 
 -- | All but the first element
 tail :: Monad m => Stream m a -> Stream m a
-{-# INLINE_STREAM tail #-}
-tail (Stream step s sz) = Stream step' (Left s) (sz - 1)
+{-# INLINE_FUSED tail #-}
+tail (Stream step t) = Stream step' (Left t)
   where
     {-# INLINE_INNER step' #-}
     step' (Left  s) = liftM (\r ->
                         case r of
-                          Yield x s' -> Skip (Right s')
+                          Yield _ s' -> Skip (Right s')
                           Skip    s' -> Skip (Left  s')
                           Done       -> EMPTY_STREAM "tail"
                       ) (step s)
@@ -346,8 +351,8 @@
 
 -- | The first @n@ elements
 take :: Monad m => Int -> Stream m a -> Stream m a
-{-# INLINE_STREAM take #-}
-take n (Stream step s sz) = Stream step' (s, 0) (smaller (Exact n) sz)
+{-# INLINE_FUSED take #-}
+take n (Stream step t) = n `seq` Stream step' (t, 0)
   where
     {-# INLINE_INNER step' #-}
     step' (s, i) | i < n = liftM (\r ->
@@ -356,17 +361,17 @@
                                Skip    s' -> Skip    (s', i)
                                Done       -> Done
                            ) (step s)
-    step' (s, i) = return Done
+    step' (_, _) = return Done
 
 -- | All but the first @n@ elements
 drop :: Monad m => Int -> Stream m a -> Stream m a
-{-# INLINE_STREAM drop #-}
-drop n (Stream step s sz) = Stream step' (s, Just n) (sz - Exact n)
+{-# INLINE_FUSED drop #-}
+drop n (Stream step t) = Stream step' (t, Just n)
   where
     {-# INLINE_INNER step' #-}
     step' (s, Just i) | i > 0 = liftM (\r ->
                                 case r of
-                                   Yield x s' -> Skip (s', Just (i-1))
+                                   Yield _ s' -> Skip (s', Just (i-1))
                                    Skip    s' -> Skip (s', Just i)
                                    Done       -> Done
                                 ) (step s)
@@ -378,7 +383,7 @@
                              Skip    s' -> Skip    (s', Nothing)
                              Done       -> Done
                            ) (step s)
-                     
+
 -- Mapping
 -- -------
 
@@ -394,8 +399,8 @@
 
 -- | Map a monadic function over a 'Stream'
 mapM :: Monad m => (a -> m b) -> Stream m a -> Stream m b
-{-# INLINE_STREAM mapM #-}
-mapM f (Stream step s n) = Stream step' s n
+{-# INLINE_FUSED mapM #-}
+mapM f (Stream step t) = Stream step' t
   where
     {-# INLINE_INNER step' #-}
     step' s = do
@@ -406,10 +411,10 @@
                   Done       -> return Done
 
 consume :: Monad m => Stream m a -> m ()
-{-# INLINE_STREAM consume #-}
-consume (Stream step s _) = consume_loop SPEC s
+{-# INLINE_FUSED consume #-}
+consume (Stream step t) = consume_loop SPEC t
   where
-    consume_loop !sPEC s
+    consume_loop !_ s
       = do
           r <- step s
           case r of
@@ -419,18 +424,18 @@
 
 -- | Execute a monadic action for each element of the 'Stream'
 mapM_ :: Monad m => (a -> m b) -> Stream m a -> m ()
-{-# INLINE_STREAM mapM_ #-}
+{-# INLINE_FUSED mapM_ #-}
 mapM_ m = consume . mapM m
 
 -- | Transform a 'Stream' to use a different monad
-trans :: (Monad m, Monad m') => (forall a. m a -> m' a)
-                             -> Stream m a -> Stream m' a
-{-# INLINE_STREAM trans #-}
-trans f (Stream step s n) = Stream (f . step) s n
+trans :: (Monad m, Monad m')
+      => (forall z. m z -> m' z) -> Stream m a -> Stream m' a
+{-# INLINE_FUSED trans #-}
+trans f (Stream step s) = Stream (f . step) s
 
 unbox :: Monad m => Stream m (Box a) -> Stream m a
-{-# INLINE_STREAM unbox #-}
-unbox (Stream step s n) = Stream step' s n
+{-# INLINE_FUSED unbox #-}
+unbox (Stream step t) = Stream step' t
   where
     {-# INLINE_INNER step' #-}
     step' s = do
@@ -445,8 +450,8 @@
 
 -- | Pair each element in a 'Stream' with its index
 indexed :: Monad m => Stream m a -> Stream m (Int,a)
-{-# INLINE_STREAM indexed #-}
-indexed (Stream step s n) = Stream step' (s,0) n
+{-# INLINE_FUSED indexed #-}
+indexed (Stream step t) = Stream step' (t,0)
   where
     {-# INLINE_INNER step' #-}
     step' (s,i) = i `seq`
@@ -460,8 +465,8 @@
 -- | Pair each element in a 'Stream' with its index, starting from the right
 -- and counting down
 indexedR :: Monad m => Int -> Stream m a -> Stream m (Int,a)
-{-# INLINE_STREAM indexedR #-}
-indexedR m (Stream step s n) = Stream step' (s,m) n
+{-# INLINE_FUSED indexedR #-}
+indexedR m (Stream step t) = Stream step' (t,m)
   where
     {-# INLINE_INNER step' #-}
     step' (s,i) = i `seq`
@@ -476,9 +481,8 @@
 
 -- | Zip two 'Stream's with the given monadic function
 zipWithM :: Monad m => (a -> b -> m c) -> Stream m a -> Stream m b -> Stream m c
-{-# INLINE_STREAM zipWithM #-}
-zipWithM f (Stream stepa sa na) (Stream stepb sb nb)
-  = Stream step (sa, sb, Nothing) (smaller na nb)
+{-# INLINE_FUSED zipWithM #-}
+zipWithM f (Stream stepa ta) (Stream stepb tb) = Stream step (ta, tb, Nothing)
   where
     {-# INLINE_INNER step #-}
     step (sa, sb, Nothing) = liftM (\r ->
@@ -502,18 +506,18 @@
 {-# RULES
 
 "zipWithM xs xs [Vector.Stream]" forall f xs.
-  zipWithM f xs xs = mapM (\x -> f x x) xs
+  zipWithM f xs xs = mapM (\x -> f x x) xs   #-}
 
-  #-}
 
 zipWithM_ :: Monad m => (a -> b -> m c) -> Stream m a -> Stream m b -> m ()
 {-# INLINE zipWithM_ #-}
 zipWithM_ f sa sb = consume (zipWithM f sa sb)
 
 zipWith3M :: Monad m => (a -> b -> c -> m d) -> Stream m a -> Stream m b -> Stream m c -> Stream m d
-{-# INLINE_STREAM zipWith3M #-}
-zipWith3M f (Stream stepa sa na) (Stream stepb sb nb) (Stream stepc sc nc)
-  = Stream step (sa, sb, sc, Nothing) (smaller na (smaller nb nc))
+{-# INLINE_FUSED zipWith3M #-}
+zipWith3M f (Stream stepa ta)
+            (Stream stepb tb)
+            (Stream stepc tc) = Stream step (ta, tb, tc, Nothing)
   where
     {-# INLINE_INNER step #-}
     step (sa, sb, sc, Nothing) = do
@@ -609,6 +613,65 @@
 {-# INLINE zip6 #-}
 zip6 = zipWith6 (,,,,,)
 
+-- Comparisons
+-- -----------
+
+-- | Check if two 'Stream's are equal
+eq :: (Monad m, Eq a) => Stream m a -> Stream m a -> m Bool
+{-# INLINE_FUSED eq #-}
+eq (Stream step1 t1) (Stream step2 t2) = eq_loop0 SPEC t1 t2
+  where
+    eq_loop0 !_ s1 s2 = do
+      r <- step1 s1
+      case r of
+        Yield x s1' -> eq_loop1 SPEC x s1' s2
+        Skip    s1' -> eq_loop0 SPEC   s1' s2
+        Done        -> eq_null s2
+
+    eq_loop1 !_ x s1 s2 = do
+      r <- step2 s2
+      case r of
+        Yield y s2'
+          | x == y    -> eq_loop0 SPEC   s1 s2'
+          | otherwise -> return False
+        Skip    s2'   -> eq_loop1 SPEC x s1 s2'
+        Done          -> return False
+
+    eq_null s2 = do
+      r <- step2 s2
+      case r of
+        Yield _ _ -> return False
+        Skip s2'  -> eq_null s2'
+        Done      -> return True
+
+-- | Lexicographically compare two 'Stream's
+cmp :: (Monad m, Ord a) => Stream m a -> Stream m a -> m Ordering
+{-# INLINE_FUSED cmp #-}
+cmp (Stream step1 t1) (Stream step2 t2) = cmp_loop0 SPEC t1 t2
+  where
+    cmp_loop0 !_ s1 s2 = do
+      r <- step1 s1
+      case r of
+        Yield x s1' -> cmp_loop1 SPEC x s1' s2
+        Skip    s1' -> cmp_loop0 SPEC   s1' s2
+        Done        -> cmp_null s2
+
+    cmp_loop1 !_ x s1 s2 = do
+      r <- step2 s2
+      case r of
+        Yield y s2' -> case x `compare` y of
+                         EQ -> cmp_loop0 SPEC s1 s2'
+                         c  -> return c
+        Skip    s2' -> cmp_loop1 SPEC x s1 s2'
+        Done        -> return GT
+
+    cmp_null s2 = do
+      r <- step2 s2
+      case r of
+        Yield _ _ -> return LT
+        Skip s2'  -> cmp_null s2'
+        Done      -> return EQ
+
 -- Filtering
 -- ---------
 
@@ -619,8 +682,8 @@
 
 -- | Drop elements which do not satisfy the monadic predicate
 filterM :: Monad m => (a -> m Bool) -> Stream m a -> Stream m a
-{-# INLINE_STREAM filterM #-}
-filterM f (Stream step s n) = Stream step' s (toMax n)
+{-# INLINE_FUSED filterM #-}
+filterM f (Stream step t) = Stream step' t
   where
     {-# INLINE_INNER step' #-}
     step' s = do
@@ -640,8 +703,8 @@
 
 -- | Longest prefix of elements that satisfy the monadic predicate
 takeWhileM :: Monad m => (a -> m Bool) -> Stream m a -> Stream m a
-{-# INLINE_STREAM takeWhileM #-}
-takeWhileM f (Stream step s n) = Stream step' s (toMax n)
+{-# INLINE_FUSED takeWhileM #-}
+takeWhileM f (Stream step t) = Stream step' t
   where
     {-# INLINE_INNER step' #-}
     step' s = do
@@ -662,8 +725,8 @@
 
 -- | Drop the longest prefix of elements that satisfy the monadic predicate
 dropWhileM :: Monad m => (a -> m Bool) -> Stream m a -> Stream m a
-{-# INLINE_STREAM dropWhileM #-}
-dropWhileM f (Stream step s n) = Stream step' (DropWhile_Drop s) (toMax n)
+{-# INLINE_FUSED dropWhileM #-}
+dropWhileM f (Stream step t) = Stream step' (DropWhile_Drop t)
   where
     -- NOTE: we jump through hoops here to have only one Yield; local data
     -- declarations would be nice!
@@ -696,10 +759,10 @@
 infix 4 `elem`
 -- | Check whether the 'Stream' contains an element
 elem :: (Monad m, Eq a) => a -> Stream m a -> m Bool
-{-# INLINE_STREAM elem #-}
-elem x (Stream step s _) = elem_loop SPEC s
+{-# INLINE_FUSED elem #-}
+elem x (Stream step t) = elem_loop SPEC t
   where
-    elem_loop !sPEC s
+    elem_loop !_ s
       = do
           r <- step s
           case r of
@@ -723,10 +786,10 @@
 -- | Yield 'Just' the first element that satisfies the monadic predicate or
 -- 'Nothing' if no such element exists.
 findM :: Monad m => (a -> m Bool) -> Stream m a -> m (Maybe a)
-{-# INLINE_STREAM findM #-}
-findM f (Stream step s _) = find_loop SPEC s
+{-# INLINE_FUSED findM #-}
+findM f (Stream step t) = find_loop SPEC t
   where
-    find_loop !sPEC s
+    find_loop !_ s
       = do
           r <- step s
           case r of
@@ -740,16 +803,16 @@
 -- | Yield 'Just' the index of the first element that satisfies the predicate
 -- or 'Nothing' if no such element exists.
 findIndex :: Monad m => (a -> Bool) -> Stream m a -> m (Maybe Int)
-{-# INLINE_STREAM findIndex #-}
+{-# INLINE_FUSED findIndex #-}
 findIndex f = findIndexM (return . f)
 
 -- | Yield 'Just' the index of the first element that satisfies the monadic
 -- predicate or 'Nothing' if no such element exists.
 findIndexM :: Monad m => (a -> m Bool) -> Stream m a -> m (Maybe Int)
-{-# INLINE_STREAM findIndexM #-}
-findIndexM f (Stream step s _) = findIndex_loop SPEC s 0
+{-# INLINE_FUSED findIndexM #-}
+findIndexM f (Stream step t) = findIndex_loop SPEC t 0
   where
-    findIndex_loop !sPEC s i
+    findIndex_loop !_ s i
       = do
           r <- step s
           case r of
@@ -770,10 +833,10 @@
 
 -- | Left fold with a monadic operator
 foldlM :: Monad m => (a -> b -> m a) -> a -> Stream m b -> m a
-{-# INLINE_STREAM foldlM #-}
-foldlM m z (Stream step s _) = foldlM_loop SPEC z s
+{-# INLINE_FUSED foldlM #-}
+foldlM m w (Stream step t) = foldlM_loop SPEC w t
   where
-    foldlM_loop !sPEC z s
+    foldlM_loop !_ z s
       = do
           r <- step s
           case r of
@@ -793,14 +856,14 @@
 
 -- | Left fold over a non-empty 'Stream' with a monadic operator
 foldl1M :: Monad m => (a -> a -> m a) -> Stream m a -> m a
-{-# INLINE_STREAM foldl1M #-}
-foldl1M f (Stream step s sz) = foldl1M_loop SPEC s
+{-# INLINE_FUSED foldl1M #-}
+foldl1M f (Stream step t) = foldl1M_loop SPEC t
   where
-    foldl1M_loop !sPEC s
+    foldl1M_loop !_ s
       = do
           r <- step s
           case r of
-            Yield x s' -> foldlM f x (Stream step s' (sz - 1))
+            Yield x s' -> foldlM f x (Stream step s')
             Skip    s' -> foldl1M_loop SPEC s'
             Done       -> EMPTY_STREAM "foldl1M"
 
@@ -816,10 +879,10 @@
 
 -- | Left fold with a strict accumulator and a monadic operator
 foldlM' :: Monad m => (a -> b -> m a) -> a -> Stream m b -> m a
-{-# INLINE_STREAM foldlM' #-}
-foldlM' m z (Stream step s _) = foldlM'_loop SPEC z s
+{-# INLINE_FUSED foldlM' #-}
+foldlM' m w (Stream step t) = foldlM'_loop SPEC w t
   where
-    foldlM'_loop !sPEC z s
+    foldlM'_loop !_ z s
       = z `seq`
         do
           r <- step s
@@ -841,14 +904,14 @@
 -- | Left fold over a non-empty 'Stream' with a strict accumulator and a
 -- monadic operator
 foldl1M' :: Monad m => (a -> a -> m a) -> Stream m a -> m a
-{-# INLINE_STREAM foldl1M' #-}
-foldl1M' f (Stream step s sz) = foldl1M'_loop SPEC s
+{-# INLINE_FUSED foldl1M' #-}
+foldl1M' f (Stream step t) = foldl1M'_loop SPEC t
   where
-    foldl1M'_loop !sPEC s
+    foldl1M'_loop !_ s
       = do
           r <- step s
           case r of
-            Yield x s' -> foldlM' f x (Stream step s' (sz - 1))
+            Yield x s' -> foldlM' f x (Stream step s')
             Skip    s' -> foldl1M'_loop SPEC s'
             Done       -> EMPTY_STREAM "foldl1M'"
 
@@ -864,10 +927,10 @@
 
 -- | Right fold with a monadic operator
 foldrM :: Monad m => (a -> b -> m b) -> b -> Stream m a -> m b
-{-# INLINE_STREAM foldrM #-}
-foldrM f z (Stream step s _) = foldrM_loop SPEC s
+{-# INLINE_FUSED foldrM #-}
+foldrM f z (Stream step t) = foldrM_loop SPEC t
   where
-    foldrM_loop !sPEC s
+    foldrM_loop !_ s
       = do
           r <- step s
           case r of
@@ -882,10 +945,10 @@
 
 -- | Right fold over a non-empty stream with a monadic operator
 foldr1M :: Monad m => (a -> a -> m a) -> Stream m a -> m a
-{-# INLINE_STREAM foldr1M #-}
-foldr1M f (Stream step s _) = foldr1M_loop0 SPEC s
+{-# INLINE_FUSED foldr1M #-}
+foldr1M f (Stream step t) = foldr1M_loop0 SPEC t
   where
-    foldr1M_loop0 !sPEC s
+    foldr1M_loop0 !_ s
       = do
           r <- step s
           case r of
@@ -893,7 +956,7 @@
             Skip    s' -> foldr1M_loop0 SPEC   s'
             Done       -> EMPTY_STREAM "foldr1M"
 
-    foldr1M_loop1 !sPEC x s
+    foldr1M_loop1 !_ x s
       = do
           r <- step s
           case r of
@@ -905,10 +968,10 @@
 -- -----------------
 
 and :: Monad m => Stream m Bool -> m Bool
-{-# INLINE_STREAM and #-}
-and (Stream step s _) = and_loop SPEC s
+{-# INLINE_FUSED and #-}
+and (Stream step t) = and_loop SPEC t
   where
-    and_loop !sPEC s
+    and_loop !_ s
       = do
           r <- step s
           case r of
@@ -918,10 +981,10 @@
             Done           -> return True
 
 or :: Monad m => Stream m Bool -> m Bool
-{-# INLINE_STREAM or #-}
-or (Stream step s _) = or_loop SPEC s
+{-# INLINE_FUSED or #-}
+or (Stream step t) = or_loop SPEC t
   where
-    or_loop !sPEC s
+    or_loop !_ s
       = do
           r <- step s
           case r of
@@ -935,8 +998,8 @@
 concatMap f = concatMapM (return . f)
 
 concatMapM :: Monad m => (a -> m (Stream m b)) -> Stream m a -> Stream m b
-{-# INLINE_STREAM concatMapM #-}
-concatMapM f (Stream step s _) = Stream concatMap_go (Left s) Unknown
+{-# INLINE_FUSED concatMapM #-}
+concatMapM f (Stream step t) = Stream concatMap_go (Left t)
   where
     concatMap_go (Left s) = do
         r <- step s
@@ -946,18 +1009,17 @@
                 return $ Skip (Right (b_stream, s'))
             Skip    s' -> return $ Skip (Left s')
             Done       -> return Done
-    concatMap_go (Right (Stream inner_step inner_s sz, s)) = do
+    concatMap_go (Right (Stream inner_step inner_s, s)) = do
         r <- inner_step inner_s
         case r of
-            Yield b inner_s' -> return $ Yield b (Right (Stream inner_step inner_s' sz, s))
-            Skip    inner_s' -> return $ Skip (Right (Stream inner_step inner_s' sz, s))
+            Yield b inner_s' -> return $ Yield b (Right (Stream inner_step inner_s', s))
+            Skip    inner_s' -> return $ Skip (Right (Stream inner_step inner_s', s))
             Done             -> return $ Skip (Left s)
 
 -- | Create a 'Stream' of values from a 'Stream' of streamable things
-flatten :: Monad m => (a -> m s) -> (s -> m (Step s b)) -> Size
-                   -> Stream m a -> Stream m b
-{-# INLINE_STREAM flatten #-}
-flatten mk istep sz (Stream ostep t _) = Stream step (Left t) sz
+flatten :: Monad m => (a -> m s) -> (s -> m (Step s b)) -> Stream m a -> Stream m b
+{-# INLINE_FUSED flatten #-}
+flatten mk istep (Stream ostep u) = Stream step (Left u)
   where
     {-# INLINE_INNER step #-}
     step (Left t) = do
@@ -969,7 +1031,7 @@
                         Skip    t' -> return $ Skip (Left t')
                         Done       -> return $ Done
 
-    
+
     step (Right (s,t)) = do
                            r <- istep s
                            case r of
@@ -982,13 +1044,13 @@
 
 -- | Unfold
 unfoldr :: Monad m => (s -> Maybe (a, s)) -> s -> Stream m a
-{-# INLINE_STREAM unfoldr #-}
+{-# INLINE_FUSED unfoldr #-}
 unfoldr f = unfoldrM (return . f)
 
 -- | Unfold with a monadic function
 unfoldrM :: Monad m => (s -> m (Maybe (a, s))) -> s -> Stream m a
-{-# INLINE_STREAM unfoldrM #-}
-unfoldrM f s = Stream step s Unknown
+{-# INLINE_FUSED unfoldrM #-}
+unfoldrM f t = Stream step t
   where
     {-# INLINE_INNER step #-}
     step s = liftM (\r ->
@@ -997,15 +1059,14 @@
                  Nothing      -> Done
              ) (f s)
 
--- | Unfold at most @n@ elements
 unfoldrN :: Monad m => Int -> (s -> Maybe (a, s)) -> s -> Stream m a
-{-# INLINE_STREAM unfoldrN #-}
+{-# INLINE_FUSED unfoldrN #-}
 unfoldrN n f = unfoldrNM n (return . f)
 
 -- | Unfold at most @n@ elements with a monadic functions
 unfoldrNM :: Monad m => Int -> (s -> m (Maybe (a, s))) -> s -> Stream m a
-{-# INLINE_STREAM unfoldrNM #-}
-unfoldrNM n f s = Stream step (s,n) (Max (delay_inline max n 0))
+{-# INLINE_FUSED unfoldrNM #-}
+unfoldrNM m f t = Stream step (t,m)
   where
     {-# INLINE_INNER step #-}
     step (s,n) | n <= 0    = return Done
@@ -1017,8 +1078,8 @@
 
 -- | Apply monadic function n times to value. Zeroth element is original value.
 iterateNM :: Monad m => Int -> (a -> m a) -> a -> Stream m a
-{-# INLINE_STREAM iterateNM #-}
-iterateNM n f x0 = Stream step (x0,n) (Exact (delay_inline max n 0))
+{-# INLINE_FUSED iterateNM #-}
+iterateNM n f x0 = Stream step (x0,n)
   where
     {-# INLINE_INNER step #-}
     step (x,i) | i <= 0    = return Done
@@ -1028,7 +1089,7 @@
 
 -- | Apply function n times to value. Zeroth element is original value.
 iterateN :: Monad m => Int -> (a -> a) -> a -> Stream m a
-{-# INLINE_STREAM iterateN #-}
+{-# INLINE_FUSED iterateN #-}
 iterateN n f x0 = iterateNM n (return . f) x0
 
 -- Scans
@@ -1041,8 +1102,8 @@
 
 -- | Prefix scan with a monadic operator
 prescanlM :: Monad m => (a -> b -> m a) -> a -> Stream m b -> Stream m a
-{-# INLINE_STREAM prescanlM #-}
-prescanlM f z (Stream step s sz) = Stream step' (s,z) sz
+{-# INLINE_FUSED prescanlM #-}
+prescanlM f w (Stream step t) = Stream step' (t,w)
   where
     {-# INLINE_INNER step' #-}
     step' (s,x) = do
@@ -1061,8 +1122,8 @@
 
 -- | Prefix scan with strict accumulator and a monadic operator
 prescanlM' :: Monad m => (a -> b -> m a) -> a -> Stream m b -> Stream m a
-{-# INLINE_STREAM prescanlM' #-}
-prescanlM' f z (Stream step s sz) = Stream step' (s,z) sz
+{-# INLINE_FUSED prescanlM' #-}
+prescanlM' f w (Stream step t) = Stream step' (t,w)
   where
     {-# INLINE_INNER step' #-}
     step' (s,x) = x `seq`
@@ -1082,8 +1143,8 @@
 
 -- | Suffix scan with a monadic operator
 postscanlM :: Monad m => (a -> b -> m a) -> a -> Stream m b -> Stream m a
-{-# INLINE_STREAM postscanlM #-}
-postscanlM f z (Stream step s sz) = Stream step' (s,z) sz
+{-# INLINE_FUSED postscanlM #-}
+postscanlM f w (Stream step t) = Stream step' (t,w)
   where
     {-# INLINE_INNER step' #-}
     step' (s,x) = do
@@ -1102,8 +1163,8 @@
 
 -- | Suffix scan with strict acccumulator and a monadic operator
 postscanlM' :: Monad m => (a -> b -> m a) -> a -> Stream m b -> Stream m a
-{-# INLINE_STREAM postscanlM' #-}
-postscanlM' f z (Stream step s sz) = z `seq` Stream step' (s,z) sz
+{-# INLINE_FUSED postscanlM' #-}
+postscanlM' f w (Stream step t) = w `seq` Stream step' (t,w)
   where
     {-# INLINE_INNER step' #-}
     step' (s,x) = x `seq`
@@ -1143,8 +1204,8 @@
 
 -- | Scan over a non-empty 'Stream' with a monadic operator
 scanl1M :: Monad m => (a -> a -> m a) -> Stream m a -> Stream m a
-{-# INLINE_STREAM scanl1M #-}
-scanl1M f (Stream step s sz) = Stream step' (s, Nothing) sz
+{-# INLINE_FUSED scanl1M #-}
+scanl1M f (Stream step t) = Stream step' (t, Nothing)
   where
     {-# INLINE_INNER step' #-}
     step' (s, Nothing) = do
@@ -1171,8 +1232,8 @@
 -- | Scan over a non-empty 'Stream' with a strict accumulator and a monadic
 -- operator
 scanl1M' :: Monad m => (a -> a -> m a) -> Stream m a -> Stream m a
-{-# INLINE_STREAM scanl1M' #-}
-scanl1M' f (Stream step s sz) = Stream step' (s, Nothing) sz
+{-# INLINE_FUSED scanl1M' #-}
+scanl1M' f (Stream step t) = Stream step' (t, Nothing)
   where
     {-# INLINE_INNER step' #-}
     step' (s, Nothing) = do
@@ -1202,12 +1263,11 @@
 -- | Yield a 'Stream' of the given length containing the values @x@, @x+y@,
 -- @x+y+y@ etc.
 enumFromStepN :: (Num a, Monad m) => a -> a -> Int -> Stream m a
-{-# INLINE_STREAM enumFromStepN #-}
-enumFromStepN x y n = x `seq` y `seq` n `seq`
-                      Stream step (x,n) (Exact (delay_inline max n 0))
+{-# INLINE_FUSED enumFromStepN #-}
+enumFromStepN x y n = x `seq` y `seq` n `seq` Stream step (x,n)
   where
     {-# INLINE_INNER step #-}
-    step (x,n) | n > 0     = return $ Yield x (x+y,n-1)
+    step (w,m) | m > 0     = return $ Yield w (w+y,m-1)
                | otherwise = return $ Done
 
 -- | Enumerate values
@@ -1215,7 +1275,7 @@
 -- /WARNING:/ This operation can be very inefficient. If at all possible, use
 -- 'enumFromStepN' instead.
 enumFromTo :: (Enum a, Monad m) => a -> a -> Stream m a
-{-# INLINE_STREAM enumFromTo #-}
+{-# INLINE_FUSED enumFromTo #-}
 enumFromTo x y = fromList [x .. y]
 
 -- NOTE: We use (x+1) instead of (succ x) below because the latter checks for
@@ -1223,13 +1283,11 @@
 
 -- FIXME: add "too large" test for Int
 enumFromTo_small :: (Integral a, Monad m) => a -> a -> Stream m a
-{-# INLINE_STREAM enumFromTo_small #-}
-enumFromTo_small x y = x `seq` y `seq` Stream step x (Exact n)
+{-# INLINE_FUSED enumFromTo_small #-}
+enumFromTo_small x y = x `seq` y `seq` Stream step x
   where
-    n = delay_inline max (fromIntegral y - fromIntegral x + 1) 0
-
     {-# INLINE_INNER step #-}
-    step x | x <= y    = return $ Yield x (x+1)
+    step w | w <= y    = return $ Yield w (w+1)
            | otherwise = return $ Done
 
 {-# RULES
@@ -1244,9 +1302,8 @@
   enumFromTo = enumFromTo_small :: Monad m => Word8 -> Word8 -> Stream m Word8
 
 "enumFromTo<Word16> [Stream]"
-  enumFromTo = enumFromTo_small :: Monad m => Word16 -> Word16 -> Stream m Word16
+  enumFromTo = enumFromTo_small :: Monad m => Word16 -> Word16 -> Stream m Word16   #-}
 
-  #-}
 
 #if WORD_SIZE_IN_BITS > 32
 
@@ -1256,9 +1313,8 @@
   enumFromTo = enumFromTo_small :: Monad m => Int32 -> Int32 -> Stream m Int32
 
 "enumFromTo<Word32> [Stream]"
-  enumFromTo = enumFromTo_small :: Monad m => Word32 -> Word32 -> Stream m Word32
+  enumFromTo = enumFromTo_small :: Monad m => Word32 -> Word32 -> Stream m Word32   #-}
 
-  #-}
 
 #endif
 
@@ -1274,22 +1330,31 @@
 -- unsigned types). See http://hackage.haskell.org/trac/ghc/ticket/3744
 --
 
-enumFromTo_int :: (Integral a, Monad m) => a -> a -> Stream m a
-{-# INLINE_STREAM enumFromTo_int #-}
-enumFromTo_int x y = x `seq` y `seq` Stream step x (Exact (len x y))
+enumFromTo_int :: forall m. Monad m => Int -> Int -> Stream m Int
+{-# INLINE_FUSED enumFromTo_int #-}
+enumFromTo_int x y = x `seq` y `seq` Stream step x
   where
-    {-# INLINE [0] len #-}
-    len x y | x > y     = 0
-            | otherwise = BOUNDS_CHECK(check) "enumFromTo" "vector too large"
-                          (n > 0)
-                        $ fromIntegral n
-      where
-        n = y-x+1
+    -- {-# INLINE [0] len #-}
+    -- len :: Int -> Int -> Int
+    -- len u v | u > v     = 0
+    --         | otherwise = BOUNDS_CHECK(check) "enumFromTo" "vector too large"
+    --                       (n > 0)
+    --                     $ n
+    --   where
+    --     n = v-u+1
 
     {-# INLINE_INNER step #-}
-    step x | x <= y    = return $ Yield x (x+1)
+    step z | z <= y    = return $ Yield z (z+1)
            | otherwise = return $ Done
 
+enumFromTo_intlike :: (Integral a, Monad m) => a -> a -> Stream m a
+{-# INLINE_FUSED enumFromTo_intlike #-}
+enumFromTo_intlike x y = x `seq` y `seq` Stream step x
+  where
+    {-# INLINE_INNER step #-}
+    step z | z <= y    = return $ Yield z (z+1)
+           | otherwise = return $ Done
+
 {-# RULES
 
 "enumFromTo<Int> [Stream]"
@@ -1298,31 +1363,21 @@
 #if WORD_SIZE_IN_BITS > 32
 
 "enumFromTo<Int64> [Stream]"
-  enumFromTo = enumFromTo_int :: Monad m => Int64 -> Int64 -> Stream m Int64
+  enumFromTo = enumFromTo_intlike :: Monad m => Int64 -> Int64 -> Stream m Int64 #-}
 
 #else
 
 "enumFromTo<Int32> [Stream]"
-  enumFromTo = enumFromTo_int :: Monad m => Int32 -> Int32 -> Stream m Int32
+  enumFromTo = enumFromTo_intlike :: Monad m => Int32 -> Int32 -> Stream m Int32 #-}
 
 #endif
 
-  #-}
-
 enumFromTo_big_word :: (Integral a, Monad m) => a -> a -> Stream m a
-{-# INLINE_STREAM enumFromTo_big_word #-}
-enumFromTo_big_word x y = x `seq` y `seq` Stream step x (Exact (len x y))
+{-# INLINE_FUSED enumFromTo_big_word #-}
+enumFromTo_big_word x y = x `seq` y `seq` Stream step x
   where
-    {-# INLINE [0] len #-}
-    len x y | x > y     = 0
-            | otherwise = BOUNDS_CHECK(check) "enumFromTo" "vector too large"
-                          (n < fromIntegral (maxBound :: Int))
-                        $ fromIntegral (n+1)
-      where
-        n = y-x
-
     {-# INLINE_INNER step #-}
-    step x | x <= y    = return $ Yield x (x+1)
+    step z | z <= y    = return $ Yield z (z+1)
            | otherwise = return $ Done
 
 {-# RULES
@@ -1344,25 +1399,17 @@
 
 "enumFromTo<Integer> [Stream]"
   enumFromTo = enumFromTo_big_word
-                        :: Monad m => Integer -> Integer -> Stream m Integer
+                        :: Monad m => Integer -> Integer -> Stream m Integer   #-}
 
-  #-}
 
+
 -- FIXME: the "too large" test is totally wrong
 enumFromTo_big_int :: (Integral a, Monad m) => a -> a -> Stream m a
-{-# INLINE_STREAM enumFromTo_big_int #-}
-enumFromTo_big_int x y = x `seq` y `seq` Stream step x (Exact (len x y))
+{-# INLINE_FUSED enumFromTo_big_int #-}
+enumFromTo_big_int x y = x `seq` y `seq` Stream step x
   where
-    {-# INLINE [0] len #-}
-    len x y | x > y     = 0
-            | otherwise = BOUNDS_CHECK(check) "enumFromTo" "vector too large"
-                          (n > 0 && n <= fromIntegral (maxBound :: Int))
-                        $ fromIntegral n
-      where
-        n = y-x+1
-
     {-# INLINE_INNER step #-}
-    step x | x <= y    = return $ Yield x (x+1)
+    step z | z <= y    = return $ Yield z (z+1)
            | otherwise = return $ Done
 
 #if WORD_SIZE_IN_BITS > 32
@@ -1370,51 +1417,41 @@
 {-# RULES
 
 "enumFromTo<Int64> [Stream]"
-  enumFromTo = enumFromTo_big :: Monad m => Int64 -> Int64 -> Stream m Int64
+  enumFromTo = enumFromTo_big_int :: Monad m => Int64 -> Int64 -> Stream m Int64   #-}
 
-  #-}
 
+
 #endif
 
 enumFromTo_char :: Monad m => Char -> Char -> Stream m Char
-{-# INLINE_STREAM enumFromTo_char #-}
-enumFromTo_char x y = x `seq` y `seq` Stream step xn (Exact n)
+{-# INLINE_FUSED enumFromTo_char #-}
+enumFromTo_char x y = x `seq` y `seq` Stream step xn
   where
     xn = ord x
     yn = ord y
 
-    n = delay_inline max 0 (yn - xn + 1)
-
     {-# INLINE_INNER step #-}
-    step xn | xn <= yn  = return $ Yield (unsafeChr xn) (xn+1)
+    step zn | zn <= yn  = return $ Yield (unsafeChr zn) (zn+1)
             | otherwise = return $ Done
 
 {-# RULES
 
 "enumFromTo<Char> [Stream]"
-  enumFromTo = enumFromTo_char
+  enumFromTo = enumFromTo_char   #-}
 
-  #-}
 
+
 ------------------------------------------------------------------------
 
 -- Specialise enumFromTo for Float and Double.
 -- Also, try to do something about pairs?
 
 enumFromTo_double :: (Monad m, Ord a, RealFrac a) => a -> a -> Stream m a
-{-# INLINE_STREAM enumFromTo_double #-}
-enumFromTo_double n m = n `seq` m `seq` Stream step n (Max (len n lim))
+{-# INLINE_FUSED enumFromTo_double #-}
+enumFromTo_double n m = n `seq` m `seq` Stream step n
   where
     lim = m + 1/2 -- important to float out
 
-    {-# INLINE [0] len #-}
-    len x y | x > y     = 0
-            | otherwise = BOUNDS_CHECK(check) "enumFromTo" "vector too large"
-                          (n > 0)
-                        $ fromIntegral n
-      where
-        n = truncate (y-x)+2
-
     {-# INLINE_INNER step #-}
     step x | x <= lim  = return $ Yield x (x+1)
            | otherwise = return $ Done
@@ -1425,10 +1462,10 @@
   enumFromTo = enumFromTo_double :: Monad m => Double -> Double -> Stream m Double
 
 "enumFromTo<Float> [Stream]"
-  enumFromTo = enumFromTo_double :: Monad m => Float -> Float -> Stream m Float
+  enumFromTo = enumFromTo_double :: Monad m => Float -> Float -> Stream m Float   #-}
 
-  #-}
 
+
 ------------------------------------------------------------------------
 
 -- | Enumerate values with a given step.
@@ -1436,7 +1473,7 @@
 -- /WARNING:/ This operation is very inefficient. If at all possible, use
 -- 'enumFromStepN' instead.
 enumFromThenTo :: (Enum a, Monad m) => a -> a -> a -> Stream m a
-{-# INLINE_STREAM enumFromThenTo #-}
+{-# INLINE_FUSED enumFromThenTo #-}
 enumFromThenTo x y z = fromList [x, y .. z]
 
 -- FIXME: Specialise enumFromThenTo.
@@ -1452,23 +1489,110 @@
 -- | Convert a list to a 'Stream'
 fromList :: Monad m => [a] -> Stream m a
 {-# INLINE fromList #-}
-fromList xs = unsafeFromList Unknown xs
+fromList zs = Stream step zs
+  where
+    step (x:xs) = return (Yield x xs)
+    step []     = return Done
 
--- | Convert the first @n@ elements of a list to a 'Stream'
+-- | Convert the first @n@ elements of a list to a 'Bundle'
 fromListN :: Monad m => Int -> [a] -> Stream m a
-{-# INLINE_STREAM fromListN #-}
-fromListN n xs = Stream step (xs,n) (Max (delay_inline max n 0))
+{-# INLINE_FUSED fromListN #-}
+fromListN m zs = Stream step (zs,m)
   where
     {-# INLINE_INNER step #-}
-    step (xs,n) | n <= 0 = return Done
+    step (_, n) | n <= 0 = return Done
     step (x:xs,n)        = return (Yield x (xs,n-1))
-    step ([],n)          = return Done
+    step ([],_)          = return Done
 
--- | Convert a list to a 'Stream' with the given 'Size' hint. 
-unsafeFromList :: Monad m => Size -> [a] -> Stream m a
-{-# INLINE_STREAM unsafeFromList #-}
-unsafeFromList sz xs = Stream step xs sz
+{-
+fromVector :: (Monad m, Vector v a) => v a -> Stream m a
+{-# INLINE_FUSED fromVector #-}
+fromVector v = v `seq` n `seq` Stream (Unf step 0)
+                                      (Unf vstep True)
+                                      (Just v)
+                                      (Exact n)
   where
-    step (x:xs) = return (Yield x xs)
-    step []     = return Done
+    n = basicLength v
+
+    {-# INLINE step #-}
+    step i | i >= n = return Done
+           | otherwise = case basicUnsafeIndexM v i of
+                           Box x -> return $ Yield x (i+1)
+
+
+    {-# INLINE vstep #-}
+    vstep True  = return (Yield (Chunk (basicLength v) (\mv -> basicUnsafeCopy mv v)) False)
+    vstep False = return Done
+
+fromVectors :: forall m a. (Monad m, Vector v a) => [v a] -> Stream m a
+{-# INLINE_FUSED fromVectors #-}
+fromVectors vs = Stream (Unf pstep (Left vs))
+                        (Unf vstep vs)
+                        Nothing
+                        (Exact n)
+  where
+    n = List.foldl' (\k v -> k + basicLength v) 0 vs
+
+    pstep (Left []) = return Done
+    pstep (Left (v:vs)) = basicLength v `seq` return (Skip (Right (v,0,vs)))
+
+    pstep (Right (v,i,vs))
+      | i >= basicLength v = return $ Skip (Left vs)
+      | otherwise          = case basicUnsafeIndexM v i of
+                               Box x -> return $ Yield x (Right (v,i+1,vs))
+
+    -- FIXME: work around bug in GHC 7.6.1
+    vstep :: [v a] -> m (Step [v a] (Chunk v a))
+    vstep [] = return Done
+    vstep (v:vs) = return $ Yield (Chunk (basicLength v)
+                                         (\mv -> INTERNAL_CHECK(check) "concatVectors" "length mismatch"
+                                                                       (M.basicLength mv == basicLength v)
+                                                 $ basicUnsafeCopy mv v)) vs
+
+
+concatVectors :: (Monad m, Vector v a) => Stream m (v a) -> Stream m a
+{-# INLINE_FUSED concatVectors #-}
+concatVectors (Stream step s}
+  = Stream (Unf pstep (Left s))
+           (Unf vstep s)
+           Nothing
+           Unknown
+  where
+    pstep (Left s) = do
+      r <- step s
+      case r of
+        Yield v s' -> basicLength v `seq` return (Skip (Right (v,0,s')))
+        Skip    s' -> return (Skip (Left s'))
+        Done       -> return Done
+
+    pstep (Right (v,i,s))
+      | i >= basicLength v = return (Skip (Left s))
+      | otherwise          = case basicUnsafeIndexM v i of
+                               Box x -> return (Yield x (Right (v,i+1,s)))
+
+
+    vstep s = do
+      r <- step s
+      case r of
+        Yield v s' -> return (Yield (Chunk (basicLength v)
+                                           (\mv -> INTERNAL_CHECK(check) "concatVectors" "length mismatch"
+                                                                          (M.basicLength mv == basicLength v)
+                                                   $ basicUnsafeCopy mv v)) s')
+        Skip    s' -> return (Skip s')
+        Done       -> return Done
+
+reVector :: Monad m => Stream m a -> Stream m a
+{-# INLINE_FUSED reVector #-}
+reVector (Stream step s, sSize = n} = Stream step s n
+
+{-# RULES
+
+"reVector [Vector]"
+  reVector = id
+
+"reVector/reVector [Vector]" forall s.
+  reVector (reVector s) = s   #-}
+
+
+-}
 
diff --git a/Data/Vector/Fusion/Stream/Size.hs b/Data/Vector/Fusion/Stream/Size.hs
deleted file mode 100644
--- a/Data/Vector/Fusion/Stream/Size.hs
+++ /dev/null
@@ -1,87 +0,0 @@
--- |
--- Module      : Data.Vector.Fusion.Stream.Size
--- Copyright   : (c) Roman Leshchinskiy 2008-2010
--- License     : BSD-style
---
--- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
--- Stability   : experimental
--- Portability : portable
--- 
--- Size hints for streams.
---
-
-module Data.Vector.Fusion.Stream.Size (
-  Size(..), smaller, larger, toMax, upperBound
-) where
-
-import Data.Vector.Fusion.Util ( delay_inline )
-
--- | Size hint
-data Size = Exact Int          -- ^ Exact size
-          | Max   Int          -- ^ Upper bound on the size
-          | Unknown            -- ^ Unknown size
-        deriving( Eq, Show )
-
-instance Num Size where
-  Exact m + Exact n = Exact (m+n)
-  Exact m + Max   n = Max   (m+n)
-
-  Max   m + Exact n = Max   (m+n)
-  Max   m + Max   n = Max   (m+n)
-
-  _       + _       = Unknown
-
-
-  Exact m - Exact n = Exact (m-n)
-  Exact m - Max   n = Max   m
-
-  Max   m - Exact n = Max   (m-n)
-  Max   m - Max   n = Max   m
-  Max   m - Unknown = Max   m
-
-  _       - _       = Unknown
-
-
-  fromInteger n     = Exact (fromInteger n)
-
--- | Minimum of two size hints
-smaller :: Size -> Size -> Size
-{-# INLINE smaller #-}
-smaller (Exact m) (Exact n) = Exact (delay_inline min m n)
-smaller (Exact m) (Max   n) = Max   (delay_inline min m n)
-smaller (Exact m) Unknown   = Max   m
-smaller (Max   m) (Exact n) = Max   (delay_inline min m n)
-smaller (Max   m) (Max   n) = Max   (delay_inline min m n)
-smaller (Max   m) Unknown   = Max   m
-smaller Unknown   (Exact n) = Max   n
-smaller Unknown   (Max   n) = Max   n
-smaller Unknown   Unknown   = Unknown
-
--- | Maximum of two size hints
-larger :: Size -> Size -> Size
-{-# INLINE larger #-}
-larger (Exact m) (Exact n)             = Exact (delay_inline max m n)
-larger (Exact m) (Max   n) | m >= n    = Exact m
-                           | otherwise = Max   n
-larger (Max   m) (Exact n) | n >= m    = Exact n
-                           | otherwise = Max   m
-larger (Max   m) (Max   n)             = Max   (delay_inline max m n)
-larger _         _                     = Unknown
-
--- | Convert a size hint to an upper bound
-toMax :: Size -> Size
-toMax (Exact n) = Max n
-toMax (Max   n) = Max n
-toMax Unknown   = Unknown
-
--- | Compute the minimum size from a size hint
-lowerBound :: Size -> Int
-lowerBound (Exact n) = n
-lowerBound _         = 0
-
--- | Compute the maximum size from a size hint if possible
-upperBound :: Size -> Maybe Int
-upperBound (Exact n) = Just n
-upperBound (Max   n) = Just n
-upperBound Unknown   = Nothing
-
diff --git a/Data/Vector/Fusion/Util.hs b/Data/Vector/Fusion/Util.hs
--- a/Data/Vector/Fusion/Util.hs
+++ b/Data/Vector/Fusion/Util.hs
@@ -6,7 +6,7 @@
 -- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
 -- Stability   : experimental
 -- Portability : portable
--- 
+--
 -- Fusion-related utility types
 --
 
@@ -16,7 +16,7 @@
   delay_inline, delayed_min
 ) where
 
-import Control.Applicative
+import Control.Applicative (Applicative(..))
 
 -- | Identity monad
 newtype Id a = Id { unId :: a }
diff --git a/Data/Vector/Generic.hs b/Data/Vector/Generic.hs
--- a/Data/Vector/Generic.hs
+++ b/Data/Vector/Generic.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE Rank2Types, MultiParamTypeClasses, FlexibleContexts,
+{-# LANGUAGE CPP, Rank2Types, MultiParamTypeClasses, FlexibleContexts,
              TypeFamilies, ScopedTypeVariables, BangPatterns #-}
 -- |
 -- Module      : Data.Vector.Generic
@@ -8,7 +8,7 @@
 -- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
 -- Stability   : experimental
 -- Portability : non-portable
--- 
+--
 -- Generic interface to pure vectors.
 --
 
@@ -64,7 +64,7 @@
   accum, accumulate, accumulate_,
   unsafeAccum, unsafeAccumulate, unsafeAccumulate_,
 
-  -- ** Permutations 
+  -- ** Permutations
   reverse, backpermute, unsafeBackpermute,
 
   -- ** Safe destructive updates
@@ -79,7 +79,7 @@
   map, imap, concatMap,
 
   -- ** Monadic mapping
-  mapM, mapM_, forM, forM_,
+  mapM, imapM, mapM_, imapM_, forM, forM_,
 
   -- ** Zipping
   zipWith, zipWith3, zipWith4, zipWith5, zipWith6,
@@ -87,7 +87,7 @@
   zip, zip3, zip4, zip5, zip6,
 
   -- ** Monadic zipping
-  zipWithM, zipWithM_,
+  zipWithM, izipWithM, zipWithM_, izipWithM_,
 
   -- ** Unzipping
   unzip, unzip3, unzip4, unzip5, unzip6,
@@ -115,8 +115,9 @@
   minIndex, minIndexBy, maxIndex, maxIndexBy,
 
   -- ** Monadic folds
-  foldM, foldM', fold1M, fold1M',
-  foldM_, foldM'_, fold1M_, fold1M'_,
+  foldM, ifoldM, foldM', ifoldM',
+  fold1M, fold1M', foldM_, ifoldM_,
+  foldM'_, ifoldM'_, fold1M_, fold1M'_,
 
   -- ** Monadic sequencing
   sequence, sequence_,
@@ -142,7 +143,7 @@
 
   -- * Fusion support
 
-  -- ** Conversion to/from Streams
+  -- ** Conversion to/from Bundles
   stream, unstream, streamR, unstreamR,
 
   -- ** Recycling support
@@ -162,22 +163,21 @@
 
 import           Data.Vector.Generic.Base
 
-import           Data.Vector.Generic.Mutable ( MVector )
 import qualified Data.Vector.Generic.Mutable as M
 
 import qualified Data.Vector.Generic.New as New
 import           Data.Vector.Generic.New ( New )
 
-import qualified Data.Vector.Fusion.Stream as Stream
-import           Data.Vector.Fusion.Stream ( Stream, MStream, Step(..), inplace, liftStream )
-import qualified Data.Vector.Fusion.Stream.Monadic as MStream
-import           Data.Vector.Fusion.Stream.Size
+import qualified Data.Vector.Fusion.Bundle as Bundle
+import           Data.Vector.Fusion.Bundle ( Bundle, MBundle, lift, inplace )
+import qualified Data.Vector.Fusion.Bundle.Monadic as MBundle
+import           Data.Vector.Fusion.Stream.Monadic ( Stream )
+import qualified Data.Vector.Fusion.Stream.Monadic as S
+import           Data.Vector.Fusion.Bundle.Size
 import           Data.Vector.Fusion.Util
 
 import Control.Monad.ST ( ST, runST )
 import Control.Monad.Primitive
-import qualified Control.Monad as Monad
-import qualified Data.List as List
 import Prelude hiding ( length, null,
                         replicate, (++), concat,
                         head, last,
@@ -217,27 +217,13 @@
 
 -- | /O(1)/ Yield the length of the vector.
 length :: Vector v a => v a -> Int
-{-# INLINE_STREAM length #-}
-length v = basicLength v
-
-{-# RULES
-
-"length/unstream [Vector]" forall s.
-  length (new (New.unstream s)) = Stream.length s
-
-  #-}
+{-# INLINE length #-}
+length = Bundle.length . stream
 
 -- | /O(1)/ Test whether a vector if empty
 null :: Vector v a => v a -> Bool
-{-# INLINE_STREAM null #-}
-null v = basicLength v == 0
-
-{-# RULES
-
-"null/unstream [Vector]" forall s.
-  null (new (New.unstream s)) = Stream.null s
-
-  #-}
+{-# INLINE null #-}
+null = Bundle.null . stream
 
 -- Indexing
 -- --------
@@ -245,68 +231,68 @@
 infixl 9 !
 -- | O(1) Indexing
 (!) :: Vector v a => v a -> Int -> a
-{-# INLINE_STREAM (!) #-}
+{-# INLINE_FUSED (!) #-}
 (!) v i = BOUNDS_CHECK(checkIndex) "(!)" i (length v)
         $ unId (basicUnsafeIndexM v i)
 
 infixl 9 !?
 -- | O(1) Safe indexing
 (!?) :: Vector v a => v a -> Int -> Maybe a
-{-# INLINE_STREAM (!?) #-}
+{-# INLINE_FUSED (!?) #-}
 v !? i | i < 0 || i >= length v = Nothing
        | otherwise              = Just $ unsafeIndex v i
 
 -- | /O(1)/ First element
 head :: Vector v a => v a -> a
-{-# INLINE_STREAM head #-}
+{-# INLINE_FUSED head #-}
 head v = v ! 0
 
 -- | /O(1)/ Last element
 last :: Vector v a => v a -> a
-{-# INLINE_STREAM last #-}
+{-# INLINE_FUSED last #-}
 last v = v ! (length v - 1)
 
 -- | /O(1)/ Unsafe indexing without bounds checking
 unsafeIndex :: Vector v a => v a -> Int -> a
-{-# INLINE_STREAM unsafeIndex #-}
+{-# INLINE_FUSED unsafeIndex #-}
 unsafeIndex v i = UNSAFE_CHECK(checkIndex) "unsafeIndex" i (length v)
                 $ unId (basicUnsafeIndexM v i)
 
 -- | /O(1)/ First element without checking if the vector is empty
 unsafeHead :: Vector v a => v a -> a
-{-# INLINE_STREAM unsafeHead #-}
+{-# INLINE_FUSED unsafeHead #-}
 unsafeHead v = unsafeIndex v 0
 
 -- | /O(1)/ Last element without checking if the vector is empty
 unsafeLast :: Vector v a => v a -> a
-{-# INLINE_STREAM unsafeLast #-}
+{-# INLINE_FUSED unsafeLast #-}
 unsafeLast v = unsafeIndex v (length v - 1)
 
 {-# RULES
 
 "(!)/unstream [Vector]" forall i s.
-  new (New.unstream s) ! i = s Stream.!! i
+  new (New.unstream s) ! i = s Bundle.!! i
 
 "(!?)/unstream [Vector]" forall i s.
-  new (New.unstream s) !? i = s Stream.!? i
+  new (New.unstream s) !? i = s Bundle.!? i
 
 "head/unstream [Vector]" forall s.
-  head (new (New.unstream s)) = Stream.head s
+  head (new (New.unstream s)) = Bundle.head s
 
 "last/unstream [Vector]" forall s.
-  last (new (New.unstream s)) = Stream.last s
+  last (new (New.unstream s)) = Bundle.last s
 
 "unsafeIndex/unstream [Vector]" forall i s.
-  unsafeIndex (new (New.unstream s)) i = s Stream.!! i
+  unsafeIndex (new (New.unstream s)) i = s Bundle.!! i
 
 "unsafeHead/unstream [Vector]" forall s.
-  unsafeHead (new (New.unstream s)) = Stream.head s
+  unsafeHead (new (New.unstream s)) = Bundle.head s
 
 "unsafeLast/unstream [Vector]" forall s.
-  unsafeLast (new (New.unstream s)) = Stream.last s
+  unsafeLast (new (New.unstream s)) = Bundle.last s  #-}
 
- #-}
 
+
 -- Monadic indexing
 -- ----------------
 
@@ -330,63 +316,63 @@
 -- elements) is evaluated eagerly.
 --
 indexM :: (Vector v a, Monad m) => v a -> Int -> m a
-{-# INLINE_STREAM indexM #-}
+{-# INLINE_FUSED indexM #-}
 indexM v i = BOUNDS_CHECK(checkIndex) "indexM" i (length v)
            $ basicUnsafeIndexM v i
 
 -- | /O(1)/ First element of a vector in a monad. See 'indexM' for an
 -- explanation of why this is useful.
 headM :: (Vector v a, Monad m) => v a -> m a
-{-# INLINE_STREAM headM #-}
+{-# INLINE_FUSED headM #-}
 headM v = indexM v 0
 
 -- | /O(1)/ Last element of a vector in a monad. See 'indexM' for an
 -- explanation of why this is useful.
 lastM :: (Vector v a, Monad m) => v a -> m a
-{-# INLINE_STREAM lastM #-}
+{-# INLINE_FUSED lastM #-}
 lastM v = indexM v (length v - 1)
 
 -- | /O(1)/ Indexing in a monad without bounds checks. See 'indexM' for an
 -- explanation of why this is useful.
 unsafeIndexM :: (Vector v a, Monad m) => v a -> Int -> m a
-{-# INLINE_STREAM unsafeIndexM #-}
+{-# INLINE_FUSED unsafeIndexM #-}
 unsafeIndexM v i = UNSAFE_CHECK(checkIndex) "unsafeIndexM" i (length v)
                  $ basicUnsafeIndexM v i
 
 -- | /O(1)/ First element in a monad without checking for empty vectors.
 -- See 'indexM' for an explanation of why this is useful.
 unsafeHeadM :: (Vector v a, Monad m) => v a -> m a
-{-# INLINE_STREAM unsafeHeadM #-}
+{-# INLINE_FUSED unsafeHeadM #-}
 unsafeHeadM v = unsafeIndexM v 0
 
 -- | /O(1)/ Last element in a monad without checking for empty vectors.
 -- See 'indexM' for an explanation of why this is useful.
 unsafeLastM :: (Vector v a, Monad m) => v a -> m a
-{-# INLINE_STREAM unsafeLastM #-}
+{-# INLINE_FUSED unsafeLastM #-}
 unsafeLastM v = unsafeIndexM v (length v - 1)
 
 {-# RULES
 
 "indexM/unstream [Vector]" forall s i.
-  indexM (new (New.unstream s)) i = liftStream s MStream.!! i
+  indexM (new (New.unstream s)) i = lift s MBundle.!! i
 
 "headM/unstream [Vector]" forall s.
-  headM (new (New.unstream s)) = MStream.head (liftStream s)
+  headM (new (New.unstream s)) = MBundle.head (lift s)
 
 "lastM/unstream [Vector]" forall s.
-  lastM (new (New.unstream s)) = MStream.last (liftStream s)
+  lastM (new (New.unstream s)) = MBundle.last (lift s)
 
 "unsafeIndexM/unstream [Vector]" forall s i.
-  unsafeIndexM (new (New.unstream s)) i = liftStream s MStream.!! i
+  unsafeIndexM (new (New.unstream s)) i = lift s MBundle.!! i
 
 "unsafeHeadM/unstream [Vector]" forall s.
-  unsafeHeadM (new (New.unstream s)) = MStream.head (liftStream s)
+  unsafeHeadM (new (New.unstream s)) = MBundle.head (lift s)
 
 "unsafeLastM/unstream [Vector]" forall s.
-  unsafeLastM (new (New.unstream s)) = MStream.last (liftStream s)
+  unsafeLastM (new (New.unstream s)) = MBundle.last (lift s)   #-}
 
-  #-}
 
+
 -- Extracting subvectors (slicing)
 -- -------------------------------
 
@@ -396,33 +382,33 @@
                     -> Int   -- ^ @n@ length
                     -> v a
                     -> v a
-{-# INLINE_STREAM slice #-}
+{-# INLINE_FUSED slice #-}
 slice i n v = BOUNDS_CHECK(checkSlice) "slice" i n (length v)
             $ basicUnsafeSlice i n v
 
 -- | /O(1)/ Yield all but the last element without copying. The vector may not
 -- be empty.
 init :: Vector v a => v a -> v a
-{-# INLINE_STREAM init #-}
+{-# INLINE_FUSED init #-}
 init v = slice 0 (length v - 1) v
 
 -- | /O(1)/ Yield all but the first element without copying. The vector may not
 -- be empty.
 tail :: Vector v a => v a -> v a
-{-# INLINE_STREAM tail #-}
+{-# INLINE_FUSED tail #-}
 tail v = slice 1 (length v - 1) v
 
 -- | /O(1)/ Yield the first @n@ elements without copying. The vector may
 -- contain less than @n@ elements in which case it is returned unchanged.
 take :: Vector v a => Int -> v a -> v a
-{-# INLINE_STREAM take #-}
+{-# INLINE_FUSED take #-}
 take n v = unsafeSlice 0 (delay_inline min n' (length v)) v
   where n' = max n 0
 
 -- | /O(1)/ Yield all but the first @n@ elements without copying. The vector may
 -- contain less than @n@ elements in which case an empty vector is returned.
 drop :: Vector v a => Int -> v a -> v a
-{-# INLINE_STREAM drop #-}
+{-# INLINE_FUSED drop #-}
 drop n v = unsafeSlice (delay_inline min n' len)
                        (delay_inline max 0 (len - n')) v
   where n' = max n 0
@@ -432,7 +418,7 @@
 --
 -- Note that @'splitAt' n v@ is equivalent to @('take' n v, 'drop' n v)@
 -- but slightly more efficient.
-{-# INLINE_STREAM splitAt #-}
+{-# INLINE_FUSED splitAt #-}
 splitAt :: Vector v a => Int -> v a -> (v a, v a)
 splitAt n v = ( unsafeSlice 0 m v
               , unsafeSlice m (delay_inline max 0 (len - n')) v
@@ -448,20 +434,20 @@
                           -> Int   -- ^ @n@ length
                           -> v a
                           -> v a
-{-# INLINE_STREAM unsafeSlice #-}
+{-# INLINE_FUSED unsafeSlice #-}
 unsafeSlice i n v = UNSAFE_CHECK(checkSlice) "unsafeSlice" i n (length v)
                   $ basicUnsafeSlice i n v
 
 -- | /O(1)/ Yield all but the last element without copying. The vector may not
 -- be empty but this is not checked.
 unsafeInit :: Vector v a => v a -> v a
-{-# INLINE_STREAM unsafeInit #-}
+{-# INLINE_FUSED unsafeInit #-}
 unsafeInit v = unsafeSlice 0 (length v - 1) v
 
 -- | /O(1)/ Yield all but the first element without copying. The vector may not
 -- be empty but this is not checked.
 unsafeTail :: Vector v a => v a -> v a
-{-# INLINE_STREAM unsafeTail #-}
+{-# INLINE_FUSED unsafeTail #-}
 unsafeTail v = unsafeSlice 1 (length v - 1) v
 
 -- | /O(1)/ Yield the first @n@ elements without copying. The vector must
@@ -500,41 +486,41 @@
   unsafeInit (new p) = new (New.unsafeInit p)
 
 "unsafeTail/new [Vector]" forall p.
-  unsafeTail (new p) = new (New.unsafeTail p)
+  unsafeTail (new p) = new (New.unsafeTail p)   #-}
 
-  #-}
 
+
 -- Initialisation
 -- --------------
 
 -- | /O(1)/ Empty vector
 empty :: Vector v a => v a
 {-# INLINE empty #-}
-empty = unstream Stream.empty
+empty = unstream Bundle.empty
 
 -- | /O(1)/ Vector with exactly one element
 singleton :: forall v a. Vector v a => a -> v a
 {-# INLINE singleton #-}
 singleton x = elemseq (undefined :: v a) x
-            $ unstream (Stream.singleton x)
+            $ unstream (Bundle.singleton x)
 
 -- | /O(n)/ Vector of the given length with the same value in each position
 replicate :: forall v a. Vector v a => Int -> a -> v a
 {-# INLINE replicate #-}
 replicate n x = elemseq (undefined :: v a) x
               $ unstream
-              $ Stream.replicate n x
+              $ Bundle.replicate n x
 
 -- | /O(n)/ Construct a vector of the given length by applying the function to
 -- each index
 generate :: Vector v a => Int -> (Int -> a) -> v a
 {-# INLINE generate #-}
-generate n f = unstream (Stream.generate n f)
+generate n f = unstream (Bundle.generate n f)
 
 -- | /O(n)/ Apply function n times to value. Zeroth element is original value.
 iterateN :: Vector v a => Int -> (a -> a) -> a -> v a
 {-# INLINE iterateN #-}
-iterateN n f x = unstream (Stream.iterateN n f x)
+iterateN n f x = unstream (Bundle.iterateN n f x)
 
 -- Unfolding
 -- ---------
@@ -547,7 +533,7 @@
 -- >  = <10,9,8,7,6,5,4,3,2,1>
 unfoldr :: Vector v a => (b -> Maybe (a, b)) -> b -> v a
 {-# INLINE unfoldr #-}
-unfoldr f = unstream . Stream.unfoldr f
+unfoldr f = unstream . Bundle.unfoldr f
 
 -- | /O(n)/ Construct a vector with at most @n@ by repeatedly applying the
 -- generator function to the a seed. The generator function yields 'Just' the
@@ -556,7 +542,7 @@
 -- > unfoldrN 3 (\n -> Just (n,n-1)) 10 = <10,9,8>
 unfoldrN  :: Vector v a => Int -> (b -> Maybe (a, b)) -> b -> v a
 {-# INLINE unfoldrN #-}
-unfoldrN n f = unstream . Stream.unfoldrN n f
+unfoldrN n f = unstream . Bundle.unfoldrN n f
 
 -- | /O(n)/ Construct a vector with @n@ elements by repeatedly applying the
 -- generator function to the already constructed part of the vector.
@@ -584,7 +570,7 @@
                           v'' <- unsafeFreeze v'
                           fill v'' (i+1)
 
-    fill v i = return v
+    fill v _ = return v
 
 -- | /O(n)/ Construct a vector with @n@ elements from right to left by
 -- repeatedly applying the generator function to the already constructed part
@@ -613,7 +599,7 @@
                           v'' <- unsafeFreeze v'
                           fill v'' (i+1)
 
-    fill v i = return v
+    fill v _ = return v
 
 
 -- Enumeration
@@ -636,7 +622,7 @@
 enumFromStepN x y n = elemseq (undefined :: v a) x
                     $ elemseq (undefined :: v a) y
                     $ unstream
-                    $ Stream.enumFromStepN  x y n
+                    $ Bundle.enumFromStepN  x y n
 
 -- | /O(n)/ Enumerate values from @x@ to @y@.
 --
@@ -644,7 +630,7 @@
 -- 'enumFromN' instead.
 enumFromTo :: (Vector v a, Enum a) => a -> a -> v a
 {-# INLINE enumFromTo #-}
-enumFromTo x y = unstream (Stream.enumFromTo x y)
+enumFromTo x y = unstream (Bundle.enumFromTo x y)
 
 -- | /O(n)/ Enumerate values from @x@ to @y@ with a specific step @z@.
 --
@@ -652,7 +638,7 @@
 -- 'enumFromStepN' instead.
 enumFromThenTo :: (Vector v a, Enum a) => a -> a -> a -> v a
 {-# INLINE enumFromThenTo #-}
-enumFromThenTo x y z = unstream (Stream.enumFromThenTo x y z)
+enumFromThenTo x y z = unstream (Bundle.enumFromThenTo x y z)
 
 -- Concatenation
 -- -------------
@@ -662,7 +648,7 @@
 {-# INLINE cons #-}
 cons x v = elemseq (undefined :: v a) x
          $ unstream
-         $ Stream.cons x
+         $ Bundle.cons x
          $ stream v
 
 -- | /O(n)/ Append an element
@@ -670,31 +656,34 @@
 {-# INLINE snoc #-}
 snoc v x = elemseq (undefined :: v a) x
          $ unstream
-         $ Stream.snoc (stream v) x
+         $ Bundle.snoc (stream v) x
 
 infixr 5 ++
 -- | /O(m+n)/ Concatenate two vectors
 (++) :: Vector v a => v a -> v a -> v a
 {-# INLINE (++) #-}
-v ++ w = unstream (stream v Stream.++ stream w)
+v ++ w = unstream (stream v Bundle.++ stream w)
 
 -- | /O(n)/ Concatenate all vectors in the list
 concat :: Vector v a => [v a] -> v a
 {-# INLINE concat #-}
-concat vs = unstream (Stream.flatten mk step (Exact n) (Stream.fromList vs))
+concat = unstream . Bundle.fromVectors
+{-
+concat vs = unstream (Bundle.flatten mk step (Exact n) (Bundle.fromList vs))
   where
     n = List.foldl' (\k v -> k + length v) 0 vs
 
     {-# INLINE_INNER step #-}
     step (v,i,k)
       | i < k = case unsafeIndexM v i of
-                  Box x -> Stream.Yield x (v,i+1,k)
-      | otherwise = Stream.Done
+                  Box x -> Bundle.Yield x (v,i+1,k)
+      | otherwise = Bundle.Done
 
     {-# INLINE mk #-}
     mk v = let k = length v
            in
            k `seq` (v,0,k)
+-}
 
 -- Monadic initialisation
 -- ----------------------
@@ -703,13 +692,13 @@
 -- results in a vector.
 replicateM :: (Monad m, Vector v a) => Int -> m a -> m (v a)
 {-# INLINE replicateM #-}
-replicateM n m = unstreamM (MStream.replicateM n m)
+replicateM n m = unstreamM (MBundle.replicateM n m)
 
 -- | /O(n)/ Construct a vector of the given length by applying the monadic
 -- action to each index
 generateM :: (Monad m, Vector v a) => Int -> (Int -> m a) -> m (v a)
 {-# INLINE generateM #-}
-generateM n f = unstreamM (MStream.generateM n f)
+generateM n f = unstreamM (MBundle.generateM n f)
 
 -- | Execute the monadic action and freeze the resulting vector.
 --
@@ -736,7 +725,7 @@
 force :: Vector v a => v a -> v a
 -- FIXME: we probably ought to inline this later as the rules still might fire
 -- otherwise
-{-# INLINE_STREAM force #-}
+{-# INLINE_FUSED force #-}
 force v = new (clone v)
 
 -- Bulk updates
@@ -751,7 +740,7 @@
                    -> [(Int, a)] -- ^ list of index/value pairs (of length @n@)
                    -> v a
 {-# INLINE (//) #-}
-v // us = update_stream v (Stream.fromList us)
+v // us = update_stream v (Bundle.fromList us)
 
 -- | /O(m+n)/ For each pair @(i,a)@ from the vector of index/value pairs,
 -- replace the vector element at position @i@ by @a@.
@@ -783,16 +772,16 @@
         -> v a   -- ^ value vector (of length @n2@)
         -> v a
 {-# INLINE update_ #-}
-update_ v is w = update_stream v (Stream.zipWith (,) (stream is) (stream w))
+update_ v is w = update_stream v (Bundle.zipWith (,) (stream is) (stream w))
 
-update_stream :: Vector v a => v a -> Stream (Int,a) -> v a
+update_stream :: Vector v a => v a -> Bundle u (Int,a) -> v a
 {-# INLINE update_stream #-}
-update_stream = modifyWithStream M.update
+update_stream = modifyWithBundle M.update
 
 -- | Same as ('//') but without bounds checking.
 unsafeUpd :: Vector v a => v a -> [(Int, a)] -> v a
 {-# INLINE unsafeUpd #-}
-unsafeUpd v us = unsafeUpdate_stream v (Stream.fromList us)
+unsafeUpd v us = unsafeUpdate_stream v (Bundle.fromList us)
 
 -- | Same as 'update' but without bounds checking.
 unsafeUpdate :: (Vector v a, Vector v (Int, a)) => v a -> v (Int, a) -> v a
@@ -803,11 +792,11 @@
 unsafeUpdate_ :: (Vector v a, Vector v Int) => v a -> v Int -> v a -> v a
 {-# INLINE unsafeUpdate_ #-}
 unsafeUpdate_ v is w
-  = unsafeUpdate_stream v (Stream.zipWith (,) (stream is) (stream w))
+  = unsafeUpdate_stream v (Bundle.zipWith (,) (stream is) (stream w))
 
-unsafeUpdate_stream :: Vector v a => v a -> Stream (Int,a) -> v a
+unsafeUpdate_stream :: Vector v a => v a -> Bundle u (Int,a) -> v a
 {-# INLINE unsafeUpdate_stream #-}
-unsafeUpdate_stream = modifyWithStream M.unsafeUpdate
+unsafeUpdate_stream = modifyWithBundle M.unsafeUpdate
 
 -- Accumulations
 -- -------------
@@ -822,7 +811,7 @@
       -> [(Int,b)]     -- ^ list of index/value pairs (of length @n@)
       -> v a
 {-# INLINE accum #-}
-accum f v us = accum_stream f v (Stream.fromList us)
+accum f v us = accum_stream f v (Bundle.fromList us)
 
 -- | /O(m+n)/ For each pair @(i,b)@ from the vector of pairs, replace the vector
 -- element @a@ at position @i@ by @f a b@.
@@ -856,18 +845,18 @@
                 -> v b           -- ^ value vector (of length @n2@)
                 -> v a
 {-# INLINE accumulate_ #-}
-accumulate_ f v is xs = accum_stream f v (Stream.zipWith (,) (stream is)
+accumulate_ f v is xs = accum_stream f v (Bundle.zipWith (,) (stream is)
                                                              (stream xs))
-                                        
 
-accum_stream :: Vector v a => (a -> b -> a) -> v a -> Stream (Int,b) -> v a
+
+accum_stream :: Vector v a => (a -> b -> a) -> v a -> Bundle u (Int,b) -> v a
 {-# INLINE accum_stream #-}
-accum_stream f = modifyWithStream (M.accum f)
+accum_stream f = modifyWithBundle (M.accum f)
 
 -- | Same as 'accum' but without bounds checking.
 unsafeAccum :: Vector v a => (a -> b -> a) -> v a -> [(Int,b)] -> v a
 {-# INLINE unsafeAccum #-}
-unsafeAccum f v us = unsafeAccum_stream f v (Stream.fromList us)
+unsafeAccum f v us = unsafeAccum_stream f v (Bundle.fromList us)
 
 -- | Same as 'accumulate' but without bounds checking.
 unsafeAccumulate :: (Vector v a, Vector v (Int, b))
@@ -880,12 +869,12 @@
                 => (a -> b -> a) -> v a -> v Int -> v b -> v a
 {-# INLINE unsafeAccumulate_ #-}
 unsafeAccumulate_ f v is xs
-  = unsafeAccum_stream f v (Stream.zipWith (,) (stream is) (stream xs))
+  = unsafeAccum_stream f v (Bundle.zipWith (,) (stream is) (stream xs))
 
 unsafeAccum_stream
-  :: Vector v a => (a -> b -> a) -> v a -> Stream (Int,b) -> v a
+  :: Vector v a => (a -> b -> a) -> v a -> Bundle u (Int,b) -> v a
 {-# INLINE unsafeAccum_stream #-}
-unsafeAccum_stream f = modifyWithStream (M.unsafeAccum f)
+unsafeAccum_stream f = modifyWithBundle (M.unsafeAccum f)
 
 -- Permutations
 -- ------------
@@ -912,8 +901,8 @@
 backpermute v is = seq v
                  $ seq n
                  $ unstream
-                 $ Stream.unbox
-                 $ Stream.map index
+                 $ Bundle.unbox
+                 $ Bundle.map index
                  $ stream is
   where
     n = length v
@@ -930,8 +919,8 @@
 unsafeBackpermute v is = seq v
                        $ seq n
                        $ unstream
-                       $ Stream.unbox
-                       $ Stream.map index
+                       $ Bundle.unbox
+                       $ Bundle.map index
                        $ stream is
   where
     n = length v
@@ -958,11 +947,11 @@
 
 -- We have to make sure that this is strict in the stream but we can't seq on
 -- it while fusion is happening. Hence this ugliness.
-modifyWithStream :: Vector v a
-                 => (forall s. Mutable v s a -> Stream b -> ST s ())
-                 -> v a -> Stream b -> v a
-{-# INLINE modifyWithStream #-}
-modifyWithStream p v s = new (New.modifyWithStream p (clone v) s)
+modifyWithBundle :: Vector v a
+                 => (forall s. Mutable v s a -> Bundle u b -> ST s ())
+                 -> v a -> Bundle u b -> v a
+{-# INLINE modifyWithBundle #-}
+modifyWithBundle p v s = new (New.modifyWithBundle p (clone v) s)
 
 -- Indexing
 -- --------
@@ -970,7 +959,7 @@
 -- | /O(n)/ Pair each element in a vector with its index
 indexed :: (Vector v a, Vector v (Int,a)) => v a -> v (Int,a)
 {-# INLINE indexed #-}
-indexed = unstream . Stream.indexed . stream
+indexed = unstream . Bundle.indexed . stream
 
 -- Mapping
 -- -------
@@ -978,12 +967,12 @@
 -- | /O(n)/ Map a function over a vector
 map :: (Vector v a, Vector v b) => (a -> b) -> v a -> v b
 {-# INLINE map #-}
-map f = unstream . inplace (MStream.map f) . stream
+map f = unstream . inplace (S.map f) id . stream
 
 -- | /O(n)/ Apply a function to every element of a vector and its index
 imap :: (Vector v a, Vector v b) => (Int -> a -> b) -> v a -> v b
 {-# INLINE imap #-}
-imap f = unstream . inplace (MStream.map (uncurry f) . MStream.indexed)
+imap f = unstream . inplace (S.map (uncurry f) . S.indexed) id
                   . stream
 
 -- | Map a function over a vector and concatenate the results.
@@ -991,28 +980,36 @@
 {-# INLINE concatMap #-}
 -- NOTE: We can't fuse concatMap anyway so don't pretend we do.
 -- This seems to be slightly slower
--- concatMap f = concat . Stream.toList . Stream.map f . stream
+-- concatMap f = concat . Bundle.toList . Bundle.map f . stream
 
 -- Slowest
--- concatMap f = unstream . Stream.concatMap (stream . f) . stream
+-- concatMap f = unstream . Bundle.concatMap (stream . f) . stream
 
--- Seems to be fastest
+-- Used to be fastest
+{-
 concatMap f = unstream
-            . Stream.flatten mk step Unknown
+            . Bundle.flatten mk step Unknown
             . stream
   where
     {-# INLINE_INNER step #-}
     step (v,i,k)
       | i < k = case unsafeIndexM v i of
-                  Box x -> Stream.Yield x (v,i+1,k)
-      | otherwise = Stream.Done
+                  Box x -> Bundle.Yield x (v,i+1,k)
+      | otherwise = Bundle.Done
 
     {-# INLINE mk #-}
     mk x = let v = f x
                k = length v
            in
            k `seq` (v,0,k)
+-}
 
+-- This seems to be fastest now
+concatMap f = unstream
+            . Bundle.concatVectors
+            . Bundle.map f
+            . stream
+
 -- Monadic mapping
 -- ---------------
 
@@ -1020,14 +1017,26 @@
 -- vector of results
 mapM :: (Monad m, Vector v a, Vector v b) => (a -> m b) -> v a -> m (v b)
 {-# INLINE mapM #-}
-mapM f = unstreamM . Stream.mapM f . stream
+mapM f = unstreamM . Bundle.mapM f . stream
 
+-- | /O(n)/ Apply the monadic action to every element of a vector and its
+-- index, yielding a vector of results
+imapM :: (Monad m, Vector v a, Vector v b)
+      => (Int -> a -> m b) -> v a -> m (v b)
+imapM f = unstreamM . Bundle.mapM (uncurry f) . Bundle.indexed . stream
+
 -- | /O(n)/ Apply the monadic action to all elements of a vector and ignore the
 -- results
 mapM_ :: (Monad m, Vector v a) => (a -> m b) -> v a -> m ()
 {-# INLINE mapM_ #-}
-mapM_ f = Stream.mapM_ f . stream
+mapM_ f = Bundle.mapM_ f . stream
 
+-- | /O(n)/ Apply the monadic action to every element of a vector and its
+-- index, ignoring the results
+imapM_ :: (Monad m, Vector v a) => (Int -> a -> m b) -> v a -> m ()
+{-# INLINE imapM_ #-}
+imapM_ f = Bundle.mapM_ (uncurry f) . Bundle.indexed . stream
+
 -- | /O(n)/ Apply the monadic action to all elements of the vector, yielding a
 -- vector of results. Equvalent to @flip 'mapM'@.
 forM :: (Monad m, Vector v a, Vector v b) => v a -> (a -> m b) -> m (v b)
@@ -1047,21 +1056,21 @@
 zipWith :: (Vector v a, Vector v b, Vector v c)
         => (a -> b -> c) -> v a -> v b -> v c
 {-# INLINE zipWith #-}
-zipWith f xs ys = unstream (Stream.zipWith f (stream xs) (stream ys))
+zipWith f = \xs ys -> unstream (Bundle.zipWith f (stream xs) (stream ys))
 
 -- | Zip three vectors with the given function.
 zipWith3 :: (Vector v a, Vector v b, Vector v c, Vector v d)
          => (a -> b -> c -> d) -> v a -> v b -> v c -> v d
 {-# INLINE zipWith3 #-}
-zipWith3 f as bs cs = unstream (Stream.zipWith3 f (stream as)
+zipWith3 f = \as bs cs -> unstream (Bundle.zipWith3 f (stream as)
                                                   (stream bs)
                                                   (stream cs))
 
 zipWith4 :: (Vector v a, Vector v b, Vector v c, Vector v d, Vector v e)
          => (a -> b -> c -> d -> e) -> v a -> v b -> v c -> v d -> v e
 {-# INLINE zipWith4 #-}
-zipWith4 f as bs cs ds
-  = unstream (Stream.zipWith4 f (stream as)
+zipWith4 f = \as bs cs ds ->
+    unstream (Bundle.zipWith4 f (stream as)
                                 (stream bs)
                                 (stream cs)
                                 (stream ds))
@@ -1071,8 +1080,8 @@
          => (a -> b -> c -> d -> e -> f) -> v a -> v b -> v c -> v d -> v e
                                          -> v f
 {-# INLINE zipWith5 #-}
-zipWith5 f as bs cs ds es
-  = unstream (Stream.zipWith5 f (stream as)
+zipWith5 f = \as bs cs ds es ->
+    unstream (Bundle.zipWith5 f (stream as)
                                 (stream bs)
                                 (stream cs)
                                 (stream ds)
@@ -1083,8 +1092,8 @@
          => (a -> b -> c -> d -> e -> f -> g)
          -> v a -> v b -> v c -> v d -> v e -> v f -> v g
 {-# INLINE zipWith6 #-}
-zipWith6 f as bs cs ds es fs
-  = unstream (Stream.zipWith6 f (stream as)
+zipWith6 f = \as bs cs ds es fs ->
+    unstream (Bundle.zipWith6 f (stream as)
                                 (stream bs)
                                 (stream cs)
                                 (stream ds)
@@ -1096,23 +1105,23 @@
 izipWith :: (Vector v a, Vector v b, Vector v c)
         => (Int -> a -> b -> c) -> v a -> v b -> v c
 {-# INLINE izipWith #-}
-izipWith f xs ys = unstream
-                  (Stream.zipWith (uncurry f) (Stream.indexed (stream xs))
-                                                              (stream ys))
+izipWith f = \xs ys ->
+    unstream (Bundle.zipWith (uncurry f) (Bundle.indexed (stream xs))
+                                                         (stream ys))
 
 izipWith3 :: (Vector v a, Vector v b, Vector v c, Vector v d)
          => (Int -> a -> b -> c -> d) -> v a -> v b -> v c -> v d
 {-# INLINE izipWith3 #-}
-izipWith3 f as bs cs
-  = unstream (Stream.zipWith3 (uncurry f) (Stream.indexed (stream as))
+izipWith3 f = \as bs cs ->
+    unstream (Bundle.zipWith3 (uncurry f) (Bundle.indexed (stream as))
                                                           (stream bs)
                                                           (stream cs))
 
 izipWith4 :: (Vector v a, Vector v b, Vector v c, Vector v d, Vector v e)
          => (Int -> a -> b -> c -> d -> e) -> v a -> v b -> v c -> v d -> v e
 {-# INLINE izipWith4 #-}
-izipWith4 f as bs cs ds
-  = unstream (Stream.zipWith4 (uncurry f) (Stream.indexed (stream as))
+izipWith4 f = \as bs cs ds ->
+    unstream (Bundle.zipWith4 (uncurry f) (Bundle.indexed (stream as))
                                                           (stream bs)
                                                           (stream cs)
                                                           (stream ds))
@@ -1122,8 +1131,8 @@
          => (Int -> a -> b -> c -> d -> e -> f) -> v a -> v b -> v c -> v d
                                                 -> v e -> v f
 {-# INLINE izipWith5 #-}
-izipWith5 f as bs cs ds es
-  = unstream (Stream.zipWith5 (uncurry f) (Stream.indexed (stream as))
+izipWith5 f = \as bs cs ds es ->
+    unstream (Bundle.zipWith5 (uncurry f) (Bundle.indexed (stream as))
                                                           (stream bs)
                                                           (stream cs)
                                                           (stream ds)
@@ -1134,8 +1143,8 @@
          => (Int -> a -> b -> c -> d -> e -> f -> g)
          -> v a -> v b -> v c -> v d -> v e -> v f -> v g
 {-# INLINE izipWith6 #-}
-izipWith6 f as bs cs ds es fs
-  = unstream (Stream.zipWith6 (uncurry f) (Stream.indexed (stream as))
+izipWith6 f = \as bs cs ds es fs ->
+    unstream (Bundle.zipWith6 (uncurry f) (Bundle.indexed (stream as))
                                                           (stream bs)
                                                           (stream cs)
                                                           (stream ds)
@@ -1178,15 +1187,33 @@
          => (a -> b -> m c) -> v a -> v b -> m (v c)
 -- FIXME: specialise for ST and IO?
 {-# INLINE zipWithM #-}
-zipWithM f as bs = unstreamM $ Stream.zipWithM f (stream as) (stream bs)
+zipWithM f = \as bs -> unstreamM $ Bundle.zipWithM f (stream as) (stream bs)
 
+-- | /O(min(m,n))/ Zip the two vectors with a monadic action that also takes
+-- the element index and yield a vector of results
+izipWithM :: (Monad m, Vector v a, Vector v b, Vector v c)
+         => (Int -> a -> b -> m c) -> v a -> v b -> m (v c)
+{-# INLINE izipWithM #-}
+izipWithM m as bs = unstreamM . Bundle.zipWithM (uncurry m)
+                                (Bundle.indexed (stream as))
+                                $ stream bs
+
 -- | /O(min(m,n))/ Zip the two vectors with the monadic action and ignore the
 -- results
 zipWithM_ :: (Monad m, Vector v a, Vector v b)
           => (a -> b -> m c) -> v a -> v b -> m ()
 {-# INLINE zipWithM_ #-}
-zipWithM_ f as bs = Stream.zipWithM_ f (stream as) (stream bs)
+zipWithM_ f = \as bs -> Bundle.zipWithM_ f (stream as) (stream bs)
 
+-- | /O(min(m,n))/ Zip the two vectors with a monadic action that also takes
+-- the element index and ignore the results
+izipWithM_ :: (Monad m, Vector v a, Vector v b)
+          => (Int -> a -> b -> m c) -> v a -> v b -> m ()
+{-# INLINE izipWithM_ #-}
+izipWithM_ m as bs = Bundle.zipWithM_ (uncurry m)
+                      (Bundle.indexed (stream as))
+                      $ stream bs
+
 -- Unzipping
 -- ---------
 
@@ -1198,39 +1225,39 @@
 unzip3 :: (Vector v a, Vector v b, Vector v c, Vector v (a, b, c))
        => v (a, b, c) -> (v a, v b, v c)
 {-# INLINE unzip3 #-}
-unzip3 xs = (map (\(a, b, c) -> a) xs,
-             map (\(a, b, c) -> b) xs,
-             map (\(a, b, c) -> c) xs)
+unzip3 xs = (map (\(a, _, _) -> a) xs,
+             map (\(_, b, _) -> b) xs,
+             map (\(_, _, c) -> c) xs)
 
 unzip4 :: (Vector v a, Vector v b, Vector v c, Vector v d,
            Vector v (a, b, c, d))
        => v (a, b, c, d) -> (v a, v b, v c, v d)
 {-# INLINE unzip4 #-}
-unzip4 xs = (map (\(a, b, c, d) -> a) xs,
-             map (\(a, b, c, d) -> b) xs,
-             map (\(a, b, c, d) -> c) xs,
-             map (\(a, b, c, d) -> d) xs)
+unzip4 xs = (map (\(a, _, _, _) -> a) xs,
+             map (\(_, b, _, _) -> b) xs,
+             map (\(_, _, c, _) -> c) xs,
+             map (\(_, _, _, d) -> d) xs)
 
 unzip5 :: (Vector v a, Vector v b, Vector v c, Vector v d, Vector v e,
            Vector v (a, b, c, d, e))
        => v (a, b, c, d, e) -> (v a, v b, v c, v d, v e)
 {-# INLINE unzip5 #-}
-unzip5 xs = (map (\(a, b, c, d, e) -> a) xs,
-             map (\(a, b, c, d, e) -> b) xs,
-             map (\(a, b, c, d, e) -> c) xs,
-             map (\(a, b, c, d, e) -> d) xs,
-             map (\(a, b, c, d, e) -> e) xs)
+unzip5 xs = (map (\(a, _, _, _, _) -> a) xs,
+             map (\(_, b, _, _, _) -> b) xs,
+             map (\(_, _, c, _, _) -> c) xs,
+             map (\(_, _, _, d, _) -> d) xs,
+             map (\(_, _, _, _, e) -> e) xs)
 
 unzip6 :: (Vector v a, Vector v b, Vector v c, Vector v d, Vector v e,
            Vector v f, Vector v (a, b, c, d, e, f))
        => v (a, b, c, d, e, f) -> (v a, v b, v c, v d, v e, v f)
 {-# INLINE unzip6 #-}
-unzip6 xs = (map (\(a, b, c, d, e, f) -> a) xs,
-             map (\(a, b, c, d, e, f) -> b) xs,
-             map (\(a, b, c, d, e, f) -> c) xs,
-             map (\(a, b, c, d, e, f) -> d) xs,
-             map (\(a, b, c, d, e, f) -> e) xs,
-             map (\(a, b, c, d, e, f) -> f) xs)
+unzip6 xs = (map (\(a, _, _, _, _, _) -> a) xs,
+             map (\(_, b, _, _, _, _) -> b) xs,
+             map (\(_, _, c, _, _, _) -> c) xs,
+             map (\(_, _, _, d, _, _) -> d) xs,
+             map (\(_, _, _, _, e, _) -> e) xs,
+             map (\(_, _, _, _, _, f) -> f) xs)
 
 -- Filtering
 -- ---------
@@ -1238,33 +1265,32 @@
 -- | /O(n)/ Drop elements that do not satisfy the predicate
 filter :: Vector v a => (a -> Bool) -> v a -> v a
 {-# INLINE filter #-}
-filter f = unstream . inplace (MStream.filter f) . stream
+filter f = unstream . inplace (S.filter f) toMax . stream
 
 -- | /O(n)/ Drop elements that do not satisfy the predicate which is applied to
 -- values and their indices
 ifilter :: Vector v a => (Int -> a -> Bool) -> v a -> v a
 {-# INLINE ifilter #-}
 ifilter f = unstream
-          . inplace (MStream.map snd . MStream.filter (uncurry f)
-                                     . MStream.indexed)
+          . inplace (S.map snd . S.filter (uncurry f) . S.indexed) toMax
           . stream
 
 -- | /O(n)/ Drop elements that do not satisfy the monadic predicate
 filterM :: (Monad m, Vector v a) => (a -> m Bool) -> v a -> m (v a)
 {-# INLINE filterM #-}
-filterM f = unstreamM . Stream.filterM f . stream
+filterM f = unstreamM . Bundle.filterM f . stream
 
 -- | /O(n)/ Yield the longest prefix of elements satisfying the predicate
 -- without copying.
 takeWhile :: Vector v a => (a -> Bool) -> v a -> v a
 {-# INLINE takeWhile #-}
-takeWhile f = unstream . Stream.takeWhile f . stream
+takeWhile f = unstream . Bundle.takeWhile f . stream
 
 -- | /O(n)/ Drop the longest prefix of elements that satisfy the predicate
 -- without copying.
 dropWhile :: Vector v a => (a -> Bool) -> v a -> v a
 {-# INLINE dropWhile #-}
-dropWhile f = unstream . Stream.dropWhile f . stream
+dropWhile f = unstream . Bundle.dropWhile f . stream
 
 -- Parititioning
 -- -------------
@@ -1280,11 +1306,11 @@
 -- FIXME: Make this inplace-fusible (look at how stable_partition is
 -- implemented in C++)
 
-partition_stream :: Vector v a => (a -> Bool) -> Stream a -> (v a, v a)
-{-# INLINE_STREAM partition_stream #-}
+partition_stream :: Vector v a => (a -> Bool) -> Bundle u a -> (v a, v a)
+{-# INLINE_FUSED partition_stream #-}
 partition_stream f s = s `seq` runST (
   do
-    (mv1,mv2) <- M.partitionStream f s
+    (mv1,mv2) <- M.partitionBundle f s
     v1 <- unsafeFreeze mv1
     v2 <- unsafeFreeze mv2
     return (v1,v2))
@@ -1298,17 +1324,17 @@
 unstablePartition f = unstablePartition_stream f . stream
 
 unstablePartition_stream
-  :: Vector v a => (a -> Bool) -> Stream a -> (v a, v a)
-{-# INLINE_STREAM unstablePartition_stream #-}
+  :: Vector v a => (a -> Bool) -> Bundle u a -> (v a, v a)
+{-# INLINE_FUSED unstablePartition_stream #-}
 unstablePartition_stream f s = s `seq` runST (
   do
-    (mv1,mv2) <- M.unstablePartitionStream f s
+    (mv1,mv2) <- M.unstablePartitionBundle f s
     v1 <- unsafeFreeze mv1
     v2 <- unsafeFreeze mv2
     return (v1,v2))
 
 unstablePartition_new :: Vector v a => (a -> Bool) -> New v a -> (v a, v a)
-{-# INLINE_STREAM unstablePartition_new #-}
+{-# INLINE_FUSED unstablePartition_new #-}
 unstablePartition_new f (New.New p) = runST (
   do
     mv <- p
@@ -1320,11 +1346,11 @@
 
 "unstablePartition" forall f p.
   unstablePartition_stream f (stream (new p))
-    = unstablePartition_new f p
+    = unstablePartition_new f p   #-}
 
-  #-}
 
 
+
 -- FIXME: make span and break fusible
 
 -- | /O(n)/ Split the vector into the longest prefix of elements that satisfy
@@ -1340,8 +1366,8 @@
 break f xs = case findIndex f xs of
                Just i  -> (unsafeSlice 0 i xs, unsafeSlice i (length xs - i) xs)
                Nothing -> (xs, empty)
-    
 
+
 -- Searching
 -- ---------
 
@@ -1349,33 +1375,32 @@
 -- | /O(n)/ Check if the vector contains an element
 elem :: (Vector v a, Eq a) => a -> v a -> Bool
 {-# INLINE elem #-}
-elem x = Stream.elem x . stream
+elem x = Bundle.elem x . stream
 
 infix 4 `notElem`
 -- | /O(n)/ Check if the vector does not contain an element (inverse of 'elem')
 notElem :: (Vector v a, Eq a) => a -> v a -> Bool
 {-# INLINE notElem #-}
-notElem x = Stream.notElem x . stream
+notElem x = Bundle.notElem x . stream
 
 -- | /O(n)/ Yield 'Just' the first element matching the predicate or 'Nothing'
 -- if no such element exists.
 find :: Vector v a => (a -> Bool) -> v a -> Maybe a
 {-# INLINE find #-}
-find f = Stream.find f . stream
+find f = Bundle.find f . stream
 
 -- | /O(n)/ Yield 'Just' the index of the first element matching the predicate
 -- or 'Nothing' if no such element exists.
 findIndex :: Vector v a => (a -> Bool) -> v a -> Maybe Int
 {-# INLINE findIndex #-}
-findIndex f = Stream.findIndex f . stream
+findIndex f = Bundle.findIndex f . stream
 
 -- | /O(n)/ Yield the indices of elements satisfying the predicate in ascending
 -- order.
 findIndices :: (Vector v a, Vector v Int) => (a -> Bool) -> v a -> v Int
 {-# INLINE findIndices #-}
 findIndices f = unstream
-              . inplace (MStream.map fst . MStream.filter (f . snd)
-                                         . MStream.indexed)
+              . inplace (S.map fst . S.filter (f . snd) . S.indexed) toMax
               . stream
 
 -- | /O(n)/ Yield 'Just' the index of the first occurence of the given element or
@@ -1397,65 +1422,65 @@
 -- | /O(n)/ Left fold
 foldl :: Vector v b => (a -> b -> a) -> a -> v b -> a
 {-# INLINE foldl #-}
-foldl f z = Stream.foldl f z . stream
+foldl f z = Bundle.foldl f z . stream
 
 -- | /O(n)/ Left fold on non-empty vectors
 foldl1 :: Vector v a => (a -> a -> a) -> v a -> a
 {-# INLINE foldl1 #-}
-foldl1 f = Stream.foldl1 f . stream
+foldl1 f = Bundle.foldl1 f . stream
 
 -- | /O(n)/ Left fold with strict accumulator
 foldl' :: Vector v b => (a -> b -> a) -> a -> v b -> a
 {-# INLINE foldl' #-}
-foldl' f z = Stream.foldl' f z . stream
+foldl' f z = Bundle.foldl' f z . stream
 
 -- | /O(n)/ Left fold on non-empty vectors with strict accumulator
 foldl1' :: Vector v a => (a -> a -> a) -> v a -> a
 {-# INLINE foldl1' #-}
-foldl1' f = Stream.foldl1' f . stream
+foldl1' f = Bundle.foldl1' f . stream
 
 -- | /O(n)/ Right fold
 foldr :: Vector v a => (a -> b -> b) -> b -> v a -> b
 {-# INLINE foldr #-}
-foldr f z = Stream.foldr f z . stream
+foldr f z = Bundle.foldr f z . stream
 
 -- | /O(n)/ Right fold on non-empty vectors
 foldr1 :: Vector v a => (a -> a -> a) -> v a -> a
 {-# INLINE foldr1 #-}
-foldr1 f = Stream.foldr1 f . stream
+foldr1 f = Bundle.foldr1 f . stream
 
 -- | /O(n)/ Right fold with a strict accumulator
 foldr' :: Vector v a => (a -> b -> b) -> b -> v a -> b
 {-# INLINE foldr' #-}
-foldr' f z = Stream.foldl' (flip f) z . streamR
+foldr' f z = Bundle.foldl' (flip f) z . streamR
 
 -- | /O(n)/ Right fold on non-empty vectors with strict accumulator
 foldr1' :: Vector v a => (a -> a -> a) -> v a -> a
 {-# INLINE foldr1' #-}
-foldr1' f = Stream.foldl1' (flip f) . streamR
+foldr1' f = Bundle.foldl1' (flip f) . streamR
 
 -- | /O(n)/ Left fold (function applied to each element and its index)
 ifoldl :: Vector v b => (a -> Int -> b -> a) -> a -> v b -> a
 {-# INLINE ifoldl #-}
-ifoldl f z = Stream.foldl (uncurry . f) z . Stream.indexed . stream
+ifoldl f z = Bundle.foldl (uncurry . f) z . Bundle.indexed . stream
 
 -- | /O(n)/ Left fold with strict accumulator (function applied to each element
 -- and its index)
 ifoldl' :: Vector v b => (a -> Int -> b -> a) -> a -> v b -> a
 {-# INLINE ifoldl' #-}
-ifoldl' f z = Stream.foldl' (uncurry . f) z . Stream.indexed . stream
+ifoldl' f z = Bundle.foldl' (uncurry . f) z . Bundle.indexed . stream
 
 -- | /O(n)/ Right fold (function applied to each element and its index)
 ifoldr :: Vector v a => (Int -> a -> b -> b) -> b -> v a -> b
 {-# INLINE ifoldr #-}
-ifoldr f z = Stream.foldr (uncurry f) z . Stream.indexed . stream
+ifoldr f z = Bundle.foldr (uncurry f) z . Bundle.indexed . stream
 
 -- | /O(n)/ Right fold with strict accumulator (function applied to each
 -- element and its index)
 ifoldr' :: Vector v a => (Int -> a -> b -> b) -> b -> v a -> b
 {-# INLINE ifoldr' #-}
-ifoldr' f z xs = Stream.foldl' (flip (uncurry f)) z
-               $ Stream.indexedR (length xs) $ streamR xs
+ifoldr' f z xs = Bundle.foldl' (flip (uncurry f)) z
+               $ Bundle.indexedR (length xs) $ streamR xs
 
 -- Specialised folds
 -- -----------------
@@ -1463,47 +1488,47 @@
 -- | /O(n)/ Check if all elements satisfy the predicate.
 all :: Vector v a => (a -> Bool) -> v a -> Bool
 {-# INLINE all #-}
-all f = Stream.and . Stream.map f . stream
+all f = Bundle.and . Bundle.map f . stream
 
 -- | /O(n)/ Check if any element satisfies the predicate.
 any :: Vector v a => (a -> Bool) -> v a -> Bool
 {-# INLINE any #-}
-any f = Stream.or . Stream.map f . stream
+any f = Bundle.or . Bundle.map f . stream
 
 -- | /O(n)/ Check if all elements are 'True'
 and :: Vector v Bool => v Bool -> Bool
 {-# INLINE and #-}
-and = Stream.and . stream
+and = Bundle.and . stream
 
 -- | /O(n)/ Check if any element is 'True'
 or :: Vector v Bool => v Bool -> Bool
 {-# INLINE or #-}
-or = Stream.or . stream
+or = Bundle.or . stream
 
 -- | /O(n)/ Compute the sum of the elements
 sum :: (Vector v a, Num a) => v a -> a
 {-# INLINE sum #-}
-sum = Stream.foldl' (+) 0 . stream
+sum = Bundle.foldl' (+) 0 . stream
 
 -- | /O(n)/ Compute the produce of the elements
 product :: (Vector v a, Num a) => v a -> a
 {-# INLINE product #-}
-product = Stream.foldl' (*) 1 . stream
+product = Bundle.foldl' (*) 1 . stream
 
 -- | /O(n)/ Yield the maximum element of the vector. The vector may not be
 -- empty.
 maximum :: (Vector v a, Ord a) => v a -> a
 {-# INLINE maximum #-}
-maximum = Stream.foldl1' max . stream
+maximum = Bundle.foldl1' max . stream
 
 -- | /O(n)/ Yield the maximum element of the vector according to the given
 -- comparison function. The vector may not be empty.
 maximumBy :: Vector v a => (a -> a -> Ordering) -> v a -> a
 {-# INLINE maximumBy #-}
-maximumBy cmp = Stream.foldl1' maxBy . stream
+maximumBy cmpr = Bundle.foldl1' maxBy . stream
   where
     {-# INLINE maxBy #-}
-    maxBy x y = case cmp x y of
+    maxBy x y = case cmpr x y of
                   LT -> y
                   _  -> x
 
@@ -1511,16 +1536,16 @@
 -- empty.
 minimum :: (Vector v a, Ord a) => v a -> a
 {-# INLINE minimum #-}
-minimum = Stream.foldl1' min . stream
+minimum = Bundle.foldl1' min . stream
 
 -- | /O(n)/ Yield the minimum element of the vector according to the given
 -- comparison function. The vector may not be empty.
 minimumBy :: Vector v a => (a -> a -> Ordering) -> v a -> a
 {-# INLINE minimumBy #-}
-minimumBy cmp = Stream.foldl1' minBy . stream
+minimumBy cmpr = Bundle.foldl1' minBy . stream
   where
     {-# INLINE minBy #-}
-    minBy x y = case cmp x y of
+    minBy x y = case cmpr x y of
                   GT -> y
                   _  -> x
 
@@ -1534,10 +1559,10 @@
 -- the given comparison function. The vector may not be empty.
 maxIndexBy :: Vector v a => (a -> a -> Ordering) -> v a -> Int
 {-# INLINE maxIndexBy #-}
-maxIndexBy cmp = fst . Stream.foldl1' imax . Stream.indexed . stream
+maxIndexBy cmpr = fst . Bundle.foldl1' imax . Bundle.indexed . stream
   where
     imax (i,x) (j,y) = i `seq` j `seq`
-                       case cmp x y of
+                       case cmpr x y of
                          LT -> (j,y)
                          _  -> (i,x)
 
@@ -1551,10 +1576,10 @@
 -- the given comparison function. The vector may not be empty.
 minIndexBy :: Vector v a => (a -> a -> Ordering) -> v a -> Int
 {-# INLINE minIndexBy #-}
-minIndexBy cmp = fst . Stream.foldl1' imin . Stream.indexed . stream
+minIndexBy cmpr = fst . Bundle.foldl1' imin . Bundle.indexed . stream
   where
     imin (i,x) (j,y) = i `seq` j `seq`
-                       case cmp x y of
+                       case cmpr x y of
                          GT -> (j,y)
                          _  -> (i,x)
 
@@ -1564,22 +1589,33 @@
 -- | /O(n)/ Monadic fold
 foldM :: (Monad m, Vector v b) => (a -> b -> m a) -> a -> v b -> m a
 {-# INLINE foldM #-}
-foldM m z = Stream.foldM m z . stream
+foldM m z = Bundle.foldM m z . stream
 
+-- | /O(n)/ Monadic fold (action applied to each element and its index)
+ifoldM :: (Monad m, Vector v b) => (a -> Int -> b -> m a) -> a -> v b -> m a
+{-# INLINE ifoldM #-}
+ifoldM m z = Bundle.foldM (uncurry . m) z . Bundle.indexed . stream
+
 -- | /O(n)/ Monadic fold over non-empty vectors
 fold1M :: (Monad m, Vector v a) => (a -> a -> m a) -> v a -> m a
 {-# INLINE fold1M #-}
-fold1M m = Stream.fold1M m . stream
+fold1M m = Bundle.fold1M m . stream
 
 -- | /O(n)/ Monadic fold with strict accumulator
 foldM' :: (Monad m, Vector v b) => (a -> b -> m a) -> a -> v b -> m a
 {-# INLINE foldM' #-}
-foldM' m z = Stream.foldM' m z . stream
+foldM' m z = Bundle.foldM' m z . stream
 
+-- | /O(n)/ Monadic fold with strict accumulator (action applied to each
+-- element and its index)
+ifoldM' :: (Monad m, Vector v b) => (a -> Int -> b -> m a) -> a -> v b -> m a
+{-# INLINE ifoldM' #-}
+ifoldM' m z = Bundle.foldM' (uncurry . m) z . Bundle.indexed . stream
+
 -- | /O(n)/ Monadic fold over non-empty vectors with strict accumulator
 fold1M' :: (Monad m, Vector v a) => (a -> a -> m a) -> v a -> m a
 {-# INLINE fold1M' #-}
-fold1M' m = Stream.fold1M' m . stream
+fold1M' m = Bundle.fold1M' m . stream
 
 discard :: Monad m => m a -> m ()
 {-# INLINE discard #-}
@@ -1588,23 +1624,35 @@
 -- | /O(n)/ Monadic fold that discards the result
 foldM_ :: (Monad m, Vector v b) => (a -> b -> m a) -> a -> v b -> m ()
 {-# INLINE foldM_ #-}
-foldM_ m z = discard . Stream.foldM m z . stream
+foldM_ m z = discard . Bundle.foldM m z . stream
 
+-- | /O(n)/ Monadic fold that discards the result (action applied to
+-- each element and its index)
+ifoldM_ :: (Monad m, Vector v b) => (a -> Int -> b -> m a) -> a -> v b -> m ()
+{-# INLINE ifoldM_ #-}
+ifoldM_ m z = discard . Bundle.foldM (uncurry . m) z . Bundle.indexed . stream
+
 -- | /O(n)/ Monadic fold over non-empty vectors that discards the result
 fold1M_ :: (Monad m, Vector v a) => (a -> a -> m a) -> v a -> m ()
 {-# INLINE fold1M_ #-}
-fold1M_ m = discard . Stream.fold1M m . stream
+fold1M_ m = discard . Bundle.fold1M m . stream
 
 -- | /O(n)/ Monadic fold with strict accumulator that discards the result
 foldM'_ :: (Monad m, Vector v b) => (a -> b -> m a) -> a -> v b -> m ()
 {-# INLINE foldM'_ #-}
-foldM'_ m z = discard . Stream.foldM' m z . stream
+foldM'_ m z = discard . Bundle.foldM' m z . stream
 
+-- | /O(n)/ Monadic fold with strict accumulator that discards the result
+-- (action applied to each element and its index)
+ifoldM'_ :: (Monad m, Vector v b) => (a -> Int -> b -> m a) -> a -> v b -> m ()
+{-# INLINE ifoldM'_ #-}
+ifoldM'_ m z = discard . Bundle.foldM' (uncurry . m) z . Bundle.indexed . stream
+
 -- | /O(n)/ Monad fold over non-empty vectors with strict accumulator
 -- that discards the result
 fold1M'_ :: (Monad m, Vector v a) => (a -> a -> m a) -> v a -> m ()
 {-# INLINE fold1M'_ #-}
-fold1M'_ m = discard . Stream.fold1M' m . stream
+fold1M'_ m = discard . Bundle.fold1M' m . stream
 
 -- Monadic sequencing
 -- ------------------
@@ -1632,12 +1680,12 @@
 --
 prescanl :: (Vector v a, Vector v b) => (a -> b -> a) -> a -> v b -> v a
 {-# INLINE prescanl #-}
-prescanl f z = unstream . inplace (MStream.prescanl f z) . stream
+prescanl f z = unstream . inplace (S.prescanl f z) id . stream
 
 -- | /O(n)/ Prescan with strict accumulator
 prescanl' :: (Vector v a, Vector v b) => (a -> b -> a) -> a -> v b -> v a
 {-# INLINE prescanl' #-}
-prescanl' f z = unstream . inplace (MStream.prescanl' f z) . stream
+prescanl' f z = unstream . inplace (S.prescanl' f z) id . stream
 
 -- | /O(n)/ Scan
 --
@@ -1649,12 +1697,12 @@
 --
 postscanl :: (Vector v a, Vector v b) => (a -> b -> a) -> a -> v b -> v a
 {-# INLINE postscanl #-}
-postscanl f z = unstream . inplace (MStream.postscanl f z) . stream
+postscanl f z = unstream . inplace (S.postscanl f z) id . stream
 
 -- | /O(n)/ Scan with strict accumulator
 postscanl' :: (Vector v a, Vector v b) => (a -> b -> a) -> a -> v b -> v a
 {-# INLINE postscanl' #-}
-postscanl' f z = unstream . inplace (MStream.postscanl' f z) . stream
+postscanl' f z = unstream . inplace (S.postscanl' f z) id . stream
 
 -- | /O(n)/ Haskell-style scan
 --
@@ -1663,15 +1711,15 @@
 -- >         yi = f y(i-1) x(i-1)
 --
 -- Example: @scanl (+) 0 \<1,2,3,4\> = \<0,1,3,6,10\>@
--- 
+--
 scanl :: (Vector v a, Vector v b) => (a -> b -> a) -> a -> v b -> v a
 {-# INLINE scanl #-}
-scanl f z = unstream . Stream.scanl f z . stream
+scanl f z = unstream . Bundle.scanl f z . stream
 
 -- | /O(n)/ Haskell-style scan with strict accumulator
 scanl' :: (Vector v a, Vector v b) => (a -> b -> a) -> a -> v b -> v a
 {-# INLINE scanl' #-}
-scanl' f z = unstream . Stream.scanl' f z . stream
+scanl' f z = unstream . Bundle.scanl' f z . stream
 
 -- | /O(n)/ Scan over a non-empty vector
 --
@@ -1681,12 +1729,12 @@
 --
 scanl1 :: Vector v a => (a -> a -> a) -> v a -> v a
 {-# INLINE scanl1 #-}
-scanl1 f = unstream . inplace (MStream.scanl1 f) . stream
+scanl1 f = unstream . inplace (S.scanl1 f) id . stream
 
 -- | /O(n)/ Scan over a non-empty vector with a strict accumulator
 scanl1' :: Vector v a => (a -> a -> a) -> v a -> v a
 {-# INLINE scanl1' #-}
-scanl1' f = unstream . inplace (MStream.scanl1' f) . stream
+scanl1' f = unstream . inplace (S.scanl1' f) id . stream
 
 -- | /O(n)/ Right-to-left prescan
 --
@@ -1696,43 +1744,43 @@
 --
 prescanr :: (Vector v a, Vector v b) => (a -> b -> b) -> b -> v a -> v b
 {-# INLINE prescanr #-}
-prescanr f z = unstreamR . inplace (MStream.prescanl (flip f) z) . streamR
+prescanr f z = unstreamR . inplace (S.prescanl (flip f) z) id . streamR
 
 -- | /O(n)/ Right-to-left prescan with strict accumulator
 prescanr' :: (Vector v a, Vector v b) => (a -> b -> b) -> b -> v a -> v b
 {-# INLINE prescanr' #-}
-prescanr' f z = unstreamR . inplace (MStream.prescanl' (flip f) z) . streamR
+prescanr' f z = unstreamR . inplace (S.prescanl' (flip f) z) id . streamR
 
 -- | /O(n)/ Right-to-left scan
 postscanr :: (Vector v a, Vector v b) => (a -> b -> b) -> b -> v a -> v b
 {-# INLINE postscanr #-}
-postscanr f z = unstreamR . inplace (MStream.postscanl (flip f) z) . streamR
+postscanr f z = unstreamR . inplace (S.postscanl (flip f) z) id . streamR
 
 -- | /O(n)/ Right-to-left scan with strict accumulator
 postscanr' :: (Vector v a, Vector v b) => (a -> b -> b) -> b -> v a -> v b
 {-# INLINE postscanr' #-}
-postscanr' f z = unstreamR . inplace (MStream.postscanl' (flip f) z) . streamR
+postscanr' f z = unstreamR . inplace (S.postscanl' (flip f) z) id . streamR
 
 -- | /O(n)/ Right-to-left Haskell-style scan
 scanr :: (Vector v a, Vector v b) => (a -> b -> b) -> b -> v a -> v b
 {-# INLINE scanr #-}
-scanr f z = unstreamR . Stream.scanl (flip f) z . streamR
+scanr f z = unstreamR . Bundle.scanl (flip f) z . streamR
 
 -- | /O(n)/ Right-to-left Haskell-style scan with strict accumulator
 scanr' :: (Vector v a, Vector v b) => (a -> b -> b) -> b -> v a -> v b
 {-# INLINE scanr' #-}
-scanr' f z = unstreamR . Stream.scanl' (flip f) z . streamR
+scanr' f z = unstreamR . Bundle.scanl' (flip f) z . streamR
 
 -- | /O(n)/ Right-to-left scan over a non-empty vector
 scanr1 :: Vector v a => (a -> a -> a) -> v a -> v a
 {-# INLINE scanr1 #-}
-scanr1 f = unstreamR . inplace (MStream.scanl1 (flip f)) . streamR
+scanr1 f = unstreamR . inplace (S.scanl1 (flip f)) id . streamR
 
 -- | /O(n)/ Right-to-left scan over a non-empty vector with a strict
 -- accumulator
 scanr1' :: Vector v a => (a -> a -> a) -> v a -> v a
 {-# INLINE scanr1' #-}
-scanr1' f = unstreamR . inplace (MStream.scanl1' (flip f)) . streamR
+scanr1' f = unstreamR . inplace (S.scanl1' (flip f)) id . streamR
 
 -- Conversions - Lists
 -- ------------------------
@@ -1740,12 +1788,12 @@
 -- | /O(n)/ Convert a vector to a list
 toList :: Vector v a => v a -> [a]
 {-# INLINE toList #-}
-toList = Stream.toList . stream
+toList = Bundle.toList . stream
 
 -- | /O(n)/ Convert a list to a vector
 fromList :: Vector v a => [a] -> v a
 {-# INLINE fromList #-}
-fromList = unstream . Stream.fromList
+fromList = unstream . Bundle.fromList
 
 -- | /O(n)/ Convert the first @n@ elements of a list to a vector
 --
@@ -1754,7 +1802,7 @@
 -- @
 fromListN :: Vector v a => Int -> [a] -> v a
 {-# INLINE fromListN #-}
-fromListN n = unstream . Stream.fromListN n
+fromListN n = unstream . Bundle.fromListN n
 
 -- Conversions - Immutable vectors
 -- -------------------------------
@@ -1762,7 +1810,7 @@
 -- | /O(n)/ Convert different vector types
 convert :: (Vector v a, Vector w a) => v a -> w a
 {-# INLINE convert #-}
-convert = unstream . stream
+convert = unstream . Bundle.reVector . stream
 
 -- Conversions - Mutable vectors
 -- -----------------------------
@@ -1782,12 +1830,12 @@
 -- | /O(1)/ Unsafely convert an immutable vector to a mutable one without
 -- copying. The immutable vector may not be used after this operation.
 unsafeThaw :: (PrimMonad m, Vector v a) => v a -> m (Mutable v (PrimState m) a)
-{-# INLINE_STREAM unsafeThaw #-}
+{-# INLINE_FUSED unsafeThaw #-}
 unsafeThaw = basicUnsafeThaw
 
 -- | /O(n)/ Yield a mutable copy of the immutable vector.
 thaw :: (PrimMonad m, Vector v a) => v a -> m (Mutable v (PrimState m) a)
-{-# INLINE_STREAM thaw #-}
+{-# INLINE_FUSED thaw #-}
 thaw v = do
            mv <- M.unsafeNew (length v)
            unsafeCopy mv v
@@ -1799,15 +1847,15 @@
   unsafeThaw (new p) = New.runPrim p
 
 "thaw/new [Vector]" forall p.
-  thaw (new p) = New.runPrim p
+  thaw (new p) = New.runPrim p   #-}
 
-  #-}
 
+
 {-
 -- | /O(n)/ Yield a mutable vector containing copies of each vector in the
 -- list.
 thawMany :: (PrimMonad m, Vector v a) => [v a] -> m (Mutable v (PrimState m) a)
-{-# INLINE_STREAM thawMany #-}
+{-# INLINE_FUSED thawMany #-}
 -- FIXME: add rule for (stream (new (New.create (thawMany vs))))
 -- NOTE: We don't try to consume the list lazily as this wouldn't significantly
 -- change the space requirements anyway.
@@ -1844,13 +1892,16 @@
                                          (M.length dst == length src)
                    $ (dst `seq` src `seq` basicUnsafeCopy dst src)
 
--- Conversions to/from Streams
+-- Conversions to/from Bundles
 -- ---------------------------
 
--- | /O(1)/ Convert a vector to a 'Stream'
-stream :: Vector v a => v a -> Stream a
-{-# INLINE_STREAM stream #-}
-stream v = v `seq` n `seq` (Stream.unfoldr get 0 `Stream.sized` Exact n)
+-- | /O(1)/ Convert a vector to a 'Bundle'
+stream :: Vector v a => v a -> Bundle v a
+{-# INLINE_FUSED stream #-}
+stream v = Bundle.fromVector v
+
+{-
+stream v = v `seq` n `seq` (Bundle.unfoldr get 0 `Bundle.sized` Exact n)
   where
     n = length v
 
@@ -1859,9 +1910,10 @@
     {-# INLINE get #-}
     get i | i >= n    = Nothing
           | otherwise = case basicUnsafeIndexM v i of Box x -> Just (x, i+1)
+-}
 
--- | /O(n)/ Construct a vector from a 'Stream'
-unstream :: Vector v a => Stream a -> v a
+-- | /O(n)/ Construct a vector from a 'Bundle'
+unstream :: Vector v a => Bundle v a -> v a
 {-# INLINE unstream #-}
 unstream s = new (New.unstream s)
 
@@ -1877,19 +1929,19 @@
   clone (new p) = p
 
 "inplace [Vector]"
-  forall (f :: forall m. Monad m => MStream m a -> MStream m a) m.
-  New.unstream (inplace f (stream (new m))) = New.transform f m
+  forall (f :: forall m. Monad m => Stream m a -> Stream m a) g m.
+  New.unstream (inplace f g (stream (new m))) = New.transform f g m
 
 "uninplace [Vector]"
-  forall (f :: forall m. Monad m => MStream m a -> MStream m a) m.
-  stream (new (New.transform f m)) = inplace f (stream (new m))
+  forall (f :: forall m. Monad m => Stream m a -> Stream m a) g m.
+  stream (new (New.transform f g m)) = inplace f g (stream (new m))  #-}
 
- #-}
 
--- | /O(1)/ Convert a vector to a 'Stream', proceeding from right to left
-streamR :: Vector v a => v a -> Stream a
-{-# INLINE_STREAM streamR #-}
-streamR v = v `seq` n `seq` (Stream.unfoldr get n `Stream.sized` Exact n)
+
+-- | /O(1)/ Convert a vector to a 'Bundle', proceeding from right to left
+streamR :: Vector v a => v a -> Bundle u a
+{-# INLINE_FUSED streamR #-}
+streamR v = v `seq` n `seq` (Bundle.unfoldr get n `Bundle.sized` Exact n)
   where
     n = length v
 
@@ -1899,8 +1951,8 @@
             in
             case basicUnsafeIndexM v i' of Box x -> Just (x, i')
 
--- | /O(n)/ Construct a vector from a 'Stream', proceeding from right to left
-unstreamR :: Vector v a => Stream a -> v a
+-- | /O(n)/ Construct a vector from a 'Bundle', proceeding from right to left
+unstreamR :: Vector v a => Bundle v a -> v a
 {-# INLINE unstreamR #-}
 unstreamR s = new (New.unstreamR s)
 
@@ -1919,54 +1971,54 @@
   New.unstreamR (stream (new p)) = New.modify M.reverse p
 
 "inplace right [Vector]"
-  forall (f :: forall m. Monad m => MStream m a -> MStream m a) m.
-  New.unstreamR (inplace f (streamR (new m))) = New.transformR f m
+  forall (f :: forall m. Monad m => Stream m a -> Stream m a) g m.
+  New.unstreamR (inplace f g (streamR (new m))) = New.transformR f g m
 
 "uninplace right [Vector]"
-  forall (f :: forall m. Monad m => MStream m a -> MStream m a) m.
-  streamR (new (New.transformR f m)) = inplace f (streamR (new m))
+  forall (f :: forall m. Monad m => Stream m a -> Stream m a) g m.
+  streamR (new (New.transformR f g m)) = inplace f g (streamR (new m))  #-}
 
- #-}
 
-unstreamM :: (Monad m, Vector v a) => MStream m a -> m (v a)
-{-# INLINE_STREAM unstreamM #-}
+
+unstreamM :: (Monad m, Vector v a) => MBundle m u a -> m (v a)
+{-# INLINE_FUSED unstreamM #-}
 unstreamM s = do
-                xs <- MStream.toList s
-                return $ unstream $ Stream.unsafeFromList (MStream.size s) xs
+                xs <- MBundle.toList s
+                return $ unstream $ Bundle.unsafeFromList (MBundle.size s) xs
 
-unstreamPrimM :: (PrimMonad m, Vector v a) => MStream m a -> m (v a)
-{-# INLINE_STREAM unstreamPrimM #-}
+unstreamPrimM :: (PrimMonad m, Vector v a) => MBundle m u a -> m (v a)
+{-# INLINE_FUSED unstreamPrimM #-}
 unstreamPrimM s = M.munstream s >>= unsafeFreeze
 
 -- FIXME: the next two functions are only necessary for the specialisations
-unstreamPrimM_IO :: Vector v a => MStream IO a -> IO (v a)
+unstreamPrimM_IO :: Vector v a => MBundle IO u a -> IO (v a)
 {-# INLINE unstreamPrimM_IO #-}
 unstreamPrimM_IO = unstreamPrimM
 
-unstreamPrimM_ST :: Vector v a => MStream (ST s) a -> ST s (v a)
+unstreamPrimM_ST :: Vector v a => MBundle (ST s) u a -> ST s (v a)
 {-# INLINE unstreamPrimM_ST #-}
 unstreamPrimM_ST = unstreamPrimM
 
 {-# RULES
 
 "unstreamM[IO]" unstreamM = unstreamPrimM_IO
-"unstreamM[ST]" unstreamM = unstreamPrimM_ST
+"unstreamM[ST]" unstreamM = unstreamPrimM_ST  #-}
 
- #-}
 
 
+
 -- Recycling support
 -- -----------------
 
 -- | Construct a vector from a monadic initialiser.
 new :: Vector v a => New v a -> v a
-{-# INLINE_STREAM new #-}
+{-# INLINE_FUSED new #-}
 new m = m `seq` runST (unsafeFreeze =<< New.run m)
 
 -- | Convert a vector to an initialiser which, when run, produces a copy of
 -- the vector.
 clone :: Vector v a => v a -> New v a
-{-# INLINE_STREAM clone #-}
+{-# INLINE_FUSED clone #-}
 clone v = v `seq` New.create (
   do
     mv <- M.new (length v)
@@ -1998,13 +2050,12 @@
 -- | Generic definition of 'Prelude.showsPrec'
 showsPrec :: (Vector v a, Show a) => Int -> v a -> ShowS
 {-# INLINE showsPrec #-}
-showsPrec p v = showParen (p > 10) $ showString "fromList " . shows (toList v)
+showsPrec _ = shows . toList
 
 -- | Generic definition of 'Text.Read.readPrec'
 readPrec :: (Vector v a, Read a) => Read.ReadPrec (v a)
 {-# INLINE readPrec #-}
-readPrec = Read.parens $ Read.prec 10 $ do
-  Read.Ident "fromList" <- Read.lexP
+readPrec = do
   xs <- Read.readPrec
   return (fromList xs)
 
diff --git a/Data/Vector/Generic/Base.hs b/Data/Vector/Generic/Base.hs
--- a/Data/Vector/Generic/Base.hs
+++ b/Data/Vector/Generic/Base.hs
@@ -10,7 +10,7 @@
 -- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
 -- Stability   : experimental
 -- Portability : non-portable
--- 
+--
 -- Class of pure vectors
 --
 
@@ -18,8 +18,8 @@
   Vector(..), Mutable
 ) where
 
-import           Data.Vector.Generic.Mutable ( MVector )
-import qualified Data.Vector.Generic.Mutable as M
+import           Data.Vector.Generic.Mutable.Base ( MVector )
+import qualified Data.Vector.Generic.Mutable.Base as M
 
 import Control.Monad.Primitive
 
diff --git a/Data/Vector/Generic/Mutable.hs b/Data/Vector/Generic/Mutable.hs
--- a/Data/Vector/Generic/Mutable.hs
+++ b/Data/Vector/Generic/Mutable.hs
@@ -1,5 +1,4 @@
-{-# LANGUAGE MultiParamTypeClasses, BangPatterns, ScopedTypeVariables,
-             TypeFamilies #-}
+{-# LANGUAGE CPP, MultiParamTypeClasses, FlexibleContexts, BangPatterns, TypeFamilies, ScopedTypeVariables #-}
 -- |
 -- Module      : Data.Vector.Generic.Mutable
 -- Copyright   : (c) Roman Leshchinskiy 2008-2010
@@ -8,7 +7,7 @@
 -- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
 -- Stability   : experimental
 -- Portability : non-portable
--- 
+--
 -- Generic interface to mutable vectors
 --
 
@@ -35,13 +34,14 @@
 
   -- ** Growing
   grow, unsafeGrow,
+  growFront, unsafeGrowFront,
 
   -- ** Restricting memory usage
   clear,
 
   -- * Accessing individual elements
-  read, write, swap,
-  unsafeRead, unsafeWrite, unsafeSwap,
+  read, write, modify, swap, exchange,
+  unsafeRead, unsafeWrite, unsafeModify, unsafeSwap, unsafeExchange,
 
   -- * Modifying vectors
 
@@ -50,18 +50,23 @@
 
   -- * Internal operations
   mstream, mstreamR,
-  unstream, unstreamR,
+  unstream, unstreamR, vunstream,
   munstream, munstreamR,
   transform, transformR,
   fill, fillR,
   unsafeAccum, accum, unsafeUpdate, update, reverse,
-  unstablePartition, unstablePartitionStream, partitionStream
+  unstablePartition, unstablePartitionBundle, partitionBundle
 ) where
 
-import qualified Data.Vector.Fusion.Stream      as Stream
-import           Data.Vector.Fusion.Stream      ( Stream, MStream )
-import qualified Data.Vector.Fusion.Stream.Monadic as MStream
-import           Data.Vector.Fusion.Stream.Size
+import           Data.Vector.Generic.Mutable.Base
+import qualified Data.Vector.Generic.Base as V
+
+import qualified Data.Vector.Fusion.Bundle      as Bundle
+import           Data.Vector.Fusion.Bundle      ( Bundle, MBundle, Chunk(..) )
+import qualified Data.Vector.Fusion.Bundle.Monadic as MBundle
+import           Data.Vector.Fusion.Stream.Monadic ( Stream )
+import qualified Data.Vector.Fusion.Stream.Monadic as Stream
+import           Data.Vector.Fusion.Bundle.Size
 import           Data.Vector.Fusion.Util        ( delay_inline )
 
 import Control.Monad.Primitive ( PrimMonad, PrimState )
@@ -71,23 +76,12 @@
 
 #include "vector.h"
 
+{-
+type family Immutable (v :: * -> * -> *) :: * -> *
+
 -- | Class of mutable vectors parametrised with a primitive state token.
 --
--- Minimum complete implementation:
---
---   * 'basicLength'
---
---   * 'basicUnsafeSlice'
---
---   * 'basicOverlaps'
---
---   * 'basicUnsafeNew'
---
---   * 'basicUnsafeRead'
---
---   * 'basicUnsafeWrite'
---
-class MVector v a where
+class MBundle.Pointer u a => MVector v a where
   -- | Length of the mutable vector. This method should not be
   -- called directly, use 'length' instead.
   basicLength       :: v s a -> Int
@@ -129,6 +123,10 @@
   -- not be called directly, use 'set' instead.
   basicSet         :: PrimMonad m => v (PrimState m) a -> a -> m ()
 
+  basicUnsafeCopyPointer :: PrimMonad m => v (PrimState m) a
+                                        -> Immutable v a
+                                        -> m ()
+
   -- | Copy a vector. The two vectors may not overlap. This method should not
   -- be called directly, use 'unsafeCopy' instead.
   basicUnsafeCopy  :: PrimMonad m => v (PrimState m) a   -- ^ target
@@ -171,6 +169,14 @@
                | otherwise = basicUnsafeCopy (basicUnsafeSlice i (n-i) v)
                                              (basicUnsafeSlice 0 (n-i) v)
 
+  {-# INLINE basicUnsafeCopyPointer #-}
+  basicUnsafeCopyPointer !dst !src = do_copy 0 src
+    where
+      do_copy !i p | Just (x,q) <- MBundle.pget p = do
+                                                      basicUnsafeWrite dst i x
+                                                      do_copy (i+1) q
+                   | otherwise = return ()
+
   {-# INLINE basicUnsafeCopy #-}
   basicUnsafeCopy !dst !src = do_copy 0
     where
@@ -181,7 +187,7 @@
                             basicUnsafeWrite dst i x
                             do_copy (i+1)
                 | otherwise = return ()
-  
+
   {-# INLINE basicUnsafeMove #-}
   basicUnsafeMove !dst !src
     | basicOverlaps dst src = do
@@ -197,6 +203,7 @@
         return v'
     where
       n = basicLength v
+-}
 
 -- ------------------
 -- Internal functions
@@ -228,15 +235,15 @@
                   unsafeWrite v i' x
                   return (v, i')
   | otherwise = do
-                  (v', i) <- enlargeFront v
-                  let i' = i-1
+                  (v', j) <- enlargeFront v
+                  let i' = j-1
                   INTERNAL_CHECK(checkIndex) "unsafePrepend1" i' (length v')
                     $ unsafeWrite v' i' x
                   return (v', i')
 
-mstream :: (PrimMonad m, MVector v a) => v (PrimState m) a -> MStream m a
+mstream :: (PrimMonad m, MVector v a) => v (PrimState m) a -> Stream m a
 {-# INLINE mstream #-}
-mstream v = v `seq` n `seq` (MStream.unfoldrM get 0 `MStream.sized` Exact n)
+mstream v = v `seq` n `seq` (Stream.unfoldrM get 0)
   where
     n = length v
 
@@ -246,10 +253,10 @@
           | otherwise = return $ Nothing
 
 fill :: (PrimMonad m, MVector v a)
-           => v (PrimState m) a -> MStream m a -> m (v (PrimState m) a)
+     => v (PrimState m) a -> Stream m a -> m (v (PrimState m) a)
 {-# INLINE fill #-}
 fill v s = v `seq` do
-                     n' <- MStream.foldM put 0 s
+                     n' <- Stream.foldM put 0 s
                      return $ unsafeSlice 0 n' v
   where
     {-# INLINE_INNER put #-}
@@ -258,14 +265,15 @@
                   $ unsafeWrite v i x
                 return (i+1)
 
-transform :: (PrimMonad m, MVector v a)
-  => (MStream m a -> MStream m a) -> v (PrimState m) a -> m (v (PrimState m) a)
-{-# INLINE_STREAM transform #-}
+transform
+  :: (PrimMonad m, MVector v a)
+  => (Stream m a -> Stream m a) -> v (PrimState m) a -> m (v (PrimState m) a)
+{-# INLINE_FUSED transform #-}
 transform f v = fill v (f (mstream v))
 
-mstreamR :: (PrimMonad m, MVector v a) => v (PrimState m) a -> MStream m a
+mstreamR :: (PrimMonad m, MVector v a) => v (PrimState m) a -> Stream m a
 {-# INLINE mstreamR #-}
-mstreamR v = v `seq` n `seq` (MStream.unfoldrM get n `MStream.sized` Exact n)
+mstreamR v = v `seq` n `seq` (Stream.unfoldrM get n)
   where
     n = length v
 
@@ -277,10 +285,10 @@
         j = i-1
 
 fillR :: (PrimMonad m, MVector v a)
-           => v (PrimState m) a -> MStream m a -> m (v (PrimState m) a)
+      => v (PrimState m) a -> Stream m a -> m (v (PrimState m) a)
 {-# INLINE fillR #-}
 fillR v s = v `seq` do
-                      i <- MStream.foldM put n s
+                      i <- Stream.foldM put n s
                       return $ unsafeSlice i (n-i) v
   where
     n = length v
@@ -292,25 +300,28 @@
       where
         j = i-1
 
-transformR :: (PrimMonad m, MVector v a)
-  => (MStream m a -> MStream m a) -> v (PrimState m) a -> m (v (PrimState m) a)
-{-# INLINE_STREAM transformR #-}
+transformR
+  :: (PrimMonad m, MVector v a)
+  => (Stream m a -> Stream m a) -> v (PrimState m) a -> m (v (PrimState m) a)
+{-# INLINE_FUSED transformR #-}
 transformR f v = fillR v (f (mstreamR v))
 
--- | Create a new mutable vector and fill it with elements from the 'Stream'.
--- The vector will grow exponentially if the maximum size of the 'Stream' is
+-- | Create a new mutable vector and fill it with elements from the 'Bundle'.
+-- The vector will grow exponentially if the maximum size of the 'Bundle' is
 -- unknown.
-unstream :: (PrimMonad m, MVector v a) => Stream a -> m (v (PrimState m) a)
--- NOTE: replace INLINE_STREAM by INLINE? (also in unstreamR)
-{-# INLINE_STREAM unstream #-}
-unstream s = munstream (Stream.liftStream s)
+unstream :: (PrimMonad m, MVector v a)
+         => Bundle u a -> m (v (PrimState m) a)
+-- NOTE: replace INLINE_FUSED by INLINE? (also in unstreamR)
+{-# INLINE_FUSED unstream #-}
+unstream s = munstream (Bundle.lift s)
 
 -- | Create a new mutable vector and fill it with elements from the monadic
 -- stream. The vector will grow exponentially if the maximum size of the stream
 -- is unknown.
-munstream :: (PrimMonad m, MVector v a) => MStream m a -> m (v (PrimState m) a)
-{-# INLINE_STREAM munstream #-}
-munstream s = case upperBound (MStream.size s) of
+munstream :: (PrimMonad m, MVector v a)
+          => MBundle m u a -> m (v (PrimState m) a)
+{-# INLINE_FUSED munstream #-}
+munstream s = case upperBound (MBundle.size s) of
                Just n  -> munstreamMax     s n
                Nothing -> munstreamUnknown s
 
@@ -320,12 +331,12 @@
 -- the shape of the vector) and one for when the vector has grown. To see the
 -- problem simply compile this:
 --
--- fromList = Data.Vector.Unboxed.unstream . Stream.fromList
+-- fromList = Data.Vector.Unboxed.unstream . Bundle.fromList
 --
 -- I'm not sure this still applies (19/04/2010)
 
-munstreamMax
-  :: (PrimMonad m, MVector v a) => MStream m a -> Int -> m (v (PrimState m) a)
+munstreamMax :: (PrimMonad m, MVector v a)
+             => MBundle m u a -> Int -> m (v (PrimState m) a)
 {-# INLINE munstreamMax #-}
 munstreamMax s n
   = do
@@ -335,17 +346,17 @@
                        INTERNAL_CHECK(checkIndex) "munstreamMax" i n
                          $ unsafeWrite v i x
                        return (i+1)
-      n' <- MStream.foldM' put 0 s
+      n' <- MBundle.foldM' put 0 s
       return $ INTERNAL_CHECK(checkSlice) "munstreamMax" 0 n' n
              $ unsafeSlice 0 n' v
 
-munstreamUnknown
-  :: (PrimMonad m, MVector v a) => MStream m a -> m (v (PrimState m) a)
+munstreamUnknown :: (PrimMonad m, MVector v a)
+                 => MBundle m u a -> m (v (PrimState m) a)
 {-# INLINE munstreamUnknown #-}
 munstreamUnknown s
   = do
       v <- unsafeNew 0
-      (v', n) <- MStream.foldM put (v, 0) s
+      (v', n) <- MBundle.foldM put (v, 0) s
       return $ INTERNAL_CHECK(checkSlice) "munstreamUnknown" 0 n (length v')
              $ unsafeSlice 0 n v'
   where
@@ -354,25 +365,103 @@
                     v' <- unsafeAppend1 v i x
                     return (v',i+1)
 
--- | Create a new mutable vector and fill it with elements from the 'Stream'
+
+
+
+
+
+
+-- | Create a new mutable vector and fill it with elements from the 'Bundle'.
+-- The vector will grow exponentially if the maximum size of the 'Bundle' is
+-- unknown.
+vunstream :: (PrimMonad m, V.Vector v a)
+         => Bundle v a -> m (V.Mutable v (PrimState m) a)
+-- NOTE: replace INLINE_FUSED by INLINE? (also in unstreamR)
+{-# INLINE_FUSED vunstream #-}
+vunstream s = vmunstream (Bundle.lift s)
+
+-- | Create a new mutable vector and fill it with elements from the monadic
+-- stream. The vector will grow exponentially if the maximum size of the stream
+-- is unknown.
+vmunstream :: (PrimMonad m, V.Vector v a)
+           => MBundle m v a -> m (V.Mutable v (PrimState m) a)
+{-# INLINE_FUSED vmunstream #-}
+vmunstream s = case upperBound (MBundle.size s) of
+               Just n  -> vmunstreamMax     s n
+               Nothing -> vmunstreamUnknown s
+
+-- FIXME: I can't think of how to prevent GHC from floating out
+-- unstreamUnknown. That is bad because SpecConstr then generates two
+-- specialisations: one for when it is called from unstream (it doesn't know
+-- the shape of the vector) and one for when the vector has grown. To see the
+-- problem simply compile this:
+--
+-- fromList = Data.Vector.Unboxed.unstream . Bundle.fromList
+--
+-- I'm not sure this still applies (19/04/2010)
+
+vmunstreamMax :: (PrimMonad m, V.Vector v a)
+              => MBundle m v a -> Int -> m (V.Mutable v (PrimState m) a)
+{-# INLINE vmunstreamMax #-}
+vmunstreamMax s n
+  = do
+      v <- INTERNAL_CHECK(checkLength) "munstreamMax" n
+           $ unsafeNew n
+      let {-# INLINE_INNER copyChunk #-}
+          copyChunk i (Chunk m f) =
+            INTERNAL_CHECK(checkSlice) "munstreamMax.copyChunk" i m (length v) $ do
+              f (basicUnsafeSlice i m v)
+              return (i+m)
+
+      n' <- Stream.foldlM' copyChunk 0 (MBundle.chunks s)
+      return $ INTERNAL_CHECK(checkSlice) "munstreamMax" 0 n' n
+             $ unsafeSlice 0 n' v
+
+vmunstreamUnknown :: (PrimMonad m, V.Vector v a)
+                 => MBundle m v a -> m (V.Mutable v (PrimState m) a)
+{-# INLINE vmunstreamUnknown #-}
+vmunstreamUnknown s
+  = do
+      v <- unsafeNew 0
+      (v', n) <- Stream.foldlM copyChunk (v,0) (MBundle.chunks s)
+      return $ INTERNAL_CHECK(checkSlice) "munstreamUnknown" 0 n (length v')
+             $ unsafeSlice 0 n v'
+  where
+    {-# INLINE_INNER copyChunk #-}
+    copyChunk (v,i) (Chunk n f)
+      = do
+          let j = i+n
+          v' <- if basicLength v < j
+                  then unsafeGrow v (delay_inline max (enlarge_delta v) (j - basicLength v))
+                  else return v
+          INTERNAL_CHECK(checkSlice) "munstreamUnknown.copyChunk" i n (length v')
+            $ f (basicUnsafeSlice i n v')
+          return (v',j)
+
+
+
+
+-- | Create a new mutable vector and fill it with elements from the 'Bundle'
 -- from right to left. The vector will grow exponentially if the maximum size
--- of the 'Stream' is unknown.
-unstreamR :: (PrimMonad m, MVector v a) => Stream a -> m (v (PrimState m) a)
--- NOTE: replace INLINE_STREAM by INLINE? (also in unstream)
-{-# INLINE_STREAM unstreamR #-}
-unstreamR s = munstreamR (Stream.liftStream s)
+-- of the 'Bundle' is unknown.
+unstreamR :: (PrimMonad m, MVector v a)
+          => Bundle u a -> m (v (PrimState m) a)
+-- NOTE: replace INLINE_FUSED by INLINE? (also in unstream)
+{-# INLINE_FUSED unstreamR #-}
+unstreamR s = munstreamR (Bundle.lift s)
 
 -- | Create a new mutable vector and fill it with elements from the monadic
 -- stream from right to left. The vector will grow exponentially if the maximum
 -- size of the stream is unknown.
-munstreamR :: (PrimMonad m, MVector v a) => MStream m a -> m (v (PrimState m) a)
-{-# INLINE_STREAM munstreamR #-}
-munstreamR s = case upperBound (MStream.size s) of
+munstreamR :: (PrimMonad m, MVector v a)
+           => MBundle m u a -> m (v (PrimState m) a)
+{-# INLINE_FUSED munstreamR #-}
+munstreamR s = case upperBound (MBundle.size s) of
                Just n  -> munstreamRMax     s n
                Nothing -> munstreamRUnknown s
 
-munstreamRMax
-  :: (PrimMonad m, MVector v a) => MStream m a -> Int -> m (v (PrimState m) a)
+munstreamRMax :: (PrimMonad m, MVector v a)
+              => MBundle m u a -> Int -> m (v (PrimState m) a)
 {-# INLINE munstreamRMax #-}
 munstreamRMax s n
   = do
@@ -383,17 +472,17 @@
                       INTERNAL_CHECK(checkIndex) "munstreamRMax" i' n
                         $ unsafeWrite v i' x
                       return i'
-      i <- MStream.foldM' put n s
+      i <- MBundle.foldM' put n s
       return $ INTERNAL_CHECK(checkSlice) "munstreamRMax" i (n-i) n
              $ unsafeSlice i (n-i) v
 
-munstreamRUnknown
-  :: (PrimMonad m, MVector v a) => MStream m a -> m (v (PrimState m) a)
+munstreamRUnknown :: (PrimMonad m, MVector v a)
+                  => MBundle m u a -> m (v (PrimState m) a)
 {-# INLINE munstreamRUnknown #-}
 munstreamRUnknown s
   = do
       v <- unsafeNew 0
-      (v', i) <- MStream.foldM put (v, 0) s
+      (v', i) <- MBundle.foldM put (v, 0) s
       let n = length v'
       return $ INTERNAL_CHECK(checkSlice) "unstreamRUnknown" i (n-i) n
              $ unsafeSlice i (n-i) v'
@@ -481,7 +570,7 @@
 -- Overlapping
 -- -----------
 
--- Check whether two vectors overlap.
+-- | Check whether two vectors overlap.
 overlaps :: MVector v a => v s a -> v s a -> Bool
 {-# INLINE overlaps #-}
 overlaps = basicOverlaps
@@ -493,7 +582,7 @@
 new :: (PrimMonad m, MVector v a) => Int -> m (v (PrimState m) a)
 {-# INLINE new #-}
 new n = BOUNDS_CHECK(checkLength) "new" n
-      $ unsafeNew n
+      $ unsafeNew n >>= \v -> basicInitialize v >> return v
 
 -- | Create a mutable vector of the given length. The length is not checked.
 unsafeNew :: (PrimMonad m, MVector v a) => Int -> m (v (PrimState m) a)
@@ -511,7 +600,7 @@
 -- and fill it with values produced by repeatedly executing the monadic action.
 replicateM :: (PrimMonad m, MVector v a) => Int -> m a -> m (v (PrimState m) a)
 {-# INLINE replicateM #-}
-replicateM n m = munstream (MStream.replicateM n m)
+replicateM n m = munstream (MBundle.replicateM n m)
 
 -- | Create a copy of a mutable vector.
 clone :: (PrimMonad m, MVector v a) => v (PrimState m) a -> m (v (PrimState m) a)
@@ -530,27 +619,37 @@
                 => v (PrimState m) a -> Int -> m (v (PrimState m) a)
 {-# INLINE grow #-}
 grow v by = BOUNDS_CHECK(checkLength) "grow" by
-          $ unsafeGrow v by
+          $ do vnew <- unsafeGrow v by
+               basicInitialize $ basicUnsafeSlice (length v) by vnew
+               return vnew
 
 growFront :: (PrimMonad m, MVector v a)
                 => v (PrimState m) a -> Int -> m (v (PrimState m) a)
 {-# INLINE growFront #-}
 growFront v by = BOUNDS_CHECK(checkLength) "growFront" by
-               $ unsafeGrowFront v by
+               $ do vnew <- unsafeGrowFront v by
+                    basicInitialize $ basicUnsafeSlice 0 by vnew
+                    return vnew
 
+enlarge_delta :: MVector v a => v s a -> Int
 enlarge_delta v = max (length v) 1
 
 -- | Grow a vector logarithmically
 enlarge :: (PrimMonad m, MVector v a)
                 => v (PrimState m) a -> m (v (PrimState m) a)
 {-# INLINE enlarge #-}
-enlarge v = unsafeGrow v (enlarge_delta v)
+enlarge v = do vnew <- unsafeGrow v by
+               basicInitialize $ basicUnsafeSlice (length v) by vnew
+               return vnew
+  where
+    by = enlarge_delta v
 
 enlargeFront :: (PrimMonad m, MVector v a)
                 => v (PrimState m) a -> m (v (PrimState m) a, Int)
 {-# INLINE enlargeFront #-}
 enlargeFront v = do
                    v' <- unsafeGrowFront v by
+                   basicInitialize $ basicUnsafeSlice 0 by v'
                    return (v', by)
   where
     by = enlarge_delta v
@@ -577,7 +676,7 @@
 -- ------------------------
 
 -- | Reset all elements of the vector to some undefined value, clearing all
--- references to external objects. This is usually a noop for unboxed vectors. 
+-- references to external objects. This is usually a noop for unboxed vectors.
 clear :: (PrimMonad m, MVector v a) => v (PrimState m) a -> m ()
 {-# INLINE clear #-}
 clear = basicClear
@@ -597,6 +696,12 @@
 write v i x = BOUNDS_CHECK(checkIndex) "write" i (length v)
             $ unsafeWrite v i x
 
+-- | Modify the element at the given position.
+modify :: (PrimMonad m, MVector v a) => v (PrimState m) a -> (a -> a) -> Int -> m ()
+{-# INLINE modify #-}
+modify v f i = BOUNDS_CHECK(checkIndex) "modify" i (length v)
+             $ unsafeModify v f i
+
 -- | Swap the elements at the given positions.
 swap :: (PrimMonad m, MVector v a) => v (PrimState m) a -> Int -> Int -> m ()
 {-# INLINE swap #-}
@@ -623,6 +728,13 @@
 unsafeWrite v i x = UNSAFE_CHECK(checkIndex) "unsafeWrite" i (length v)
                   $ basicUnsafeWrite v i x
 
+-- | Modify the element at the given position. No bounds checks are performed.
+unsafeModify :: (PrimMonad m, MVector v a) => v (PrimState m) a -> (a -> a) -> Int -> m ()
+{-# INLINE unsafeModify #-}
+unsafeModify v f i = UNSAFE_CHECK(checkIndex) "unsafeModify" i (length v)
+                   $ basicUnsafeRead v i >>= \x ->
+                     basicUnsafeWrite v i (f x)
+
 -- | Swap the elements at the given positions. No bounds checks are performed.
 unsafeSwap :: (PrimMonad m, MVector v a)
                 => v (PrimState m) a -> Int -> Int -> m ()
@@ -667,7 +779,7 @@
 
 -- | Move the contents of a vector. The two vectors must have the same
 -- length.
--- 
+--
 -- If the vectors do not overlap, then this is equivalent to 'copy'.
 -- Otherwise, the copying is performed as if the source vector were
 -- copied to a temporary vector and then the temporary vector was copied
@@ -693,7 +805,7 @@
 
 -- | Move the contents of a vector. The two vectors must have the same
 -- length, but this is not checked.
--- 
+--
 -- If the vectors do not overlap, then this is equivalent to 'unsafeCopy'.
 -- Otherwise, the copying is performed as if the source vector were
 -- copied to a temporary vector and then the temporary vector was copied
@@ -710,9 +822,9 @@
 -- ------------
 
 accum :: (PrimMonad m, MVector v a)
-        => (a -> b -> a) -> v (PrimState m) a -> Stream (Int, b) -> m ()
+      => (a -> b -> a) -> v (PrimState m) a -> Bundle u (Int, b) -> m ()
 {-# INLINE accum #-}
-accum f !v s = Stream.mapM_ upd s
+accum f !v s = Bundle.mapM_ upd s
   where
     {-# INLINE_INNER upd #-}
     upd (i,b) = do
@@ -723,9 +835,9 @@
     !n = length v
 
 update :: (PrimMonad m, MVector v a)
-                        => v (PrimState m) a -> Stream (Int, a) -> m ()
+                        => v (PrimState m) a -> Bundle u (Int, a) -> m ()
 {-# INLINE update #-}
-update !v s = Stream.mapM_ upd s
+update !v s = Bundle.mapM_ upd s
   where
     {-# INLINE_INNER upd #-}
     upd (i,b) = BOUNDS_CHECK(checkIndex) "update" i n
@@ -734,9 +846,9 @@
     !n = length v
 
 unsafeAccum :: (PrimMonad m, MVector v a)
-            => (a -> b -> a) -> v (PrimState m) a -> Stream (Int, b) -> m ()
+            => (a -> b -> a) -> v (PrimState m) a -> Bundle u (Int, b) -> m ()
 {-# INLINE unsafeAccum #-}
-unsafeAccum f !v s = Stream.mapM_ upd s
+unsafeAccum f !v s = Bundle.mapM_ upd s
   where
     {-# INLINE_INNER upd #-}
     upd (i,b) = do
@@ -747,9 +859,9 @@
     !n = length v
 
 unsafeUpdate :: (PrimMonad m, MVector v a)
-                        => v (PrimState m) a -> Stream (Int, a) -> m ()
+                        => v (PrimState m) a -> Bundle u (Int, a) -> m ()
 {-# INLINE unsafeUpdate #-}
-unsafeUpdate !v s = Stream.mapM_ upd s
+unsafeUpdate !v s = Bundle.mapM_ upd s
   where
     {-# INLINE_INNER upd #-}
     upd (i,b) = UNSAFE_CHECK(checkIndex) "accum" i n
@@ -795,16 +907,16 @@
                                from_left (i+1) j
                         else from_right i (j-1)
 
-unstablePartitionStream :: (PrimMonad m, MVector v a)
-        => (a -> Bool) -> Stream a -> m (v (PrimState m) a, v (PrimState m) a)
-{-# INLINE unstablePartitionStream #-}
-unstablePartitionStream f s
-  = case upperBound (Stream.size s) of
+unstablePartitionBundle :: (PrimMonad m, MVector v a)
+        => (a -> Bool) -> Bundle u a -> m (v (PrimState m) a, v (PrimState m) a)
+{-# INLINE unstablePartitionBundle #-}
+unstablePartitionBundle f s
+  = case upperBound (Bundle.size s) of
       Just n  -> unstablePartitionMax f s n
       Nothing -> partitionUnknown f s
 
 unstablePartitionMax :: (PrimMonad m, MVector v a)
-        => (a -> Bool) -> Stream a -> Int
+        => (a -> Bool) -> Bundle u a -> Int
         -> m (v (PrimState m) a, v (PrimState m) a)
 {-# INLINE unstablePartitionMax #-}
 unstablePartitionMax f s n
@@ -819,20 +931,20 @@
             | otherwise = do
                             unsafeWrite v (j-1) x
                             return (i, j-1)
-                                
-      (i,j) <- Stream.foldM' put (0, n) s
+
+      (i,j) <- Bundle.foldM' put (0, n) s
       return (unsafeSlice 0 i v, unsafeSlice j (n-j) v)
 
-partitionStream :: (PrimMonad m, MVector v a)
-        => (a -> Bool) -> Stream a -> m (v (PrimState m) a, v (PrimState m) a)
-{-# INLINE partitionStream #-}
-partitionStream f s
-  = case upperBound (Stream.size s) of
+partitionBundle :: (PrimMonad m, MVector v a)
+        => (a -> Bool) -> Bundle u a -> m (v (PrimState m) a, v (PrimState m) a)
+{-# INLINE partitionBundle #-}
+partitionBundle f s
+  = case upperBound (Bundle.size s) of
       Just n  -> partitionMax f s n
       Nothing -> partitionUnknown f s
 
 partitionMax :: (PrimMonad m, MVector v a)
-  => (a -> Bool) -> Stream a -> Int -> m (v (PrimState m) a, v (PrimState m) a)
+  => (a -> Bool) -> Bundle u a -> Int -> m (v (PrimState m) a, v (PrimState m) a)
 {-# INLINE partitionMax #-}
 partitionMax f s n
   = do
@@ -848,9 +960,9 @@
             | otherwise = let j' = j-1 in
                           do
                             unsafeWrite v j' x
-                            return (i,j') 
-                            
-      (i,j) <- Stream.foldM' put (0,n) s
+                            return (i,j')
+
+      (i,j) <- Bundle.foldM' put (0,n) s
       INTERNAL_CHECK(check) "partitionMax" "invalid indices" (i <= j)
         $ return ()
       let l = unsafeSlice 0 i v
@@ -859,13 +971,13 @@
       return (l,r)
 
 partitionUnknown :: (PrimMonad m, MVector v a)
-        => (a -> Bool) -> Stream a -> m (v (PrimState m) a, v (PrimState m) a)
+        => (a -> Bool) -> Bundle u a -> m (v (PrimState m) a, v (PrimState m) a)
 {-# INLINE partitionUnknown #-}
 partitionUnknown f s
   = do
       v1 <- unsafeNew 0
       v2 <- unsafeNew 0
-      (v1', n1, v2', n2) <- Stream.foldM' put (v1, 0, v2, 0) s
+      (v1', n1, v2', n2) <- Bundle.foldM' put (v1, 0, v2, 0) s
       INTERNAL_CHECK(checkSlice) "partitionUnknown" 0 n1 (length v1')
         $ INTERNAL_CHECK(checkSlice) "partitionUnknown" 0 n2 (length v2')
         $ return (unsafeSlice 0 n1 v1', unsafeSlice 0 n2 v2')
diff --git a/Data/Vector/Generic/Mutable/Base.hs b/Data/Vector/Generic/Mutable/Base.hs
new file mode 100644
--- /dev/null
+++ b/Data/Vector/Generic/Mutable/Base.hs
@@ -0,0 +1,145 @@
+{-# LANGUAGE CPP, MultiParamTypeClasses, BangPatterns, TypeFamilies #-}
+-- |
+-- Module      : Data.Vector.Generic.Mutable.Base
+-- Copyright   : (c) Roman Leshchinskiy 2008-2011
+-- License     : BSD-style
+--
+-- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
+-- Stability   : experimental
+-- Portability : non-portable
+--
+-- Class of mutable vectors
+--
+
+module Data.Vector.Generic.Mutable.Base (
+  MVector(..)
+) where
+
+import Control.Monad.Primitive ( PrimMonad, PrimState )
+
+-- Data.Vector.Internal.Check is unused
+#define NOT_VECTOR_MODULE
+#include "vector.h"
+
+-- | Class of mutable vectors parametrised with a primitive state token.
+--
+class MVector v a where
+  -- | Length of the mutable vector. This method should not be
+  -- called directly, use 'length' instead.
+  basicLength       :: v s a -> Int
+
+  -- | Yield a part of the mutable vector without copying it. This method
+  -- should not be called directly, use 'unsafeSlice' instead.
+  basicUnsafeSlice :: Int  -- ^ starting index
+                   -> Int  -- ^ length of the slice
+                   -> v s a
+                   -> v s a
+
+  -- | Check whether two vectors overlap. This method should not be
+  -- called directly, use 'overlaps' instead.
+  basicOverlaps    :: v s a -> v s a -> Bool
+
+  -- | Create a mutable vector of the given length. This method should not be
+  -- called directly, use 'unsafeNew' instead.
+  basicUnsafeNew   :: PrimMonad m => Int -> m (v (PrimState m) a)
+
+  -- | Initialize a vector to a standard value. This is intended to be called as
+  -- part of the safe new operation (and similar operations), to properly blank
+  -- the newly allocated memory if necessary.
+  --
+  -- Vectors that are necessarily initialized as part of creation may implement
+  -- this as a no-op.
+  basicInitialize :: PrimMonad m => v (PrimState m) a -> m ()
+
+  -- | Create a mutable vector of the given length and fill it with an
+  -- initial value. This method should not be called directly, use
+  -- 'replicate' instead.
+  basicUnsafeReplicate :: PrimMonad m => Int -> a -> m (v (PrimState m) a)
+
+  -- | Yield the element at the given position. This method should not be
+  -- called directly, use 'unsafeRead' instead.
+  basicUnsafeRead  :: PrimMonad m => v (PrimState m) a -> Int -> m a
+
+  -- | Replace the element at the given position. This method should not be
+  -- called directly, use 'unsafeWrite' instead.
+  basicUnsafeWrite :: PrimMonad m => v (PrimState m) a -> Int -> a -> m ()
+
+  -- | Reset all elements of the vector to some undefined value, clearing all
+  -- references to external objects. This is usually a noop for unboxed
+  -- vectors. This method should not be called directly, use 'clear' instead.
+  basicClear       :: PrimMonad m => v (PrimState m) a -> m ()
+
+  -- | Set all elements of the vector to the given value. This method should
+  -- not be called directly, use 'set' instead.
+  basicSet         :: PrimMonad m => v (PrimState m) a -> a -> m ()
+
+  -- | Copy a vector. The two vectors may not overlap. This method should not
+  -- be called directly, use 'unsafeCopy' instead.
+  basicUnsafeCopy  :: PrimMonad m => v (PrimState m) a   -- ^ target
+                                  -> v (PrimState m) a   -- ^ source
+                                  -> m ()
+
+  -- | Move the contents of a vector. The two vectors may overlap. This method
+  -- should not be called directly, use 'unsafeMove' instead.
+  basicUnsafeMove  :: PrimMonad m => v (PrimState m) a   -- ^ target
+                                  -> v (PrimState m) a   -- ^ source
+                                  -> m ()
+
+  -- | Grow a vector by the given number of elements. This method should not be
+  -- called directly, use 'unsafeGrow' instead.
+  basicUnsafeGrow  :: PrimMonad m => v (PrimState m) a -> Int
+                                                       -> m (v (PrimState m) a)
+
+  {-# INLINE basicUnsafeReplicate #-}
+  basicUnsafeReplicate n x
+    = do
+        v <- basicUnsafeNew n
+        basicSet v x
+        return v
+
+  {-# INLINE basicClear #-}
+  basicClear _ = return ()
+
+  {-# INLINE basicSet #-}
+  basicSet !v x
+    | n == 0    = return ()
+    | otherwise = do
+                    basicUnsafeWrite v 0 x
+                    do_set 1
+    where
+      !n = basicLength v
+
+      do_set i | 2*i < n = do basicUnsafeCopy (basicUnsafeSlice i i v)
+                                              (basicUnsafeSlice 0 i v)
+                              do_set (2*i)
+               | otherwise = basicUnsafeCopy (basicUnsafeSlice i (n-i) v)
+                                             (basicUnsafeSlice 0 (n-i) v)
+
+  {-# INLINE basicUnsafeCopy #-}
+  basicUnsafeCopy !dst !src = do_copy 0
+    where
+      !n = basicLength src
+
+      do_copy i | i < n = do
+                            x <- basicUnsafeRead src i
+                            basicUnsafeWrite dst i x
+                            do_copy (i+1)
+                | otherwise = return ()
+
+  {-# INLINE basicUnsafeMove #-}
+  basicUnsafeMove !dst !src
+    | basicOverlaps dst src = do
+        srcCopy <- basicUnsafeNew (basicLength src)
+        basicUnsafeCopy srcCopy src
+        basicUnsafeCopy dst srcCopy
+    | otherwise = basicUnsafeCopy dst src
+
+  {-# INLINE basicUnsafeGrow #-}
+  basicUnsafeGrow v by
+    = do
+        v' <- basicUnsafeNew (n+by)
+        basicUnsafeCopy (basicUnsafeSlice 0 n v') v
+        return v'
+    where
+      n = basicLength v
+
diff --git a/Data/Vector/Generic/New.hs b/Data/Vector/Generic/New.hs
--- a/Data/Vector/Generic/New.hs
+++ b/Data/Vector/Generic/New.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE Rank2Types, FlexibleContexts #-}
+{-# LANGUAGE CPP, Rank2Types, FlexibleContexts, MultiParamTypeClasses #-}
 
 -- |
 -- Module      : Data.Vector.Generic.New
@@ -8,30 +8,33 @@
 -- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
 -- Stability   : experimental
 -- Portability : non-portable
--- 
+--
 -- Purely functional interface to initialisation of mutable vectors
 --
 
 module Data.Vector.Generic.New (
-  New(..), create, run, runPrim, apply, modify, modifyWithStream,
+  New(..), create, run, runPrim, apply, modify, modifyWithBundle,
   unstream, transform, unstreamR, transformR,
   slice, init, tail, take, drop,
   unsafeSlice, unsafeInit, unsafeTail
 ) where
 
 import qualified Data.Vector.Generic.Mutable as MVector
-import           Data.Vector.Generic.Mutable ( MVector )
 
 import           Data.Vector.Generic.Base ( Vector, Mutable )
 
-import           Data.Vector.Fusion.Stream ( Stream, MStream )
-import qualified Data.Vector.Fusion.Stream as Stream
+import           Data.Vector.Fusion.Bundle ( Bundle )
+import qualified Data.Vector.Fusion.Bundle as Bundle
+import           Data.Vector.Fusion.Stream.Monadic ( Stream )
+import           Data.Vector.Fusion.Bundle.Size
 
 import Control.Monad.Primitive
 import Control.Monad.ST ( ST )
 import Control.Monad  ( liftM )
 import Prelude hiding ( init, tail, take, drop, reverse, map, filter )
 
+-- Data.Vector.Internal.Check is unused
+#define NOT_VECTOR_MODULE
 #include "vector.h"
 
 data New v a = New (forall s. ST s (Mutable v s a))
@@ -56,117 +59,120 @@
 {-# INLINE modify #-}
 modify f (New p) = New (do { v <- p; f v; return v })
 
-modifyWithStream :: (forall s. Mutable v s a -> Stream b -> ST s ())
-                 -> New v a -> Stream b -> New v a
-{-# INLINE_STREAM modifyWithStream #-}
-modifyWithStream f (New p) s = s `seq` New (do { v <- p; f v s; return v })
+modifyWithBundle :: (forall s. Mutable v s a -> Bundle u b -> ST s ())
+                 -> New v a -> Bundle u b -> New v a
+{-# INLINE_FUSED modifyWithBundle #-}
+modifyWithBundle f (New p) s = s `seq` New (do { v <- p; f v s; return v })
 
-unstream :: Vector v a => Stream a -> New v a
-{-# INLINE_STREAM unstream #-}
-unstream s = s `seq` New (MVector.unstream s)
+unstream :: Vector v a => Bundle v a -> New v a
+{-# INLINE_FUSED unstream #-}
+unstream s = s `seq` New (MVector.vunstream s)
 
-transform :: Vector v a =>
-        (forall m. Monad m => MStream m a -> MStream m a) -> New v a -> New v a
-{-# INLINE_STREAM transform #-}
-transform f (New p) = New (MVector.transform f =<< p)
+transform
+  :: Vector v a => (forall m. Monad m => Stream m a -> Stream m a)
+                -> (Size -> Size) -> New v a -> New v a
+{-# INLINE_FUSED transform #-}
+transform f _ (New p) = New (MVector.transform f =<< p)
 
 {-# RULES
 
 "transform/transform [New]"
-  forall (f :: forall m. Monad m => MStream m a -> MStream m a)
-         (g :: forall m. Monad m => MStream m a -> MStream m a)
-         p .
-  transform f (transform g p) = transform (f . g) p
+  forall (f1 :: forall m. Monad m => Stream m a -> Stream m a)
+         (f2 :: forall m. Monad m => Stream m a -> Stream m a)
+         g1 g2 p .
+  transform f1 g1 (transform f2 g2 p) = transform (f1 . f2) (g1 . g2) p
 
 "transform/unstream [New]"
-  forall (f :: forall m. Monad m => MStream m a -> MStream m a)
-         s.
-  transform f (unstream s) = unstream (f s)
+  forall (f :: forall m. Monad m => Stream m a -> Stream m a)
+         g s.
+  transform f g (unstream s) = unstream (Bundle.inplace f g s)  #-}
 
- #-}
 
 
-unstreamR :: Vector v a => Stream a -> New v a
-{-# INLINE_STREAM unstreamR #-}
+
+unstreamR :: Vector v a => Bundle v a -> New v a
+{-# INLINE_FUSED unstreamR #-}
 unstreamR s = s `seq` New (MVector.unstreamR s)
 
-transformR :: Vector v a =>
-        (forall m. Monad m => MStream m a -> MStream m a) -> New v a -> New v a
-{-# INLINE_STREAM transformR #-}
-transformR f (New p) = New (MVector.transformR f =<< p)
+transformR
+  :: Vector v a => (forall m. Monad m => Stream m a -> Stream m a)
+                -> (Size -> Size) -> New v a -> New v a
+{-# INLINE_FUSED transformR #-}
+transformR f _ (New p) = New (MVector.transformR f =<< p)
 
 {-# RULES
 
 "transformR/transformR [New]"
-  forall (f :: forall m. Monad m => MStream m a -> MStream m a)
-         (g :: forall m. Monad m => MStream m a -> MStream m a)
+  forall (f1 :: forall m. Monad m => Stream m a -> Stream m a)
+         (f2 :: forall m. Monad m => Stream m a -> Stream m a)
+         g1 g2
          p .
-  transformR f (transformR g p) = transformR (f . g) p
+  transformR f1 g1 (transformR f2 g2 p) = transformR (f1 . f2) (g1 . g2) p
 
 "transformR/unstreamR [New]"
-  forall (f :: forall m. Monad m => MStream m a -> MStream m a)
-         s.
-  transformR f (unstreamR s) = unstreamR (f s)
+  forall (f :: forall m. Monad m => Stream m a -> Stream m a)
+         g s.
+  transformR f g (unstreamR s) = unstreamR (Bundle.inplace f g s)  #-}
 
- #-}
 
+
 slice :: Vector v a => Int -> Int -> New v a -> New v a
-{-# INLINE_STREAM slice #-}
+{-# INLINE_FUSED slice #-}
 slice i n m = apply (MVector.slice i n) m
 
 init :: Vector v a => New v a -> New v a
-{-# INLINE_STREAM init #-}
+{-# INLINE_FUSED init #-}
 init m = apply MVector.init m
 
 tail :: Vector v a => New v a -> New v a
-{-# INLINE_STREAM tail #-}
+{-# INLINE_FUSED tail #-}
 tail m = apply MVector.tail m
 
 take :: Vector v a => Int -> New v a -> New v a
-{-# INLINE_STREAM take #-}
+{-# INLINE_FUSED take #-}
 take n m = apply (MVector.take n) m
 
 drop :: Vector v a => Int -> New v a -> New v a
-{-# INLINE_STREAM drop #-}
+{-# INLINE_FUSED drop #-}
 drop n m = apply (MVector.drop n) m
 
 unsafeSlice :: Vector v a => Int -> Int -> New v a -> New v a
-{-# INLINE_STREAM unsafeSlice #-}
+{-# INLINE_FUSED unsafeSlice #-}
 unsafeSlice i n m = apply (MVector.unsafeSlice i n) m
 
 unsafeInit :: Vector v a => New v a -> New v a
-{-# INLINE_STREAM unsafeInit #-}
+{-# INLINE_FUSED unsafeInit #-}
 unsafeInit m = apply MVector.unsafeInit m
 
 unsafeTail :: Vector v a => New v a -> New v a
-{-# INLINE_STREAM unsafeTail #-}
+{-# INLINE_FUSED unsafeTail #-}
 unsafeTail m = apply MVector.unsafeTail m
 
 {-# RULES
 
 "slice/unstream [New]" forall i n s.
-  slice i n (unstream s) = unstream (Stream.slice i n s)
+  slice i n (unstream s) = unstream (Bundle.slice i n s)
 
 "init/unstream [New]" forall s.
-  init (unstream s) = unstream (Stream.init s)
+  init (unstream s) = unstream (Bundle.init s)
 
 "tail/unstream [New]" forall s.
-  tail (unstream s) = unstream (Stream.tail s)
+  tail (unstream s) = unstream (Bundle.tail s)
 
 "take/unstream [New]" forall n s.
-  take n (unstream s) = unstream (Stream.take n s)
+  take n (unstream s) = unstream (Bundle.take n s)
 
 "drop/unstream [New]" forall n s.
-  drop n (unstream s) = unstream (Stream.drop n s)
+  drop n (unstream s) = unstream (Bundle.drop n s)
 
 "unsafeSlice/unstream [New]" forall i n s.
-  unsafeSlice i n (unstream s) = unstream (Stream.slice i n s)
+  unsafeSlice i n (unstream s) = unstream (Bundle.slice i n s)
 
 "unsafeInit/unstream [New]" forall s.
-  unsafeInit (unstream s) = unstream (Stream.init s)
+  unsafeInit (unstream s) = unstream (Bundle.init s)
 
 "unsafeTail/unstream [New]" forall s.
-  unsafeTail (unstream s) = unstream (Stream.tail s)
+  unsafeTail (unstream s) = unstream (Bundle.tail s)   #-}
 
-  #-}
+
 
diff --git a/Data/Vector/Internal/Check.hs b/Data/Vector/Internal/Check.hs
--- a/Data/Vector/Internal/Check.hs
+++ b/Data/Vector/Internal/Check.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE CPP #-}
+
 -- |
 -- Module      : Data.Vector.Internal.Check
 -- Copyright   : (c) Roman Leshchinskiy 2009
@@ -37,12 +39,12 @@
 
 (&&) :: Bool -> Bool -> Bool
 {-# INLINE (&&) #-}
-False && x = False
+False && _ = False
 True && x = x
 
 (||) :: Bool -> Bool -> Bool
 {-# INLINE (||) #-}
-True || x = True
+True || _ = True
 False || x = x
 
 
diff --git a/Data/Vector/Mutable.hs b/Data/Vector/Mutable.hs
--- a/Data/Vector/Mutable.hs
+++ b/Data/Vector/Mutable.hs
@@ -1,5 +1,4 @@
-{-# LANGUAGE MultiParamTypeClasses, FlexibleInstances, BangPatterns,
-             TypeFamilies  #-}
+{-# LANGUAGE CPP, DeriveDataTypeable, MultiParamTypeClasses, FlexibleInstances, BangPatterns, TypeFamilies #-}
 
 -- |
 -- Module      : Data.Vector.Mutable
@@ -9,7 +8,7 @@
 -- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
 -- Stability   : experimental
 -- Portability : non-portable
--- 
+--
 -- Mutable boxed vectors.
 --
 
@@ -41,8 +40,8 @@
   clear,
 
   -- * Accessing individual elements
-  read, write, swap,
-  unsafeRead, unsafeWrite, unsafeSwap,
+  read, write, modify, swap,
+  unsafeRead, unsafeWrite, unsafeModify, unsafeSwap,
 
   -- * Modifying vectors
 
@@ -55,8 +54,6 @@
 import           Data.Primitive.Array
 import           Control.Monad.Primitive
 
-import Control.DeepSeq ( NFData, rnf )
-
 import Prelude hiding ( length, null, replicate, reverse, map, read,
                         take, drop, splitAt, init, tail )
 
@@ -88,7 +85,7 @@
   basicLength (MVector _ n _) = n
 
   {-# INLINE basicUnsafeSlice #-}
-  basicUnsafeSlice j m (MVector i n arr) = MVector (i+j) m arr
+  basicUnsafeSlice j m (MVector i _ arr) = MVector (i+j) m arr
 
   {-# INLINE basicOverlaps #-}
   basicOverlaps (MVector i m arr1) (MVector j n arr2)
@@ -103,6 +100,10 @@
         arr <- newArray n uninitialised
         return (MVector 0 n arr)
 
+  {-# INLINE basicInitialize #-}
+  -- initialization is unnecessary for boxed vectors
+  basicInitialize _ = return ()
+
   {-# INLINE basicUnsafeReplicate #-}
   basicUnsafeReplicate n x
     = do
@@ -110,15 +111,15 @@
         return (MVector 0 n arr)
 
   {-# INLINE basicUnsafeRead #-}
-  basicUnsafeRead (MVector i n arr) j = readArray arr (i+j)
+  basicUnsafeRead (MVector i _ arr) j = readArray arr (i+j)
 
   {-# INLINE basicUnsafeWrite #-}
-  basicUnsafeWrite (MVector i n arr) j x = writeArray arr (i+j) x
+  basicUnsafeWrite (MVector i _ arr) j x = writeArray arr (i+j) x
 
   {-# INLINE basicUnsafeCopy #-}
   basicUnsafeCopy (MVector i n dst) (MVector j _ src)
     = copyMutableArray dst i src j n
-  
+
   basicUnsafeMove dst@(MVector iDst n arrDst) src@(MVector iSrc _ arrSrc)
     = case n of
         0 -> return ()
@@ -254,7 +255,7 @@
 -- Overlapping
 -- -----------
 
--- Check whether two vectors overlap.
+-- | Check whether two vectors overlap.
 overlaps :: MVector s a -> MVector s a -> Bool
 {-# INLINE overlaps #-}
 overlaps = G.overlaps
@@ -310,7 +311,7 @@
 -- ------------------------
 
 -- | Reset all elements of the vector to some undefined value, clearing all
--- references to external objects. This is usually a noop for unboxed vectors. 
+-- references to external objects. This is usually a noop for unboxed vectors.
 clear :: PrimMonad m => MVector (PrimState m) a -> m ()
 {-# INLINE clear #-}
 clear = G.clear
@@ -328,6 +329,11 @@
 {-# INLINE write #-}
 write = G.write
 
+-- | Modify the element at the given position.
+modify :: PrimMonad m => MVector (PrimState m) a -> (a -> a) -> Int -> m ()
+{-# INLINE modify #-}
+modify = G.modify
+
 -- | Swap the elements at the given positions.
 swap :: PrimMonad m => MVector (PrimState m) a -> Int -> Int -> m ()
 {-# INLINE swap #-}
@@ -344,6 +350,11 @@
 {-# INLINE unsafeWrite #-}
 unsafeWrite = G.unsafeWrite
 
+-- | Modify the element at the given position. No bounds checks are performed.
+unsafeModify :: PrimMonad m => MVector (PrimState m) a -> (a -> a) -> Int -> m ()
+{-# INLINE unsafeModify #-}
+unsafeModify = G.unsafeModify
+
 -- | Swap the elements at the given positions. No bounds checks are performed.
 unsafeSwap :: PrimMonad m => MVector (PrimState m) a -> Int -> Int -> m ()
 {-# INLINE unsafeSwap #-}
@@ -374,7 +385,7 @@
 
 -- | Move the contents of a vector. The two vectors must have the same
 -- length.
--- 
+--
 -- If the vectors do not overlap, then this is equivalent to 'copy'.
 -- Otherwise, the copying is performed as if the source vector were
 -- copied to a temporary vector and then the temporary vector was copied
@@ -386,7 +397,7 @@
 
 -- | Move the contents of a vector. The two vectors must have the same
 -- length, but this is not checked.
--- 
+--
 -- If the vectors do not overlap, then this is equivalent to 'unsafeCopy'.
 -- Otherwise, the copying is performed as if the source vector were
 -- copied to a temporary vector and then the temporary vector was copied
diff --git a/Data/Vector/Primitive.hs b/Data/Vector/Primitive.hs
--- a/Data/Vector/Primitive.hs
+++ b/Data/Vector/Primitive.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE FlexibleInstances, MultiParamTypeClasses, TypeFamilies, ScopedTypeVariables, Rank2Types #-}
+{-# LANGUAGE CPP, DeriveDataTypeable, FlexibleInstances, MultiParamTypeClasses, TypeFamilies, ScopedTypeVariables, Rank2Types #-}
 
 -- |
 -- Module      : Data.Vector.Primitive
@@ -8,7 +8,7 @@
 -- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
 -- Stability   : experimental
 -- Portability : non-portable
--- 
+--
 -- Unboxed vectors of primitive types. The use of this module is not
 -- recommended except in very special cases. Adaptive unboxed vectors defined
 -- in "Data.Vector.Unboxed" are significantly more flexible at no performance
@@ -67,7 +67,7 @@
   accum, accumulate_,
   unsafeAccum, unsafeAccumulate_,
 
-  -- ** Permutations 
+  -- ** Permutations
   reverse, backpermute, unsafeBackpermute,
 
   -- ** Safe destructive updates
@@ -136,7 +136,7 @@
 
 import qualified Data.Vector.Generic           as G
 import           Data.Vector.Primitive.Mutable ( MVector(..) )
-import qualified Data.Vector.Fusion.Stream as Stream
+import qualified Data.Vector.Fusion.Bundle as Bundle
 import           Data.Primitive.ByteArray
 import           Data.Primitive ( Prim, sizeOf )
 
@@ -160,8 +160,6 @@
                         enumFromTo, enumFromThenTo,
                         mapM, mapM_ )
 
-import qualified Prelude
-
 import Data.Typeable ( Typeable )
 import Data.Data     ( Data(..) )
 import Text.Read     ( Read(..), readListPrecDefault )
@@ -228,27 +226,27 @@
 -- See http://trac.haskell.org/vector/ticket/12
 instance (Prim a, Eq a) => Eq (Vector a) where
   {-# INLINE (==) #-}
-  xs == ys = Stream.eq (G.stream xs) (G.stream ys)
+  xs == ys = Bundle.eq (G.stream xs) (G.stream ys)
 
   {-# INLINE (/=) #-}
-  xs /= ys = not (Stream.eq (G.stream xs) (G.stream ys))
+  xs /= ys = not (Bundle.eq (G.stream xs) (G.stream ys))
 
 -- See http://trac.haskell.org/vector/ticket/12
 instance (Prim a, Ord a) => Ord (Vector a) where
   {-# INLINE compare #-}
-  compare xs ys = Stream.cmp (G.stream xs) (G.stream ys)
+  compare xs ys = Bundle.cmp (G.stream xs) (G.stream ys)
 
   {-# INLINE (<) #-}
-  xs < ys = Stream.cmp (G.stream xs) (G.stream ys) == LT
+  xs < ys = Bundle.cmp (G.stream xs) (G.stream ys) == LT
 
   {-# INLINE (<=) #-}
-  xs <= ys = Stream.cmp (G.stream xs) (G.stream ys) /= GT
+  xs <= ys = Bundle.cmp (G.stream xs) (G.stream ys) /= GT
 
   {-# INLINE (>) #-}
-  xs > ys = Stream.cmp (G.stream xs) (G.stream ys) == GT
+  xs > ys = Bundle.cmp (G.stream xs) (G.stream ys) == GT
 
   {-# INLINE (>=) #-}
-  xs >= ys = Stream.cmp (G.stream xs) (G.stream ys) /= LT
+  xs >= ys = Bundle.cmp (G.stream xs) (G.stream ys) /= LT
 
 instance Prim a => Monoid (Vector a) where
   {-# INLINE mempty #-}
@@ -634,7 +632,7 @@
 -- > <5,9,2,7> // [(2,1),(0,3),(2,8)] = <3,9,8,7>
 --
 (//) :: Prim a => Vector a   -- ^ initial vector (of length @m@)
-                -> [(Int, a)] -- ^ list of index/value pairs (of length @n@) 
+                -> [(Int, a)] -- ^ list of index/value pairs (of length @n@)
                 -> Vector a
 {-# INLINE (//) #-}
 (//) = (G.//)
@@ -1208,7 +1206,7 @@
 -- >         yi = f y(i-1) x(i-1)
 --
 -- Example: @scanl (+) 0 \<1,2,3,4\> = \<0,1,3,6,10\>@
--- 
+--
 scanl :: (Prim a, Prim b) => (a -> b -> a) -> a -> Vector b -> Vector a
 {-# INLINE scanl #-}
 scanl = G.scanl
@@ -1332,7 +1330,7 @@
   :: (Prim a, PrimMonad m) => MVector (PrimState m) a -> Vector a -> m ()
 {-# INLINE unsafeCopy #-}
 unsafeCopy = G.unsafeCopy
-           
+
 -- | /O(n)/ Copy an immutable vector into a mutable one. The two vectors must
 -- have the same length.
 copy :: (Prim a, PrimMonad m) => MVector (PrimState m) a -> Vector a -> m ()
diff --git a/Data/Vector/Primitive/Mutable.hs b/Data/Vector/Primitive/Mutable.hs
--- a/Data/Vector/Primitive/Mutable.hs
+++ b/Data/Vector/Primitive/Mutable.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE MultiParamTypeClasses, FlexibleInstances, ScopedTypeVariables #-}
+{-# LANGUAGE CPP, DeriveDataTypeable, MultiParamTypeClasses, FlexibleInstances, ScopedTypeVariables #-}
 
 -- |
 -- Module      : Data.Vector.Primitive.Mutable
@@ -8,7 +8,7 @@
 -- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
 -- Stability   : experimental
 -- Portability : non-portable
--- 
+--
 -- Mutable primitive vectors.
 --
 
@@ -40,8 +40,8 @@
   clear,
 
   -- * Accessing individual elements
-  read, write, swap,
-  unsafeRead, unsafeWrite, unsafeSwap,
+  read, write, modify, swap,
+  unsafeRead, unsafeWrite, unsafeModify, unsafeSwap,
 
   -- * Modifying vectors
 
@@ -52,6 +52,7 @@
 import qualified Data.Vector.Generic.Mutable as G
 import           Data.Primitive.ByteArray
 import           Data.Primitive ( Prim, sizeOf )
+import           Data.Word ( Word8 )
 import           Control.Monad.Primitive
 import           Control.Monad ( liftM )
 
@@ -62,6 +63,8 @@
 
 import Data.Typeable ( Typeable )
 
+-- Data.Vector.Internal.Check is unnecessary
+#define NOT_VECTOR_MODULE
 #include "vector.h"
 
 -- | Mutable vectors of primitive types.
@@ -78,7 +81,7 @@
 
 instance Prim a => G.MVector MVector a where
   basicLength (MVector _ n _) = n
-  basicUnsafeSlice j m (MVector i n arr)
+  basicUnsafeSlice j m (MVector i _ arr)
     = MVector (i+j) m arr
 
   {-# INLINE basicOverlaps #-}
@@ -89,21 +92,33 @@
       between x y z = x >= y && x < z
 
   {-# INLINE basicUnsafeNew #-}
-  basicUnsafeNew n = MVector 0 n
-                     `liftM` newByteArray (n * sizeOf (undefined :: a))
+  basicUnsafeNew n
+    | n < 0 = error $ "Primitive.basicUnsafeNew: negative length: " ++ show n
+    | n > mx = error $ "Primitive.basicUnsafeNew: length to large: " ++ show n
+    | otherwise = MVector 0 n `liftM` newByteArray (n * size)
+    where
+      size = sizeOf (undefined :: a)
+      mx = maxBound `div` size :: Int
 
+  {-# INLINE basicInitialize #-}
+  basicInitialize (MVector off n v) =
+      setByteArray v (off * size) (n * size) (0 :: Word8)
+    where
+      size = sizeOf (undefined :: a)
+
+
   {-# INLINE basicUnsafeRead #-}
-  basicUnsafeRead (MVector i n arr) j = readByteArray arr (i+j)
+  basicUnsafeRead (MVector i _ arr) j = readByteArray arr (i+j)
 
   {-# INLINE basicUnsafeWrite #-}
-  basicUnsafeWrite (MVector i n arr) j x = writeByteArray arr (i+j) x
+  basicUnsafeWrite (MVector i _ arr) j x = writeByteArray arr (i+j) x
 
   {-# INLINE basicUnsafeCopy #-}
   basicUnsafeCopy (MVector i n dst) (MVector j _ src)
     = copyMutableByteArray dst (i*sz) src (j*sz) (n*sz)
     where
       sz = sizeOf (undefined :: a)
-  
+
   {-# INLINE basicUnsafeMove #-}
   basicUnsafeMove (MVector i n dst) (MVector j _ src)
     = moveByteArray dst (i*sz) src (j*sz) (n * sz)
@@ -183,7 +198,7 @@
 -- Overlapping
 -- -----------
 
--- Check whether two vectors overlap.
+-- | Check whether two vectors overlap.
 overlaps :: Prim a => MVector s a -> MVector s a -> Bool
 {-# INLINE overlaps #-}
 overlaps = G.overlaps
@@ -224,7 +239,7 @@
 
 -- | Grow a vector by the given number of elements. The number must be
 -- positive.
-grow :: (PrimMonad m, Prim a)  
+grow :: (PrimMonad m, Prim a)
               => MVector (PrimState m) a -> Int -> m (MVector (PrimState m) a)
 {-# INLINE grow #-}
 grow = G.grow
@@ -240,7 +255,7 @@
 -- ------------------------
 
 -- | Reset all elements of the vector to some undefined value, clearing all
--- references to external objects. This is usually a noop for unboxed vectors. 
+-- references to external objects. This is usually a noop for unboxed vectors.
 clear :: (PrimMonad m, Prim a) => MVector (PrimState m) a -> m ()
 {-# INLINE clear #-}
 clear = G.clear
@@ -258,6 +273,11 @@
 {-# INLINE write #-}
 write = G.write
 
+-- | Modify the element at the given position.
+modify :: (PrimMonad m, Prim a) => MVector (PrimState m) a -> (a -> a) -> Int -> m ()
+{-# INLINE modify #-}
+modify = G.modify
+
 -- | Swap the elements at the given positions.
 swap :: (PrimMonad m, Prim a) => MVector (PrimState m) a -> Int -> Int -> m ()
 {-# INLINE swap #-}
@@ -275,6 +295,11 @@
 {-# INLINE unsafeWrite #-}
 unsafeWrite = G.unsafeWrite
 
+-- | Modify the element at the given position. No bounds checks are performed.
+unsafeModify :: (PrimMonad m, Prim a) => MVector (PrimState m) a -> (a -> a) -> Int -> m ()
+{-# INLINE unsafeModify #-}
+unsafeModify = G.unsafeModify
+
 -- | Swap the elements at the given positions. No bounds checks are performed.
 unsafeSwap
     :: (PrimMonad m, Prim a) => MVector (PrimState m) a -> Int -> Int -> m ()
@@ -291,7 +316,7 @@
 
 -- | Copy a vector. The two vectors must have the same length and may not
 -- overlap.
-copy :: (PrimMonad m, Prim a) 
+copy :: (PrimMonad m, Prim a)
                  => MVector (PrimState m) a -> MVector (PrimState m) a -> m ()
 {-# INLINE copy #-}
 copy = G.copy
@@ -307,7 +332,7 @@
 
 -- | Move the contents of a vector. The two vectors must have the same
 -- length.
--- 
+--
 -- If the vectors do not overlap, then this is equivalent to 'copy'.
 -- Otherwise, the copying is performed as if the source vector were
 -- copied to a temporary vector and then the temporary vector was copied
@@ -319,7 +344,7 @@
 
 -- | Move the contents of a vector. The two vectors must have the same
 -- length, but this is not checked.
--- 
+--
 -- If the vectors do not overlap, then this is equivalent to 'unsafeCopy'.
 -- Otherwise, the copying is performed as if the source vector were
 -- copied to a temporary vector and then the temporary vector was copied
diff --git a/Data/Vector/Storable.hs b/Data/Vector/Storable.hs
--- a/Data/Vector/Storable.hs
+++ b/Data/Vector/Storable.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE MultiParamTypeClasses, FlexibleInstances, TypeFamilies, Rank2Types, ScopedTypeVariables #-}
+{-# LANGUAGE CPP, DeriveDataTypeable, MultiParamTypeClasses, FlexibleInstances, TypeFamilies, Rank2Types, ScopedTypeVariables #-}
 
 -- |
 -- Module      : Data.Vector.Storable
@@ -8,7 +8,7 @@
 -- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
 -- Stability   : experimental
 -- Portability : non-portable
--- 
+--
 -- 'Storable'-based vectors.
 --
 
@@ -64,7 +64,7 @@
   accum, accumulate_,
   unsafeAccum, unsafeAccumulate_,
 
-  -- ** Permutations 
+  -- ** Permutations
   reverse, backpermute, unsafeBackpermute,
 
   -- ** Safe destructive updates
@@ -139,7 +139,7 @@
 import qualified Data.Vector.Generic          as G
 import           Data.Vector.Storable.Mutable ( MVector(..) )
 import Data.Vector.Storable.Internal
-import qualified Data.Vector.Fusion.Stream as Stream
+import qualified Data.Vector.Fusion.Bundle as Bundle
 
 import Foreign.Storable
 import Foreign.ForeignPtr
@@ -165,8 +165,6 @@
                         enumFromTo, enumFromThenTo,
                         mapM, mapM_ )
 
-import qualified Prelude
-
 import Data.Typeable ( Typeable )
 import Data.Data     ( Data(..) )
 import Text.Read     ( Read(..), readListPrecDefault )
@@ -177,6 +175,8 @@
 import qualified GHC.Exts as Exts
 #endif
 
+-- Data.Vector.Internal.Check is unused
+#define NOT_VECTOR_MODULE
 #include "vector.h"
 
 -- | 'Storable'-based vectors
@@ -235,27 +235,27 @@
 -- See http://trac.haskell.org/vector/ticket/12
 instance (Storable a, Eq a) => Eq (Vector a) where
   {-# INLINE (==) #-}
-  xs == ys = Stream.eq (G.stream xs) (G.stream ys)
+  xs == ys = Bundle.eq (G.stream xs) (G.stream ys)
 
   {-# INLINE (/=) #-}
-  xs /= ys = not (Stream.eq (G.stream xs) (G.stream ys))
+  xs /= ys = not (Bundle.eq (G.stream xs) (G.stream ys))
 
 -- See http://trac.haskell.org/vector/ticket/12
 instance (Storable a, Ord a) => Ord (Vector a) where
   {-# INLINE compare #-}
-  compare xs ys = Stream.cmp (G.stream xs) (G.stream ys)
+  compare xs ys = Bundle.cmp (G.stream xs) (G.stream ys)
 
   {-# INLINE (<) #-}
-  xs < ys = Stream.cmp (G.stream xs) (G.stream ys) == LT
+  xs < ys = Bundle.cmp (G.stream xs) (G.stream ys) == LT
 
   {-# INLINE (<=) #-}
-  xs <= ys = Stream.cmp (G.stream xs) (G.stream ys) /= GT
+  xs <= ys = Bundle.cmp (G.stream xs) (G.stream ys) /= GT
 
   {-# INLINE (>) #-}
-  xs > ys = Stream.cmp (G.stream xs) (G.stream ys) == GT
+  xs > ys = Bundle.cmp (G.stream xs) (G.stream ys) == GT
 
   {-# INLINE (>=) #-}
-  xs >= ys = Stream.cmp (G.stream xs) (G.stream ys) /= LT
+  xs >= ys = Bundle.cmp (G.stream xs) (G.stream ys) /= LT
 
 instance Storable a => Monoid (Vector a) where
   {-# INLINE mempty #-}
@@ -642,7 +642,7 @@
 -- > <5,9,2,7> // [(2,1),(0,3),(2,8)] = <3,9,8,7>
 --
 (//) :: Storable a => Vector a   -- ^ initial vector (of length @m@)
-                -> [(Int, a)] -- ^ list of index/value pairs (of length @n@) 
+                -> [(Int, a)] -- ^ list of index/value pairs (of length @n@)
                 -> Vector a
 {-# INLINE (//) #-}
 (//) = (G.//)
@@ -1226,7 +1226,7 @@
 -- >         yi = f y(i-1) x(i-1)
 --
 -- Example: @scanl (+) 0 \<1,2,3,4\> = \<0,1,3,6,10\>@
--- 
+--
 scanl :: (Storable a, Storable b) => (a -> b -> a) -> a -> Vector b -> Vector a
 {-# INLINE scanl #-}
 scanl = G.scanl
@@ -1369,7 +1369,7 @@
   :: (Storable a, PrimMonad m) => MVector (PrimState m) a -> Vector a -> m ()
 {-# INLINE unsafeCopy #-}
 unsafeCopy = G.unsafeCopy
-           
+
 -- | /O(n)/ Copy an immutable vector into a mutable one. The two vectors must
 -- have the same length.
 copy :: (Storable a, PrimMonad m) => MVector (PrimState m) a -> Vector a -> m ()
@@ -1389,16 +1389,16 @@
                      -> Int             -- ^ offset
                      -> Int             -- ^ length
                      -> Vector a
-{-# INLINE unsafeFromForeignPtr #-}
+{-# INLINE_FUSED unsafeFromForeignPtr #-}
 unsafeFromForeignPtr fp i n = unsafeFromForeignPtr0 fp' n
     where
       fp' = updPtr (`advancePtr` i) fp
 
 {-# RULES
 "unsafeFromForeignPtr fp 0 n -> unsafeFromForeignPtr0 fp n " forall fp n.
-  unsafeFromForeignPtr fp 0 n = unsafeFromForeignPtr0 fp n
-  #-}
+  unsafeFromForeignPtr fp 0 n = unsafeFromForeignPtr0 fp n   #-}
 
+
 -- | /O(1)/ Create a vector from a 'ForeignPtr' and a length.
 --
 -- It is assumed the pointer points directly to the data (no offset).
@@ -1431,6 +1431,6 @@
 -- modified through the 'Ptr.
 unsafeWith :: Storable a => Vector a -> (Ptr a -> IO b) -> IO b
 {-# INLINE unsafeWith #-}
-unsafeWith (Vector n fp) = withForeignPtr fp
+unsafeWith (Vector _ fp) = withForeignPtr fp
 
 
diff --git a/Data/Vector/Storable/Internal.hs b/Data/Vector/Storable/Internal.hs
--- a/Data/Vector/Storable/Internal.hs
+++ b/Data/Vector/Storable/Internal.hs
@@ -6,7 +6,7 @@
 -- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
 -- Stability   : experimental
 -- Portability : non-portable
--- 
+--
 -- Ugly internal utility functions for implementing 'Storable'-based vectors.
 --
 
@@ -14,12 +14,8 @@
   getPtr, setPtr, updPtr
 ) where
 
-import Control.Monad.Primitive ( unsafeInlineIO )
-import Foreign.Storable
 import Foreign.ForeignPtr
 import Foreign.Ptr
-import Foreign.Marshal.Array ( advancePtr )
-import GHC.Base         ( quotInt )
 import GHC.ForeignPtr   ( ForeignPtr(..) )
 import GHC.Ptr          ( Ptr(..) )
 
diff --git a/Data/Vector/Storable/Mutable.hs b/Data/Vector/Storable/Mutable.hs
--- a/Data/Vector/Storable/Mutable.hs
+++ b/Data/Vector/Storable/Mutable.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE MultiParamTypeClasses, FlexibleInstances, ScopedTypeVariables #-}
+{-# LANGUAGE CPP, DeriveDataTypeable, MultiParamTypeClasses, FlexibleInstances, ScopedTypeVariables #-}
 
 -- |
 -- Module      : Data.Vector.Storable.Mutable
@@ -8,7 +8,7 @@
 -- Maintainer  : Roman Leshchinskiy <rl@cse.unsw.edu.au>
 -- Stability   : experimental
 -- Portability : non-portable
--- 
+--
 -- Mutable vectors based on Storable.
 --
 
@@ -40,8 +40,8 @@
   clear,
 
   -- * Accessing individual elements
-  read, write, swap,
-  unsafeRead, unsafeWrite, unsafeSwap,
+  read, write, modify, swap,
+  unsafeRead, unsafeWrite, unsafeModify, unsafeSwap,
 
   -- * Modifying vectors
 
@@ -71,7 +71,6 @@
 
 import Foreign.Ptr
 import Foreign.Marshal.Array ( advancePtr, copyArray, moveArray )
-import Foreign.C.Types ( CInt )
 
 import Control.Monad.Primitive
 import Data.Primitive.Addr
@@ -85,6 +84,8 @@
 
 import Data.Typeable ( Typeable )
 
+-- Data.Vector.Internal.Check is not needed
+#define NOT_VECTOR_MODULE
 #include "vector.h"
 
 -- | Mutable 'Storable'-based vectors
@@ -103,7 +104,7 @@
   basicLength (MVector n _) = n
 
   {-# INLINE basicUnsafeSlice #-}
-  basicUnsafeSlice j m (MVector n fp) = MVector m (updPtr (`advancePtr` j) fp)
+  basicUnsafeSlice j m (MVector _ fp) = MVector m (updPtr (`advancePtr` j) fp)
 
   -- FIXME: this relies on non-portable pointer comparisons
   {-# INLINE basicOverlaps #-}
@@ -116,11 +117,18 @@
 
   {-# INLINE basicUnsafeNew #-}
   basicUnsafeNew n
-    = unsafePrimToPrim
-    $ do
+    | n < 0 = error $ "Storable.basicUnsafeNew: negative length: " ++ show n
+    | n > mx = error $ "Storable.basicUnsafeNew: length too large: " ++ show n
+    | otherwise = unsafePrimToPrim $ do
         fp <- mallocVector n
         return $ MVector n fp
+    where
+      size = sizeOf (undefined :: a)
+      mx = maxBound `quot` size :: Int
 
+  {-# INLINE basicInitialize #-}
+  basicInitialize = storableZero
+
   {-# INLINE basicUnsafeRead #-}
   basicUnsafeRead (MVector _ fp) i
     = unsafePrimToPrim
@@ -140,7 +148,7 @@
     $ withForeignPtr fp $ \p ->
       withForeignPtr fq $ \q ->
       copyArray p q n
-  
+
   {-# INLINE basicUnsafeMove #-}
   basicUnsafeMove (MVector n fp) (MVector _ fq)
     = unsafePrimToPrim
@@ -148,9 +156,21 @@
       withForeignPtr fq $ \q ->
       moveArray p q n
 
+storableZero :: forall a m. (Storable a, PrimMonad m) => MVector (PrimState m) a -> m ()
+{-# INLINE storableZero #-}
+storableZero (MVector n fp) = unsafePrimToPrim . withForeignPtr fp $ \(Ptr p) -> do
+  let q = Addr p
+  setAddr q byteSize (0 :: Word8)
+ where
+ x :: a
+ x = undefined
+
+ byteSize :: Int
+ byteSize = n * sizeOf x
+
 storableSet :: (Storable a, PrimMonad m) => MVector (PrimState m) a -> a -> m ()
 {-# INLINE storableSet #-}
-storableSet v@(MVector n fp) x
+storableSet (MVector n fp) x
   | n == 0 = return ()
   | otherwise = unsafePrimToPrim $
                 case sizeOf x of
@@ -260,7 +280,7 @@
 -- Overlapping
 -- -----------
 
--- Check whether two vectors overlap.
+-- | Check whether two vectors overlap.
 overlaps :: Storable a => MVector s a -> MVector s a -> Bool
 {-# INLINE overlaps #-}
 overlaps = G.overlaps
@@ -301,7 +321,7 @@
 
 -- | Grow a vector by the given number of elements. The number must be
 -- positive.
-grow :: (PrimMonad m, Storable a)  
+grow :: (PrimMonad m, Storable a)
               => MVector (PrimState m) a -> Int -> m (MVector (PrimState m) a)
 {-# INLINE grow #-}
 grow = G.grow
@@ -317,7 +337,7 @@
 -- ------------------------
 
 -- | Reset all elements of the vector to some undefined value, clearing all
--- references to external objects. This is usually a noop for unboxed vectors. 
+-- references to external objects. This is usually a noop for unboxed vectors.
 clear :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> m ()
 {-# INLINE clear #-}
 clear = G.clear
@@ -336,6 +356,11 @@
 {-# INLINE write #-}
 write = G.write
 
+-- | Modify the element at the given position.
+modify :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> (a -> a) -> Int -> m ()
+{-# INLINE modify #-}
+modify = G.modify
+
 -- | Swap the elements at the given positions.
 swap
     :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> Int -> m ()
@@ -354,6 +379,11 @@
 {-# INLINE unsafeWrite #-}
 unsafeWrite = G.unsafeWrite
 
+-- | Modify the element at the given position. No bounds checks are performed.
+unsafeModify :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> (a -> a) -> Int -> m ()
+{-# INLINE unsafeModify #-}
+unsafeModify = G.unsafeModify
+
 -- | Swap the elements at the given positions. No bounds checks are performed.
 unsafeSwap
     :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> Int -> m ()
@@ -370,7 +400,7 @@
 
 -- | Copy a vector. The two vectors must have the same length and may not
 -- overlap.
-copy :: (PrimMonad m, Storable a) 
+copy :: (PrimMonad m, Storable a)
                  => MVector (PrimState m) a -> MVector (PrimState m) a -> m ()
 {-# INLINE copy #-}
 copy = G.copy
@@ -386,7 +416,7 @@
 
 -- | Move the contents of a vector. The two vectors must have the same
 -- length.
--- 
+--
 -- If the vectors do not overlap, then this is equivalent to 'copy'.
 -- Otherwise, the copying is performed as if the source vector were
 -- copied to a temporary vector and then the temporary vector was copied
@@ -398,7 +428,7 @@
 
 -- | Move the contents of a vector. The two vectors must have the same
 -- length, but this is not checked.
--- 
+--
 -- If the vectors do not overlap, then this is equivalent to 'unsafeCopy'.
 -- Otherwise, the copying is performed as if the source vector were
 -- copied to a temporary vector and then the temporary vector was copied
@@ -441,16 +471,16 @@
                      -> Int             -- ^ offset
                      -> Int             -- ^ length
                      -> MVector s a
-{-# INLINE unsafeFromForeignPtr #-}
+{-# INLINE_FUSED unsafeFromForeignPtr #-}
 unsafeFromForeignPtr fp i n = unsafeFromForeignPtr0 fp' n
     where
       fp' = updPtr (`advancePtr` i) fp
 
 {-# RULES
 "unsafeFromForeignPtr fp 0 n -> unsafeFromForeignPtr0 fp n " forall fp n.
-  unsafeFromForeignPtr fp 0 n = unsafeFromForeignPtr0 fp n
-  #-}
+  unsafeFromForeignPtr fp 0 n = unsafeFromForeignPtr0 fp n   #-}
 
+
 -- | /O(1)/ Create a mutable vector from a 'ForeignPtr' and a length.
 --
 -- It is assumed the pointer points directly to the data (no offset).
@@ -487,5 +517,5 @@
 -- the modification.
 unsafeWith :: Storable a => IOVector a -> (Ptr a -> IO b) -> IO b
 {-# INLINE unsafeWith #-}
-unsafeWith (MVector n fp) = withForeignPtr fp
+unsafeWith (MVector _ fp) = withForeignPtr fp
 
diff --git a/Data/Vector/Unboxed.hs b/Data/Vector/Unboxed.hs
--- a/Data/Vector/Unboxed.hs
+++ b/Data/Vector/Unboxed.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE Rank2Types, TypeFamilies #-}
+{-# LANGUAGE CPP, Rank2Types, TypeFamilies #-}
 
 -- |
 -- Module      : Data.Vector.Unboxed
@@ -87,7 +87,7 @@
   accum, accumulate, accumulate_,
   unsafeAccum, unsafeAccumulate, unsafeAccumulate_,
 
-  -- ** Permutations 
+  -- ** Permutations
   reverse, backpermute, unsafeBackpermute,
 
   -- ** Safe destructive updates
@@ -102,7 +102,7 @@
   map, imap, concatMap,
 
   -- ** Monadic mapping
-  mapM, mapM_, forM, forM_,
+  mapM, imapM, mapM_, imapM_, forM, forM_,
 
   -- ** Zipping
   zipWith, zipWith3, zipWith4, zipWith5, zipWith6,
@@ -110,7 +110,7 @@
   zip, zip3, zip4, zip5, zip6,
 
   -- ** Monadic zipping
-  zipWithM, zipWithM_,
+  zipWithM, izipWithM, zipWithM_, izipWithM_,
 
   -- ** Unzipping
   unzip, unzip3, unzip4, unzip5, unzip6,
@@ -138,8 +138,9 @@
   minIndex, minIndexBy, maxIndex, maxIndexBy,
 
   -- ** Monadic folds
-  foldM, foldM', fold1M, fold1M',
-  foldM_, foldM'_, fold1M_, fold1M'_,
+  foldM, ifoldM, foldM', ifoldM',
+  fold1M, fold1M', foldM_, ifoldM_,
+  foldM'_, ifoldM'_, fold1M_, fold1M'_,
 
   -- * Prefix sums (scans)
   prescanl, prescanl',
@@ -163,7 +164,7 @@
 
 import Data.Vector.Unboxed.Base
 import qualified Data.Vector.Generic as G
-import qualified Data.Vector.Fusion.Stream as Stream
+import qualified Data.Vector.Fusion.Bundle as Bundle
 import Data.Vector.Fusion.Util ( delayed_min )
 
 import Control.Monad.ST ( ST )
@@ -182,7 +183,6 @@
                         scanl, scanl1, scanr, scanr1,
                         enumFromTo, enumFromThenTo,
                         mapM, mapM_ )
-import qualified Prelude
 
 import Text.Read     ( Read(..), readListPrecDefault )
 
@@ -192,32 +192,33 @@
 import qualified GHC.Exts as Exts (IsList(..))
 #endif
 
+#define NOT_VECTOR_MODULE
 #include "vector.h"
 
 -- See http://trac.haskell.org/vector/ticket/12
 instance (Unbox a, Eq a) => Eq (Vector a) where
   {-# INLINE (==) #-}
-  xs == ys = Stream.eq (G.stream xs) (G.stream ys)
+  xs == ys = Bundle.eq (G.stream xs) (G.stream ys)
 
   {-# INLINE (/=) #-}
-  xs /= ys = not (Stream.eq (G.stream xs) (G.stream ys))
+  xs /= ys = not (Bundle.eq (G.stream xs) (G.stream ys))
 
 -- See http://trac.haskell.org/vector/ticket/12
 instance (Unbox a, Ord a) => Ord (Vector a) where
   {-# INLINE compare #-}
-  compare xs ys = Stream.cmp (G.stream xs) (G.stream ys)
+  compare xs ys = Bundle.cmp (G.stream xs) (G.stream ys)
 
   {-# INLINE (<) #-}
-  xs < ys = Stream.cmp (G.stream xs) (G.stream ys) == LT
+  xs < ys = Bundle.cmp (G.stream xs) (G.stream ys) == LT
 
   {-# INLINE (<=) #-}
-  xs <= ys = Stream.cmp (G.stream xs) (G.stream ys) /= GT
+  xs <= ys = Bundle.cmp (G.stream xs) (G.stream ys) /= GT
 
   {-# INLINE (>) #-}
-  xs > ys = Stream.cmp (G.stream xs) (G.stream ys) == GT
+  xs > ys = Bundle.cmp (G.stream xs) (G.stream ys) == GT
 
   {-# INLINE (>=) #-}
-  xs >= ys = Stream.cmp (G.stream xs) (G.stream ys) /= LT
+  xs >= ys = Bundle.cmp (G.stream xs) (G.stream ys) /= LT
 
 instance Unbox a => Monoid (Vector a) where
   {-# INLINE mempty #-}
@@ -610,7 +611,7 @@
 -- > <5,9,2,7> // [(2,1),(0,3),(2,8)] = <3,9,8,7>
 --
 (//) :: Unbox a => Vector a   -- ^ initial vector (of length @m@)
-                -> [(Int, a)] -- ^ list of index/value pairs (of length @n@) 
+                -> [(Int, a)] -- ^ list of index/value pairs (of length @n@)
                 -> Vector a
 {-# INLINE (//) #-}
 (//) = (G.//)
@@ -799,12 +800,25 @@
 {-# INLINE mapM #-}
 mapM = G.mapM
 
+-- | /O(n)/ Apply the monadic action to every element of a vector and its
+-- index, yielding a vector of results
+imapM :: (Monad m, Unbox a, Unbox b)
+      => (Int -> a -> m b) -> Vector a -> m (Vector b)
+{-# INLINE imapM #-}
+imapM = G.imapM
+
 -- | /O(n)/ Apply the monadic action to all elements of a vector and ignore the
 -- results
 mapM_ :: (Monad m, Unbox a) => (a -> m b) -> Vector a -> m ()
 {-# INLINE mapM_ #-}
 mapM_ = G.mapM_
 
+-- | /O(n)/ Apply the monadic action to every element of a vector and its
+-- index, ignoring the results
+imapM_ :: (Monad m, Unbox a) => (Int -> a -> m b) -> Vector a -> m ()
+{-# INLINE imapM_ #-}
+imapM_ = G.imapM_
+
 -- | /O(n)/ Apply the monadic action to all elements of the vector, yielding a
 -- vector of results. Equvalent to @flip 'mapM'@.
 forM :: (Monad m, Unbox a, Unbox b) => Vector a -> (a -> m b) -> m (Vector b)
@@ -896,6 +910,13 @@
 {-# INLINE zipWithM #-}
 zipWithM = G.zipWithM
 
+-- | /O(min(m,n))/ Zip the two vectors with a monadic action that also takes
+-- the element index and yield a vector of results
+izipWithM :: (Monad m, Unbox a, Unbox b, Unbox c)
+         => (Int -> a -> b -> m c) -> Vector a -> Vector b -> m (Vector c)
+{-# INLINE izipWithM #-}
+izipWithM = G.izipWithM
+
 -- | /O(min(m,n))/ Zip the two vectors with the monadic action and ignore the
 -- results
 zipWithM_ :: (Monad m, Unbox a, Unbox b)
@@ -903,6 +924,13 @@
 {-# INLINE zipWithM_ #-}
 zipWithM_ = G.zipWithM_
 
+-- | /O(min(m,n))/ Zip the two vectors with a monadic action that also takes
+-- the element index and ignore the results
+izipWithM_ :: (Monad m, Unbox a, Unbox b)
+          => (Int -> a -> b -> m c) -> Vector a -> Vector b -> m ()
+{-# INLINE izipWithM_ #-}
+izipWithM_ = G.izipWithM_
+
 -- Filtering
 -- ---------
 
@@ -1165,6 +1193,11 @@
 {-# INLINE foldM #-}
 foldM = G.foldM
 
+-- | /O(n)/ Monadic fold (action applied to each element and its index)
+ifoldM :: (Monad m, Unbox b) => (a -> Int -> b -> m a) -> a -> Vector b -> m a
+{-# INLINE ifoldM #-}
+ifoldM = G.ifoldM
+
 -- | /O(n)/ Monadic fold over non-empty vectors
 fold1M :: (Monad m, Unbox a) => (a -> a -> m a) -> Vector a -> m a
 {-# INLINE fold1M #-}
@@ -1175,6 +1208,12 @@
 {-# INLINE foldM' #-}
 foldM' = G.foldM'
 
+-- | /O(n)/ Monadic fold with strict accumulator (action applied to each
+-- element and its index)
+ifoldM' :: (Monad m, Unbox b) => (a -> Int -> b -> m a) -> a -> Vector b -> m a
+{-# INLINE ifoldM' #-}
+ifoldM' = G.ifoldM'
+
 -- | /O(n)/ Monadic fold over non-empty vectors with strict accumulator
 fold1M' :: (Monad m, Unbox a) => (a -> a -> m a) -> Vector a -> m a
 {-# INLINE fold1M' #-}
@@ -1185,6 +1224,12 @@
 {-# INLINE foldM_ #-}
 foldM_ = G.foldM_
 
+-- | /O(n)/ Monadic fold that discards the result (action applied to each
+-- element and its index)
+ifoldM_ :: (Monad m, Unbox b) => (a -> Int -> b -> m a) -> a -> Vector b -> m ()
+{-# INLINE ifoldM_ #-}
+ifoldM_ = G.ifoldM_
+
 -- | /O(n)/ Monadic fold over non-empty vectors that discards the result
 fold1M_ :: (Monad m, Unbox a) => (a -> a -> m a) -> Vector a -> m ()
 {-# INLINE fold1M_ #-}
@@ -1195,6 +1240,13 @@
 {-# INLINE foldM'_ #-}
 foldM'_ = G.foldM'_
 
+-- | /O(n)/ Monadic fold with strict accumulator that discards the result
+-- (action applied to each element and its index)
+ifoldM'_ :: (Monad m, Unbox b)
+         => (a -> Int -> b -> m a) -> a -> Vector b -> m ()
+{-# INLINE ifoldM'_ #-}
+ifoldM'_ = G.ifoldM'_
+
 -- | /O(n)/ Monadic fold over non-empty vectors with strict accumulator
 -- that discards the result
 fold1M'_ :: (Monad m, Unbox a) => (a -> a -> m a) -> Vector a -> m ()
@@ -1245,7 +1297,7 @@
 -- >         yi = f y(i-1) x(i-1)
 --
 -- Example: @scanl (+) 0 \<1,2,3,4\> = \<0,1,3,6,10\>@
--- 
+--
 scanl :: (Unbox a, Unbox b) => (a -> b -> a) -> a -> Vector b -> Vector a
 {-# INLINE scanl #-}
 scanl = G.scanl
@@ -1369,7 +1421,7 @@
   :: (Unbox a, PrimMonad m) => MVector (PrimState m) a -> Vector a -> m ()
 {-# INLINE unsafeCopy #-}
 unsafeCopy = G.unsafeCopy
-           
+
 -- | /O(n)/ Copy an immutable vector into a mutable one. The two vectors must
 -- have the same length.
 copy :: (Unbox a, PrimMonad m) => MVector (PrimState m) a -> Vector a -> m ()
diff --git a/Data/Vector/Unboxed/Base.hs b/Data/Vector/Unboxed/Base.hs
--- a/Data/Vector/Unboxed/Base.hs
+++ b/Data/Vector/Unboxed/Base.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE BangPatterns, MultiParamTypeClasses, TypeFamilies, FlexibleContexts #-}
+{-# LANGUAGE BangPatterns, CPP, MultiParamTypeClasses, TypeFamilies, FlexibleContexts #-}
 #if __GLASGOW_HASKELL__ >= 707
 {-# LANGUAGE DeriveDataTypeable, StandaloneDeriving #-}
 #endif
@@ -48,6 +48,8 @@
 
 import Data.Data     ( Data(..) )
 
+-- Data.Vector.Internal.Check is unused
+#define NOT_VECTOR_MODULE
 #include "vector.h"
 
 data family MVector s a
@@ -104,6 +106,7 @@
   {-# INLINE basicUnsafeSlice #-}
   {-# INLINE basicOverlaps #-}
   {-# INLINE basicUnsafeNew #-}
+  {-# INLINE basicInitialize #-}
   {-# INLINE basicUnsafeRead #-}
   {-# INLINE basicUnsafeWrite #-}
   {-# INLINE basicClear #-}
@@ -113,12 +116,15 @@
 
   basicLength (MV_Unit n) = n
 
-  basicUnsafeSlice i m (MV_Unit n) = MV_Unit m
+  basicUnsafeSlice _ m (MV_Unit _) = MV_Unit m
 
   basicOverlaps _ _ = False
 
   basicUnsafeNew n = return (MV_Unit n)
 
+  -- Nothing to initialize
+  basicInitialize _ = return ()
+
   basicUnsafeRead (MV_Unit _) _ = return ()
 
   basicUnsafeWrite (MV_Unit _) _ () = return ()
@@ -142,10 +148,10 @@
   basicLength (V_Unit n) = n
 
   {-# INLINE basicUnsafeSlice #-}
-  basicUnsafeSlice i m (V_Unit n) = V_Unit m
+  basicUnsafeSlice _ m (V_Unit _) = V_Unit m
 
   {-# INLINE basicUnsafeIndexM #-}
-  basicUnsafeIndexM (V_Unit _) i = return ()
+  basicUnsafeIndexM (V_Unit _) _ = return ()
 
   {-# INLINE basicUnsafeCopy #-}
   basicUnsafeCopy (MV_Unit _) (V_Unit _) = return ()
@@ -164,6 +170,7 @@
 ; {-# INLINE basicUnsafeSlice #-}                                       \
 ; {-# INLINE basicOverlaps #-}                                          \
 ; {-# INLINE basicUnsafeNew #-}                                         \
+; {-# INLINE basicInitialize #-}                                        \
 ; {-# INLINE basicUnsafeReplicate #-}                                   \
 ; {-# INLINE basicUnsafeRead #-}                                        \
 ; {-# INLINE basicUnsafeWrite #-}                                       \
@@ -175,6 +182,7 @@
 ; basicUnsafeSlice i n (con v) = con $ M.basicUnsafeSlice i n v         \
 ; basicOverlaps (con v1) (con v2) = M.basicOverlaps v1 v2               \
 ; basicUnsafeNew n = con `liftM` M.basicUnsafeNew n                     \
+; basicInitialize (con v) = M.basicInitialize v                         \
 ; basicUnsafeReplicate n x = con `liftM` M.basicUnsafeReplicate n x     \
 ; basicUnsafeRead (con v) i = M.basicUnsafeRead v i                     \
 ; basicUnsafeWrite (con v) i x = M.basicUnsafeWrite v i x               \
@@ -305,6 +313,7 @@
   {-# INLINE basicUnsafeSlice #-}
   {-# INLINE basicOverlaps #-}
   {-# INLINE basicUnsafeNew #-}
+  {-# INLINE basicInitialize #-}
   {-# INLINE basicUnsafeReplicate #-}
   {-# INLINE basicUnsafeRead #-}
   {-# INLINE basicUnsafeWrite #-}
@@ -316,6 +325,7 @@
   basicUnsafeSlice i n (MV_Bool v) = MV_Bool $ M.basicUnsafeSlice i n v
   basicOverlaps (MV_Bool v1) (MV_Bool v2) = M.basicOverlaps v1 v2
   basicUnsafeNew n = MV_Bool `liftM` M.basicUnsafeNew n
+  basicInitialize (MV_Bool v) = M.basicInitialize v
   basicUnsafeReplicate n x = MV_Bool `liftM` M.basicUnsafeReplicate n (fromBool x)
   basicUnsafeRead (MV_Bool v) i = toBool `liftM` M.basicUnsafeRead v i
   basicUnsafeWrite (MV_Bool v) i x = M.basicUnsafeWrite v i (fromBool x)
@@ -354,6 +364,7 @@
   {-# INLINE basicUnsafeSlice #-}
   {-# INLINE basicOverlaps #-}
   {-# INLINE basicUnsafeNew #-}
+  {-# INLINE basicInitialize #-}
   {-# INLINE basicUnsafeReplicate #-}
   {-# INLINE basicUnsafeRead #-}
   {-# INLINE basicUnsafeWrite #-}
@@ -365,6 +376,7 @@
   basicUnsafeSlice i n (MV_Complex v) = MV_Complex $ M.basicUnsafeSlice i n v
   basicOverlaps (MV_Complex v1) (MV_Complex v2) = M.basicOverlaps v1 v2
   basicUnsafeNew n = MV_Complex `liftM` M.basicUnsafeNew n
+  basicInitialize (MV_Complex v) = M.basicInitialize v
   basicUnsafeReplicate n (x :+ y) = MV_Complex `liftM` M.basicUnsafeReplicate n (x,y)
   basicUnsafeRead (MV_Complex v) i = uncurry (:+) `liftM` M.basicUnsafeRead v i
   basicUnsafeWrite (MV_Complex v) i (x :+ y) = M.basicUnsafeWrite v i (x,y)
diff --git a/Data/Vector/Unboxed/Mutable.hs b/Data/Vector/Unboxed/Mutable.hs
--- a/Data/Vector/Unboxed/Mutable.hs
+++ b/Data/Vector/Unboxed/Mutable.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE CPP #-}
+
 -- |
 -- Module      : Data.Vector.Unboxed.Mutable
 -- Copyright   : (c) Roman Leshchinskiy 2009-2010
@@ -42,8 +44,8 @@
   unzip, unzip3, unzip4, unzip5, unzip6,
 
   -- * Accessing individual elements
-  read, write, swap,
-  unsafeRead, unsafeWrite, unsafeSwap,
+  read, write, modify, swap,
+  unsafeRead, unsafeWrite, unsafeModify, unsafeSwap,
 
   -- * Modifying vectors
 
@@ -60,6 +62,8 @@
                         take, drop, splitAt, init, tail,
                         zip, zip3, unzip, unzip3 )
 
+-- don't import an unused Data.Vector.Internal.Check
+#define NOT_VECTOR_MODULE
 #include "vector.h"
 
 -- Length information
@@ -132,7 +136,7 @@
 -- Overlapping
 -- -----------
 
--- Check whether two vectors overlap.
+-- | Check whether two vectors overlap.
 overlaps :: Unbox a => MVector s a -> MVector s a -> Bool
 {-# INLINE overlaps #-}
 overlaps = G.overlaps
@@ -173,7 +177,7 @@
 
 -- | Grow a vector by the given number of elements. The number must be
 -- positive.
-grow :: (PrimMonad m, Unbox a)  
+grow :: (PrimMonad m, Unbox a)
               => MVector (PrimState m) a -> Int -> m (MVector (PrimState m) a)
 {-# INLINE grow #-}
 grow = G.grow
@@ -189,7 +193,7 @@
 -- ------------------------
 
 -- | Reset all elements of the vector to some undefined value, clearing all
--- references to external objects. This is usually a noop for unboxed vectors. 
+-- references to external objects. This is usually a noop for unboxed vectors.
 clear :: (PrimMonad m, Unbox a) => MVector (PrimState m) a -> m ()
 {-# INLINE clear #-}
 clear = G.clear
@@ -207,6 +211,11 @@
 {-# INLINE write #-}
 write = G.write
 
+-- | Modify the element at the given position.
+modify :: (PrimMonad m, Unbox a) => MVector (PrimState m) a -> (a -> a) -> Int -> m ()
+{-# INLINE modify #-}
+modify = G.modify
+
 -- | Swap the elements at the given positions.
 swap :: (PrimMonad m, Unbox a) => MVector (PrimState m) a -> Int -> Int -> m ()
 {-# INLINE swap #-}
@@ -224,6 +233,11 @@
 {-# INLINE unsafeWrite #-}
 unsafeWrite = G.unsafeWrite
 
+-- | Modify the element at the given position. No bounds checks are performed.
+unsafeModify :: (PrimMonad m, Unbox a) => MVector (PrimState m) a -> (a -> a) -> Int -> m ()
+{-# INLINE unsafeModify #-}
+unsafeModify = G.unsafeModify
+
 -- | Swap the elements at the given positions. No bounds checks are performed.
 unsafeSwap
     :: (PrimMonad m, Unbox a) => MVector (PrimState m) a -> Int -> Int -> m ()
@@ -240,7 +254,7 @@
 
 -- | Copy a vector. The two vectors must have the same length and may not
 -- overlap.
-copy :: (PrimMonad m, Unbox a) 
+copy :: (PrimMonad m, Unbox a)
                  => MVector (PrimState m) a -> MVector (PrimState m) a -> m ()
 {-# INLINE copy #-}
 copy = G.copy
@@ -256,7 +270,7 @@
 
 -- | Move the contents of a vector. The two vectors must have the same
 -- length.
--- 
+--
 -- If the vectors do not overlap, then this is equivalent to 'copy'.
 -- Otherwise, the copying is performed as if the source vector were
 -- copied to a temporary vector and then the temporary vector was copied
@@ -268,7 +282,7 @@
 
 -- | Move the contents of a vector. The two vectors must have the same
 -- length, but this is not checked.
--- 
+--
 -- If the vectors do not overlap, then this is equivalent to 'unsafeCopy'.
 -- Otherwise, the copying is performed as if the source vector were
 -- copied to a temporary vector and then the temporary vector was copied
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,4 +1,6 @@
-# The vector package
+The `vector` package [![Build Status](https://travis-ci.org/haskell/vector.png?branch=master)](https://travis-ci.org/haskell/vector)
+====================
 
-An efficient implementation of Int-indexed arrays (both mutable and
-immutable), with a powerful loop optimisation framework.
+An efficient implementation of Int-indexed arrays (both mutable and immutable), with a powerful loop optimisation framework.
+
+See [`vector` on Hackage](http://hackage.haskell.org/package/vector) for more information.
diff --git a/benchmarks/vector-benchmarks.cabal b/benchmarks/vector-benchmarks.cabal
--- a/benchmarks/vector-benchmarks.cabal
+++ b/benchmarks/vector-benchmarks.cabal
@@ -1,5 +1,5 @@
 Name:           vector-benchmarks
-Version:        0.10.0.1
+Version:        0.10.9
 License:        BSD3
 License-File:   LICENSE
 Author:         Roman Leshchinskiy <rl@cse.unsw.edu.au>
@@ -14,7 +14,7 @@
   Build-Depends: base >= 2 && < 5, array,
                  criterion >= 0.5 && < 0.7,
                  mwc-random >= 0.5 && < 0.13,
-                 vector == 0.10.0.1
+                 vector == 0.10.9
 
   if impl(ghc<6.13)
     Ghc-Options: -finline-if-enough-args -fno-method-sharing
diff --git a/changelog b/changelog
--- a/changelog
+++ b/changelog
@@ -1,3 +1,13 @@
+Changes in version 0.11.0.0
+
+ * Define `Applicative` instances for `Data.Vector.Fusion.Util.{Box,Id}`
+ * Define non-bottom `fail` for `instance Monad Vector`
+ * New generalized stream fusion framework
+ * Various safety fixes
+   - Various overflows due to vector size have been eliminated
+   - Memory is initialized on creation of unboxed vectors
+ * Changes to SPEC usage to allow building under more conditions
+
 Changes in version 0.10.12.3
 
  * Allow building with `primtive-0.6`
diff --git a/include/vector.h b/include/vector.h
--- a/include/vector.h
+++ b/include/vector.h
@@ -1,8 +1,8 @@
-#define PHASE_STREAM [1]
-#define PHASE_INNER  [0]
+#define PHASE_FUSED [1]
+#define PHASE_INNER [0]
 
-#define INLINE_STREAM INLINE PHASE_STREAM
-#define INLINE_INNER  INLINE PHASE_INNER
+#define INLINE_FUSED INLINE PHASE_FUSED
+#define INLINE_INNER INLINE PHASE_INNER
 
 #ifndef NOT_VECTOR_MODULE
 import qualified Data.Vector.Internal.Check as Ck
@@ -16,4 +16,6 @@
 #define UNSAFE_CHECK(f) (CHECK(f) Ck.Unsafe)
 #define INTERNAL_CHECK(f) (CHECK(f) Ck.Internal)
 
+#define PHASE_STREAM  Please use "PHASE_FUSED" instead
+#define INLINE_STREAM Please use "INLINE_FUSED" instead
 
diff --git a/internal/GenUnboxTuple.hs b/internal/GenUnboxTuple.hs
--- a/internal/GenUnboxTuple.hs
+++ b/internal/GenUnboxTuple.hs
@@ -59,7 +59,7 @@
                   <+> sep (punctuate (text " ->") [text ty <+> v | v <- vars])
                   <+> text "->"
                   <+> text ty <+> tuple vars
-             ,text "{-# INLINE_STREAM"  <+> name <+> text "#-}"
+             ,text "{-# INLINE_FUSED"  <+> name <+> text "#-}"
              ,name <+> sep varss
                    <+> text "="
                    <+> con c
@@ -84,7 +84,7 @@
              2 $
              text "G.stream" <+> parens (name "zip" <+> sep varss)
              <+> char '='
-             <+> text "Stream." <> name "zipWith" <+> tuple (replicate n empty)
+             <+> text "Bundle." <> name "zipWith" <+> tuple (replicate n empty)
              <+> sep [parens $ text "G.stream" <+> vs | vs <- varss]
              $$ text "#-}"
      where
diff --git a/internal/unbox-tuple-instances b/internal/unbox-tuple-instances
--- a/internal/unbox-tuple-instances
+++ b/internal/unbox-tuple-instances
@@ -8,13 +8,13 @@
 instance (Unbox a, Unbox b) => Unbox (a, b)
 instance (Unbox a, Unbox b) => M.MVector MVector (a, b) where
   {-# INLINE basicLength  #-}
-  basicLength (MV_2 n_ as bs) = n_
+  basicLength (MV_2 n_ _ _) = n_
   {-# INLINE basicUnsafeSlice  #-}
-  basicUnsafeSlice i_ m_ (MV_2 n_ as bs)
+  basicUnsafeSlice i_ m_ (MV_2 _ as bs)
       = MV_2 m_ (M.basicUnsafeSlice i_ m_ as)
                 (M.basicUnsafeSlice i_ m_ bs)
   {-# INLINE basicOverlaps  #-}
-  basicOverlaps (MV_2 n_1 as1 bs1) (MV_2 n_2 as2 bs2)
+  basicOverlaps (MV_2 _ as1 bs1) (MV_2 _ as2 bs2)
       = M.basicOverlaps as1 as2
         || M.basicOverlaps bs1 bs2
   {-# INLINE basicUnsafeNew  #-}
@@ -23,6 +23,11 @@
           as <- M.basicUnsafeNew n_
           bs <- M.basicUnsafeNew n_
           return $ MV_2 n_ as bs
+  {-# INLINE basicInitialize  #-}
+  basicInitialize (MV_2 _ as bs)
+      = do
+          M.basicInitialize as
+          M.basicInitialize bs
   {-# INLINE basicUnsafeReplicate  #-}
   basicUnsafeReplicate n_ (a, b)
       = do
@@ -30,33 +35,33 @@
           bs <- M.basicUnsafeReplicate n_ b
           return $ MV_2 n_ as bs
   {-# INLINE basicUnsafeRead  #-}
-  basicUnsafeRead (MV_2 n_ as bs) i_
+  basicUnsafeRead (MV_2 _ as bs) i_
       = do
           a <- M.basicUnsafeRead as i_
           b <- M.basicUnsafeRead bs i_
           return (a, b)
   {-# INLINE basicUnsafeWrite  #-}
-  basicUnsafeWrite (MV_2 n_ as bs) i_ (a, b)
+  basicUnsafeWrite (MV_2 _ as bs) i_ (a, b)
       = do
           M.basicUnsafeWrite as i_ a
           M.basicUnsafeWrite bs i_ b
   {-# INLINE basicClear  #-}
-  basicClear (MV_2 n_ as bs)
+  basicClear (MV_2 _ as bs)
       = do
           M.basicClear as
           M.basicClear bs
   {-# INLINE basicSet  #-}
-  basicSet (MV_2 n_ as bs) (a, b)
+  basicSet (MV_2 _ as bs) (a, b)
       = do
           M.basicSet as a
           M.basicSet bs b
   {-# INLINE basicUnsafeCopy  #-}
-  basicUnsafeCopy (MV_2 n_1 as1 bs1) (MV_2 n_2 as2 bs2)
+  basicUnsafeCopy (MV_2 _ as1 bs1) (MV_2 _ as2 bs2)
       = do
           M.basicUnsafeCopy as1 as2
           M.basicUnsafeCopy bs1 bs2
   {-# INLINE basicUnsafeMove  #-}
-  basicUnsafeMove (MV_2 n_1 as1 bs1) (MV_2 n_2 as2 bs2)
+  basicUnsafeMove (MV_2 _ as1 bs1) (MV_2 _ as2 bs2)
       = do
           M.basicUnsafeMove as1 as2
           M.basicUnsafeMove bs1 bs2
@@ -80,19 +85,19 @@
           bs' <- G.basicUnsafeThaw bs
           return $ MV_2 n_ as' bs'
   {-# INLINE basicLength  #-}
-  basicLength (V_2 n_ as bs) = n_
+  basicLength (V_2 n_ _ _) = n_
   {-# INLINE basicUnsafeSlice  #-}
-  basicUnsafeSlice i_ m_ (V_2 n_ as bs)
+  basicUnsafeSlice i_ m_ (V_2 _ as bs)
       = V_2 m_ (G.basicUnsafeSlice i_ m_ as)
                (G.basicUnsafeSlice i_ m_ bs)
   {-# INLINE basicUnsafeIndexM  #-}
-  basicUnsafeIndexM (V_2 n_ as bs) i_
+  basicUnsafeIndexM (V_2 _ as bs) i_
       = do
           a <- G.basicUnsafeIndexM as i_
           b <- G.basicUnsafeIndexM bs i_
           return (a, b)
   {-# INLINE basicUnsafeCopy  #-}
-  basicUnsafeCopy (MV_2 n_1 as1 bs1) (V_2 n_2 as2 bs2)
+  basicUnsafeCopy (MV_2 _ as1 bs1) (V_2 _ as2 bs2)
       = do
           G.basicUnsafeCopy as1 as2
           G.basicUnsafeCopy bs1 bs2
@@ -105,30 +110,30 @@
 -- | /O(1)/ Zip 2 vectors
 zip :: (Unbox a, Unbox b) => MVector s a ->
                              MVector s b -> MVector s (a, b)
-{-# INLINE_STREAM zip #-}
+{-# INLINE_FUSED zip #-}
 zip as bs = MV_2 len (unsafeSlice 0 len as) (unsafeSlice 0 len bs)
   where len = length as `delayed_min` length bs
 -- | /O(1)/ Unzip 2 vectors
 unzip :: (Unbox a, Unbox b) => MVector s (a, b) -> (MVector s a,
                                                     MVector s b)
 {-# INLINE unzip #-}
-unzip (MV_2 n_ as bs) = (as, bs)
+unzip (MV_2 _ as bs) = (as, bs)
 #endif
 #ifdef DEFINE_IMMUTABLE
 -- | /O(1)/ Zip 2 vectors
 zip :: (Unbox a, Unbox b) => Vector a -> Vector b -> Vector (a, b)
-{-# INLINE_STREAM zip #-}
+{-# INLINE_FUSED zip #-}
 zip as bs = V_2 len (unsafeSlice 0 len as) (unsafeSlice 0 len bs)
   where len = length as `delayed_min` length bs
 {-# RULES "stream/zip [Vector.Unboxed]" forall as bs .
-  G.stream (zip as bs) = Stream.zipWith (,) (G.stream as)
-                                            (G.stream bs)
-  #-}
+  G.stream (zip as bs) = Bundle.zipWith (,) (G.stream as)
+                                            (G.stream bs)   #-}
+
 -- | /O(1)/ Unzip 2 vectors
 unzip :: (Unbox a, Unbox b) => Vector (a, b) -> (Vector a,
                                                  Vector b)
 {-# INLINE unzip #-}
-unzip (V_2 n_ as bs) = (as, bs)
+unzip (V_2 _ as bs) = (as, bs)
 #endif
 #ifdef DEFINE_INSTANCES
 data instance MVector s (a, b, c)
@@ -144,14 +149,14 @@
           Unbox b,
           Unbox c) => M.MVector MVector (a, b, c) where
   {-# INLINE basicLength  #-}
-  basicLength (MV_3 n_ as bs cs) = n_
+  basicLength (MV_3 n_ _ _ _) = n_
   {-# INLINE basicUnsafeSlice  #-}
-  basicUnsafeSlice i_ m_ (MV_3 n_ as bs cs)
+  basicUnsafeSlice i_ m_ (MV_3 _ as bs cs)
       = MV_3 m_ (M.basicUnsafeSlice i_ m_ as)
                 (M.basicUnsafeSlice i_ m_ bs)
                 (M.basicUnsafeSlice i_ m_ cs)
   {-# INLINE basicOverlaps  #-}
-  basicOverlaps (MV_3 n_1 as1 bs1 cs1) (MV_3 n_2 as2 bs2 cs2)
+  basicOverlaps (MV_3 _ as1 bs1 cs1) (MV_3 _ as2 bs2 cs2)
       = M.basicOverlaps as1 as2
         || M.basicOverlaps bs1 bs2
         || M.basicOverlaps cs1 cs2
@@ -162,6 +167,12 @@
           bs <- M.basicUnsafeNew n_
           cs <- M.basicUnsafeNew n_
           return $ MV_3 n_ as bs cs
+  {-# INLINE basicInitialize #-}
+  basicInitialize (MV_3 _ as bs cs)
+      = do
+          M.basicInitialize as
+          M.basicInitialize bs
+          M.basicInitialize cs
   {-# INLINE basicUnsafeReplicate  #-}
   basicUnsafeReplicate n_ (a, b, c)
       = do
@@ -170,38 +181,38 @@
           cs <- M.basicUnsafeReplicate n_ c
           return $ MV_3 n_ as bs cs
   {-# INLINE basicUnsafeRead  #-}
-  basicUnsafeRead (MV_3 n_ as bs cs) i_
+  basicUnsafeRead (MV_3 _ as bs cs) i_
       = do
           a <- M.basicUnsafeRead as i_
           b <- M.basicUnsafeRead bs i_
           c <- M.basicUnsafeRead cs i_
           return (a, b, c)
   {-# INLINE basicUnsafeWrite  #-}
-  basicUnsafeWrite (MV_3 n_ as bs cs) i_ (a, b, c)
+  basicUnsafeWrite (MV_3 _ as bs cs) i_ (a, b, c)
       = do
           M.basicUnsafeWrite as i_ a
           M.basicUnsafeWrite bs i_ b
           M.basicUnsafeWrite cs i_ c
   {-# INLINE basicClear  #-}
-  basicClear (MV_3 n_ as bs cs)
+  basicClear (MV_3 _ as bs cs)
       = do
           M.basicClear as
           M.basicClear bs
           M.basicClear cs
   {-# INLINE basicSet  #-}
-  basicSet (MV_3 n_ as bs cs) (a, b, c)
+  basicSet (MV_3 _ as bs cs) (a, b, c)
       = do
           M.basicSet as a
           M.basicSet bs b
           M.basicSet cs c
   {-# INLINE basicUnsafeCopy  #-}
-  basicUnsafeCopy (MV_3 n_1 as1 bs1 cs1) (MV_3 n_2 as2 bs2 cs2)
+  basicUnsafeCopy (MV_3 _ as1 bs1 cs1) (MV_3 _ as2 bs2 cs2)
       = do
           M.basicUnsafeCopy as1 as2
           M.basicUnsafeCopy bs1 bs2
           M.basicUnsafeCopy cs1 cs2
   {-# INLINE basicUnsafeMove  #-}
-  basicUnsafeMove (MV_3 n_1 as1 bs1 cs1) (MV_3 n_2 as2 bs2 cs2)
+  basicUnsafeMove (MV_3 _ as1 bs1 cs1) (MV_3 _ as2 bs2 cs2)
       = do
           M.basicUnsafeMove as1 as2
           M.basicUnsafeMove bs1 bs2
@@ -231,21 +242,21 @@
           cs' <- G.basicUnsafeThaw cs
           return $ MV_3 n_ as' bs' cs'
   {-# INLINE basicLength  #-}
-  basicLength (V_3 n_ as bs cs) = n_
+  basicLength (V_3 n_ _ _ _) = n_
   {-# INLINE basicUnsafeSlice  #-}
-  basicUnsafeSlice i_ m_ (V_3 n_ as bs cs)
+  basicUnsafeSlice i_ m_ (V_3 _ as bs cs)
       = V_3 m_ (G.basicUnsafeSlice i_ m_ as)
                (G.basicUnsafeSlice i_ m_ bs)
                (G.basicUnsafeSlice i_ m_ cs)
   {-# INLINE basicUnsafeIndexM  #-}
-  basicUnsafeIndexM (V_3 n_ as bs cs) i_
+  basicUnsafeIndexM (V_3 _ as bs cs) i_
       = do
           a <- G.basicUnsafeIndexM as i_
           b <- G.basicUnsafeIndexM bs i_
           c <- G.basicUnsafeIndexM cs i_
           return (a, b, c)
   {-# INLINE basicUnsafeCopy  #-}
-  basicUnsafeCopy (MV_3 n_1 as1 bs1 cs1) (V_3 n_2 as2 bs2 cs2)
+  basicUnsafeCopy (MV_3 _ as1 bs1 cs1) (V_3 _ as2 bs2 cs2)
       = do
           G.basicUnsafeCopy as1 as2
           G.basicUnsafeCopy bs1 bs2
@@ -261,7 +272,7 @@
 zip3 :: (Unbox a, Unbox b, Unbox c) => MVector s a ->
                                        MVector s b ->
                                        MVector s c -> MVector s (a, b, c)
-{-# INLINE_STREAM zip3 #-}
+{-# INLINE_FUSED zip3 #-}
 zip3 as bs cs = MV_3 len (unsafeSlice 0 len as)
                          (unsafeSlice 0 len bs)
                          (unsafeSlice 0 len cs)
@@ -274,30 +285,30 @@
                                                MVector s b,
                                                MVector s c)
 {-# INLINE unzip3 #-}
-unzip3 (MV_3 n_ as bs cs) = (as, bs, cs)
+unzip3 (MV_3 _ as bs cs) = (as, bs, cs)
 #endif
 #ifdef DEFINE_IMMUTABLE
 -- | /O(1)/ Zip 3 vectors
 zip3 :: (Unbox a, Unbox b, Unbox c) => Vector a ->
                                        Vector b ->
                                        Vector c -> Vector (a, b, c)
-{-# INLINE_STREAM zip3 #-}
+{-# INLINE_FUSED zip3 #-}
 zip3 as bs cs = V_3 len (unsafeSlice 0 len as)
                         (unsafeSlice 0 len bs)
                         (unsafeSlice 0 len cs)
   where
     len = length as `delayed_min` length bs `delayed_min` length cs
 {-# RULES "stream/zip3 [Vector.Unboxed]" forall as bs cs .
-  G.stream (zip3 as bs cs) = Stream.zipWith3 (, ,) (G.stream as)
+  G.stream (zip3 as bs cs) = Bundle.zipWith3 (, ,) (G.stream as)
                                                    (G.stream bs)
-                                                   (G.stream cs)
-  #-}
+                                                   (G.stream cs)   #-}
+
 -- | /O(1)/ Unzip 3 vectors
 unzip3 :: (Unbox a,
            Unbox b,
            Unbox c) => Vector (a, b, c) -> (Vector a, Vector b, Vector c)
 {-# INLINE unzip3 #-}
-unzip3 (V_3 n_ as bs cs) = (as, bs, cs)
+unzip3 (V_3 _ as bs cs) = (as, bs, cs)
 #endif
 #ifdef DEFINE_INSTANCES
 data instance MVector s (a, b, c, d)
@@ -316,15 +327,15 @@
           Unbox c,
           Unbox d) => M.MVector MVector (a, b, c, d) where
   {-# INLINE basicLength  #-}
-  basicLength (MV_4 n_ as bs cs ds) = n_
+  basicLength (MV_4 n_ _ _ _ _) = n_
   {-# INLINE basicUnsafeSlice  #-}
-  basicUnsafeSlice i_ m_ (MV_4 n_ as bs cs ds)
+  basicUnsafeSlice i_ m_ (MV_4 _ as bs cs ds)
       = MV_4 m_ (M.basicUnsafeSlice i_ m_ as)
                 (M.basicUnsafeSlice i_ m_ bs)
                 (M.basicUnsafeSlice i_ m_ cs)
                 (M.basicUnsafeSlice i_ m_ ds)
   {-# INLINE basicOverlaps  #-}
-  basicOverlaps (MV_4 n_1 as1 bs1 cs1 ds1) (MV_4 n_2 as2 bs2 cs2 ds2)
+  basicOverlaps (MV_4 _ as1 bs1 cs1 ds1) (MV_4 _ as2 bs2 cs2 ds2)
       = M.basicOverlaps as1 as2
         || M.basicOverlaps bs1 bs2
         || M.basicOverlaps cs1 cs2
@@ -337,6 +348,13 @@
           cs <- M.basicUnsafeNew n_
           ds <- M.basicUnsafeNew n_
           return $ MV_4 n_ as bs cs ds
+  {-# INLINE basicInitialize #-}
+  basicInitialize (MV_4 _ as bs cs ds)
+      = do
+          M.basicInitialize as
+          M.basicInitialize bs
+          M.basicInitialize cs
+          M.basicInitialize ds
   {-# INLINE basicUnsafeReplicate  #-}
   basicUnsafeReplicate n_ (a, b, c, d)
       = do
@@ -346,7 +364,7 @@
           ds <- M.basicUnsafeReplicate n_ d
           return $ MV_4 n_ as bs cs ds
   {-# INLINE basicUnsafeRead  #-}
-  basicUnsafeRead (MV_4 n_ as bs cs ds) i_
+  basicUnsafeRead (MV_4 _ as bs cs ds) i_
       = do
           a <- M.basicUnsafeRead as i_
           b <- M.basicUnsafeRead bs i_
@@ -354,41 +372,41 @@
           d <- M.basicUnsafeRead ds i_
           return (a, b, c, d)
   {-# INLINE basicUnsafeWrite  #-}
-  basicUnsafeWrite (MV_4 n_ as bs cs ds) i_ (a, b, c, d)
+  basicUnsafeWrite (MV_4 _ as bs cs ds) i_ (a, b, c, d)
       = do
           M.basicUnsafeWrite as i_ a
           M.basicUnsafeWrite bs i_ b
           M.basicUnsafeWrite cs i_ c
           M.basicUnsafeWrite ds i_ d
   {-# INLINE basicClear  #-}
-  basicClear (MV_4 n_ as bs cs ds)
+  basicClear (MV_4 _ as bs cs ds)
       = do
           M.basicClear as
           M.basicClear bs
           M.basicClear cs
           M.basicClear ds
   {-# INLINE basicSet  #-}
-  basicSet (MV_4 n_ as bs cs ds) (a, b, c, d)
+  basicSet (MV_4 _ as bs cs ds) (a, b, c, d)
       = do
           M.basicSet as a
           M.basicSet bs b
           M.basicSet cs c
           M.basicSet ds d
   {-# INLINE basicUnsafeCopy  #-}
-  basicUnsafeCopy (MV_4 n_1 as1 bs1 cs1 ds1) (MV_4 n_2 as2
-                                                       bs2
-                                                       cs2
-                                                       ds2)
+  basicUnsafeCopy (MV_4 _ as1 bs1 cs1 ds1) (MV_4 _ as2
+                                                   bs2
+                                                   cs2
+                                                   ds2)
       = do
           M.basicUnsafeCopy as1 as2
           M.basicUnsafeCopy bs1 bs2
           M.basicUnsafeCopy cs1 cs2
           M.basicUnsafeCopy ds1 ds2
   {-# INLINE basicUnsafeMove  #-}
-  basicUnsafeMove (MV_4 n_1 as1 bs1 cs1 ds1) (MV_4 n_2 as2
-                                                       bs2
-                                                       cs2
-                                                       ds2)
+  basicUnsafeMove (MV_4 _ as1 bs1 cs1 ds1) (MV_4 _ as2
+                                                   bs2
+                                                   cs2
+                                                   ds2)
       = do
           M.basicUnsafeMove as1 as2
           M.basicUnsafeMove bs1 bs2
@@ -423,15 +441,15 @@
           ds' <- G.basicUnsafeThaw ds
           return $ MV_4 n_ as' bs' cs' ds'
   {-# INLINE basicLength  #-}
-  basicLength (V_4 n_ as bs cs ds) = n_
+  basicLength (V_4 n_ _ _ _ _) = n_
   {-# INLINE basicUnsafeSlice  #-}
-  basicUnsafeSlice i_ m_ (V_4 n_ as bs cs ds)
+  basicUnsafeSlice i_ m_ (V_4 _ as bs cs ds)
       = V_4 m_ (G.basicUnsafeSlice i_ m_ as)
                (G.basicUnsafeSlice i_ m_ bs)
                (G.basicUnsafeSlice i_ m_ cs)
                (G.basicUnsafeSlice i_ m_ ds)
   {-# INLINE basicUnsafeIndexM  #-}
-  basicUnsafeIndexM (V_4 n_ as bs cs ds) i_
+  basicUnsafeIndexM (V_4 _ as bs cs ds) i_
       = do
           a <- G.basicUnsafeIndexM as i_
           b <- G.basicUnsafeIndexM bs i_
@@ -439,10 +457,10 @@
           d <- G.basicUnsafeIndexM ds i_
           return (a, b, c, d)
   {-# INLINE basicUnsafeCopy  #-}
-  basicUnsafeCopy (MV_4 n_1 as1 bs1 cs1 ds1) (V_4 n_2 as2
-                                                      bs2
-                                                      cs2
-                                                      ds2)
+  basicUnsafeCopy (MV_4 _ as1 bs1 cs1 ds1) (V_4 _ as2
+                                                  bs2
+                                                  cs2
+                                                  ds2)
       = do
           G.basicUnsafeCopy as1 as2
           G.basicUnsafeCopy bs1 bs2
@@ -461,7 +479,7 @@
                                                 MVector s b ->
                                                 MVector s c ->
                                                 MVector s d -> MVector s (a, b, c, d)
-{-# INLINE_STREAM zip4 #-}
+{-# INLINE_FUSED zip4 #-}
 zip4 as bs cs ds = MV_4 len (unsafeSlice 0 len as)
                             (unsafeSlice 0 len bs)
                             (unsafeSlice 0 len cs)
@@ -480,7 +498,7 @@
                                                   MVector s c,
                                                   MVector s d)
 {-# INLINE unzip4 #-}
-unzip4 (MV_4 n_ as bs cs ds) = (as, bs, cs, ds)
+unzip4 (MV_4 _ as bs cs ds) = (as, bs, cs, ds)
 #endif
 #ifdef DEFINE_IMMUTABLE
 -- | /O(1)/ Zip 4 vectors
@@ -488,7 +506,7 @@
                                                 Vector b ->
                                                 Vector c ->
                                                 Vector d -> Vector (a, b, c, d)
-{-# INLINE_STREAM zip4 #-}
+{-# INLINE_FUSED zip4 #-}
 zip4 as bs cs ds = V_4 len (unsafeSlice 0 len as)
                            (unsafeSlice 0 len bs)
                            (unsafeSlice 0 len cs)
@@ -499,11 +517,11 @@
           length cs `delayed_min`
           length ds
 {-# RULES "stream/zip4 [Vector.Unboxed]" forall as bs cs ds .
-  G.stream (zip4 as bs cs ds) = Stream.zipWith4 (, , ,) (G.stream as)
+  G.stream (zip4 as bs cs ds) = Bundle.zipWith4 (, , ,) (G.stream as)
                                                         (G.stream bs)
                                                         (G.stream cs)
-                                                        (G.stream ds)
-  #-}
+                                                        (G.stream ds)   #-}
+
 -- | /O(1)/ Unzip 4 vectors
 unzip4 :: (Unbox a,
            Unbox b,
@@ -513,7 +531,7 @@
                                                Vector c,
                                                Vector d)
 {-# INLINE unzip4 #-}
-unzip4 (V_4 n_ as bs cs ds) = (as, bs, cs, ds)
+unzip4 (V_4 _ as bs cs ds) = (as, bs, cs, ds)
 #endif
 #ifdef DEFINE_INSTANCES
 data instance MVector s (a, b, c, d, e)
@@ -539,20 +557,20 @@
           Unbox d,
           Unbox e) => M.MVector MVector (a, b, c, d, e) where
   {-# INLINE basicLength  #-}
-  basicLength (MV_5 n_ as bs cs ds es) = n_
+  basicLength (MV_5 n_ _ _ _ _ _) = n_
   {-# INLINE basicUnsafeSlice  #-}
-  basicUnsafeSlice i_ m_ (MV_5 n_ as bs cs ds es)
+  basicUnsafeSlice i_ m_ (MV_5 _ as bs cs ds es)
       = MV_5 m_ (M.basicUnsafeSlice i_ m_ as)
                 (M.basicUnsafeSlice i_ m_ bs)
                 (M.basicUnsafeSlice i_ m_ cs)
                 (M.basicUnsafeSlice i_ m_ ds)
                 (M.basicUnsafeSlice i_ m_ es)
   {-# INLINE basicOverlaps  #-}
-  basicOverlaps (MV_5 n_1 as1 bs1 cs1 ds1 es1) (MV_5 n_2 as2
-                                                         bs2
-                                                         cs2
-                                                         ds2
-                                                         es2)
+  basicOverlaps (MV_5 _ as1 bs1 cs1 ds1 es1) (MV_5 _ as2
+                                                     bs2
+                                                     cs2
+                                                     ds2
+                                                     es2)
       = M.basicOverlaps as1 as2
         || M.basicOverlaps bs1 bs2
         || M.basicOverlaps cs1 cs2
@@ -567,6 +585,14 @@
           ds <- M.basicUnsafeNew n_
           es <- M.basicUnsafeNew n_
           return $ MV_5 n_ as bs cs ds es
+  {-# INLINE basicInitialize #-}
+  basicInitialize (MV_5 _ as bs cs ds es)
+      = do
+          M.basicInitialize as
+          M.basicInitialize bs
+          M.basicInitialize cs
+          M.basicInitialize ds
+          M.basicInitialize es
   {-# INLINE basicUnsafeReplicate  #-}
   basicUnsafeReplicate n_ (a, b, c, d, e)
       = do
@@ -577,7 +603,7 @@
           es <- M.basicUnsafeReplicate n_ e
           return $ MV_5 n_ as bs cs ds es
   {-# INLINE basicUnsafeRead  #-}
-  basicUnsafeRead (MV_5 n_ as bs cs ds es) i_
+  basicUnsafeRead (MV_5 _ as bs cs ds es) i_
       = do
           a <- M.basicUnsafeRead as i_
           b <- M.basicUnsafeRead bs i_
@@ -586,7 +612,7 @@
           e <- M.basicUnsafeRead es i_
           return (a, b, c, d, e)
   {-# INLINE basicUnsafeWrite  #-}
-  basicUnsafeWrite (MV_5 n_ as bs cs ds es) i_ (a, b, c, d, e)
+  basicUnsafeWrite (MV_5 _ as bs cs ds es) i_ (a, b, c, d, e)
       = do
           M.basicUnsafeWrite as i_ a
           M.basicUnsafeWrite bs i_ b
@@ -594,7 +620,7 @@
           M.basicUnsafeWrite ds i_ d
           M.basicUnsafeWrite es i_ e
   {-# INLINE basicClear  #-}
-  basicClear (MV_5 n_ as bs cs ds es)
+  basicClear (MV_5 _ as bs cs ds es)
       = do
           M.basicClear as
           M.basicClear bs
@@ -602,7 +628,7 @@
           M.basicClear ds
           M.basicClear es
   {-# INLINE basicSet  #-}
-  basicSet (MV_5 n_ as bs cs ds es) (a, b, c, d, e)
+  basicSet (MV_5 _ as bs cs ds es) (a, b, c, d, e)
       = do
           M.basicSet as a
           M.basicSet bs b
@@ -610,11 +636,11 @@
           M.basicSet ds d
           M.basicSet es e
   {-# INLINE basicUnsafeCopy  #-}
-  basicUnsafeCopy (MV_5 n_1 as1 bs1 cs1 ds1 es1) (MV_5 n_2 as2
-                                                           bs2
-                                                           cs2
-                                                           ds2
-                                                           es2)
+  basicUnsafeCopy (MV_5 _ as1 bs1 cs1 ds1 es1) (MV_5 _ as2
+                                                       bs2
+                                                       cs2
+                                                       ds2
+                                                       es2)
       = do
           M.basicUnsafeCopy as1 as2
           M.basicUnsafeCopy bs1 bs2
@@ -622,11 +648,11 @@
           M.basicUnsafeCopy ds1 ds2
           M.basicUnsafeCopy es1 es2
   {-# INLINE basicUnsafeMove  #-}
-  basicUnsafeMove (MV_5 n_1 as1 bs1 cs1 ds1 es1) (MV_5 n_2 as2
-                                                           bs2
-                                                           cs2
-                                                           ds2
-                                                           es2)
+  basicUnsafeMove (MV_5 _ as1 bs1 cs1 ds1 es1) (MV_5 _ as2
+                                                       bs2
+                                                       cs2
+                                                       ds2
+                                                       es2)
       = do
           M.basicUnsafeMove as1 as2
           M.basicUnsafeMove bs1 bs2
@@ -666,16 +692,16 @@
           es' <- G.basicUnsafeThaw es
           return $ MV_5 n_ as' bs' cs' ds' es'
   {-# INLINE basicLength  #-}
-  basicLength (V_5 n_ as bs cs ds es) = n_
+  basicLength (V_5 n_ _ _ _ _ _) = n_
   {-# INLINE basicUnsafeSlice  #-}
-  basicUnsafeSlice i_ m_ (V_5 n_ as bs cs ds es)
+  basicUnsafeSlice i_ m_ (V_5 _ as bs cs ds es)
       = V_5 m_ (G.basicUnsafeSlice i_ m_ as)
                (G.basicUnsafeSlice i_ m_ bs)
                (G.basicUnsafeSlice i_ m_ cs)
                (G.basicUnsafeSlice i_ m_ ds)
                (G.basicUnsafeSlice i_ m_ es)
   {-# INLINE basicUnsafeIndexM  #-}
-  basicUnsafeIndexM (V_5 n_ as bs cs ds es) i_
+  basicUnsafeIndexM (V_5 _ as bs cs ds es) i_
       = do
           a <- G.basicUnsafeIndexM as i_
           b <- G.basicUnsafeIndexM bs i_
@@ -684,11 +710,11 @@
           e <- G.basicUnsafeIndexM es i_
           return (a, b, c, d, e)
   {-# INLINE basicUnsafeCopy  #-}
-  basicUnsafeCopy (MV_5 n_1 as1 bs1 cs1 ds1 es1) (V_5 n_2 as2
-                                                          bs2
-                                                          cs2
-                                                          ds2
-                                                          es2)
+  basicUnsafeCopy (MV_5 _ as1 bs1 cs1 ds1 es1) (V_5 _ as2
+                                                      bs2
+                                                      cs2
+                                                      ds2
+                                                      es2)
       = do
           G.basicUnsafeCopy as1 as2
           G.basicUnsafeCopy bs1 bs2
@@ -714,7 +740,7 @@
                      MVector s c ->
                      MVector s d ->
                      MVector s e -> MVector s (a, b, c, d, e)
-{-# INLINE_STREAM zip5 #-}
+{-# INLINE_FUSED zip5 #-}
 zip5 as bs cs ds es = MV_5 len (unsafeSlice 0 len as)
                                (unsafeSlice 0 len bs)
                                (unsafeSlice 0 len cs)
@@ -737,7 +763,7 @@
                                                      MVector s d,
                                                      MVector s e)
 {-# INLINE unzip5 #-}
-unzip5 (MV_5 n_ as bs cs ds es) = (as, bs, cs, ds, es)
+unzip5 (MV_5 _ as bs cs ds es) = (as, bs, cs, ds, es)
 #endif
 #ifdef DEFINE_IMMUTABLE
 -- | /O(1)/ Zip 5 vectors
@@ -750,7 +776,7 @@
                      Vector c ->
                      Vector d ->
                      Vector e -> Vector (a, b, c, d, e)
-{-# INLINE_STREAM zip5 #-}
+{-# INLINE_FUSED zip5 #-}
 zip5 as bs cs ds es = V_5 len (unsafeSlice 0 len as)
                               (unsafeSlice 0 len bs)
                               (unsafeSlice 0 len cs)
@@ -767,12 +793,12 @@
                  bs
                  cs
                  ds
-                 es) = Stream.zipWith5 (, , , ,) (G.stream as)
+                 es) = Bundle.zipWith5 (, , , ,) (G.stream as)
                                                  (G.stream bs)
                                                  (G.stream cs)
                                                  (G.stream ds)
-                                                 (G.stream es)
-  #-}
+                                                 (G.stream es)   #-}
+
 -- | /O(1)/ Unzip 5 vectors
 unzip5 :: (Unbox a,
            Unbox b,
@@ -784,7 +810,7 @@
                                                   Vector d,
                                                   Vector e)
 {-# INLINE unzip5 #-}
-unzip5 (V_5 n_ as bs cs ds es) = (as, bs, cs, ds, es)
+unzip5 (V_5 _ as bs cs ds es) = (as, bs, cs, ds, es)
 #endif
 #ifdef DEFINE_INSTANCES
 data instance MVector s (a, b, c, d, e, f)
@@ -814,9 +840,9 @@
           Unbox e,
           Unbox f) => M.MVector MVector (a, b, c, d, e, f) where
   {-# INLINE basicLength  #-}
-  basicLength (MV_6 n_ as bs cs ds es fs) = n_
+  basicLength (MV_6 n_ _ _ _ _ _ _) = n_
   {-# INLINE basicUnsafeSlice  #-}
-  basicUnsafeSlice i_ m_ (MV_6 n_ as bs cs ds es fs)
+  basicUnsafeSlice i_ m_ (MV_6 _ as bs cs ds es fs)
       = MV_6 m_ (M.basicUnsafeSlice i_ m_ as)
                 (M.basicUnsafeSlice i_ m_ bs)
                 (M.basicUnsafeSlice i_ m_ cs)
@@ -824,12 +850,12 @@
                 (M.basicUnsafeSlice i_ m_ es)
                 (M.basicUnsafeSlice i_ m_ fs)
   {-# INLINE basicOverlaps  #-}
-  basicOverlaps (MV_6 n_1 as1 bs1 cs1 ds1 es1 fs1) (MV_6 n_2 as2
-                                                             bs2
-                                                             cs2
-                                                             ds2
-                                                             es2
-                                                             fs2)
+  basicOverlaps (MV_6 _ as1 bs1 cs1 ds1 es1 fs1) (MV_6 _ as2
+                                                         bs2
+                                                         cs2
+                                                         ds2
+                                                         es2
+                                                         fs2)
       = M.basicOverlaps as1 as2
         || M.basicOverlaps bs1 bs2
         || M.basicOverlaps cs1 cs2
@@ -846,6 +872,15 @@
           es <- M.basicUnsafeNew n_
           fs <- M.basicUnsafeNew n_
           return $ MV_6 n_ as bs cs ds es fs
+  {-# INLINE basicInitialize #-}
+  basicInitialize (MV_6 _ as bs cs ds es fs)
+      = do
+          M.basicInitialize as
+          M.basicInitialize bs
+          M.basicInitialize cs
+          M.basicInitialize ds
+          M.basicInitialize es
+          M.basicInitialize fs
   {-# INLINE basicUnsafeReplicate  #-}
   basicUnsafeReplicate n_ (a, b, c, d, e, f)
       = do
@@ -857,7 +892,7 @@
           fs <- M.basicUnsafeReplicate n_ f
           return $ MV_6 n_ as bs cs ds es fs
   {-# INLINE basicUnsafeRead  #-}
-  basicUnsafeRead (MV_6 n_ as bs cs ds es fs) i_
+  basicUnsafeRead (MV_6 _ as bs cs ds es fs) i_
       = do
           a <- M.basicUnsafeRead as i_
           b <- M.basicUnsafeRead bs i_
@@ -867,7 +902,7 @@
           f <- M.basicUnsafeRead fs i_
           return (a, b, c, d, e, f)
   {-# INLINE basicUnsafeWrite  #-}
-  basicUnsafeWrite (MV_6 n_ as bs cs ds es fs) i_ (a, b, c, d, e, f)
+  basicUnsafeWrite (MV_6 _ as bs cs ds es fs) i_ (a, b, c, d, e, f)
       = do
           M.basicUnsafeWrite as i_ a
           M.basicUnsafeWrite bs i_ b
@@ -876,7 +911,7 @@
           M.basicUnsafeWrite es i_ e
           M.basicUnsafeWrite fs i_ f
   {-# INLINE basicClear  #-}
-  basicClear (MV_6 n_ as bs cs ds es fs)
+  basicClear (MV_6 _ as bs cs ds es fs)
       = do
           M.basicClear as
           M.basicClear bs
@@ -885,7 +920,7 @@
           M.basicClear es
           M.basicClear fs
   {-# INLINE basicSet  #-}
-  basicSet (MV_6 n_ as bs cs ds es fs) (a, b, c, d, e, f)
+  basicSet (MV_6 _ as bs cs ds es fs) (a, b, c, d, e, f)
       = do
           M.basicSet as a
           M.basicSet bs b
@@ -894,12 +929,12 @@
           M.basicSet es e
           M.basicSet fs f
   {-# INLINE basicUnsafeCopy  #-}
-  basicUnsafeCopy (MV_6 n_1 as1 bs1 cs1 ds1 es1 fs1) (MV_6 n_2 as2
-                                                               bs2
-                                                               cs2
-                                                               ds2
-                                                               es2
-                                                               fs2)
+  basicUnsafeCopy (MV_6 _ as1 bs1 cs1 ds1 es1 fs1) (MV_6 _ as2
+                                                           bs2
+                                                           cs2
+                                                           ds2
+                                                           es2
+                                                           fs2)
       = do
           M.basicUnsafeCopy as1 as2
           M.basicUnsafeCopy bs1 bs2
@@ -908,12 +943,12 @@
           M.basicUnsafeCopy es1 es2
           M.basicUnsafeCopy fs1 fs2
   {-# INLINE basicUnsafeMove  #-}
-  basicUnsafeMove (MV_6 n_1 as1 bs1 cs1 ds1 es1 fs1) (MV_6 n_2 as2
-                                                               bs2
-                                                               cs2
-                                                               ds2
-                                                               es2
-                                                               fs2)
+  basicUnsafeMove (MV_6 _ as1 bs1 cs1 ds1 es1 fs1) (MV_6 _ as2
+                                                           bs2
+                                                           cs2
+                                                           ds2
+                                                           es2
+                                                           fs2)
       = do
           M.basicUnsafeMove as1 as2
           M.basicUnsafeMove bs1 bs2
@@ -958,9 +993,9 @@
           fs' <- G.basicUnsafeThaw fs
           return $ MV_6 n_ as' bs' cs' ds' es' fs'
   {-# INLINE basicLength  #-}
-  basicLength (V_6 n_ as bs cs ds es fs) = n_
+  basicLength (V_6 n_ _ _ _ _ _ _) = n_
   {-# INLINE basicUnsafeSlice  #-}
-  basicUnsafeSlice i_ m_ (V_6 n_ as bs cs ds es fs)
+  basicUnsafeSlice i_ m_ (V_6 _ as bs cs ds es fs)
       = V_6 m_ (G.basicUnsafeSlice i_ m_ as)
                (G.basicUnsafeSlice i_ m_ bs)
                (G.basicUnsafeSlice i_ m_ cs)
@@ -968,7 +1003,7 @@
                (G.basicUnsafeSlice i_ m_ es)
                (G.basicUnsafeSlice i_ m_ fs)
   {-# INLINE basicUnsafeIndexM  #-}
-  basicUnsafeIndexM (V_6 n_ as bs cs ds es fs) i_
+  basicUnsafeIndexM (V_6 _ as bs cs ds es fs) i_
       = do
           a <- G.basicUnsafeIndexM as i_
           b <- G.basicUnsafeIndexM bs i_
@@ -978,12 +1013,12 @@
           f <- G.basicUnsafeIndexM fs i_
           return (a, b, c, d, e, f)
   {-# INLINE basicUnsafeCopy  #-}
-  basicUnsafeCopy (MV_6 n_1 as1 bs1 cs1 ds1 es1 fs1) (V_6 n_2 as2
-                                                              bs2
-                                                              cs2
-                                                              ds2
-                                                              es2
-                                                              fs2)
+  basicUnsafeCopy (MV_6 _ as1 bs1 cs1 ds1 es1 fs1) (V_6 _ as2
+                                                          bs2
+                                                          cs2
+                                                          ds2
+                                                          es2
+                                                          fs2)
       = do
           G.basicUnsafeCopy as1 as2
           G.basicUnsafeCopy bs1 bs2
@@ -1013,7 +1048,7 @@
                      MVector s d ->
                      MVector s e ->
                      MVector s f -> MVector s (a, b, c, d, e, f)
-{-# INLINE_STREAM zip6 #-}
+{-# INLINE_FUSED zip6 #-}
 zip6 as bs cs ds es fs = MV_6 len (unsafeSlice 0 len as)
                                   (unsafeSlice 0 len bs)
                                   (unsafeSlice 0 len cs)
@@ -1040,7 +1075,7 @@
                                                         MVector s e,
                                                         MVector s f)
 {-# INLINE unzip6 #-}
-unzip6 (MV_6 n_ as bs cs ds es fs) = (as, bs, cs, ds, es, fs)
+unzip6 (MV_6 _ as bs cs ds es fs) = (as, bs, cs, ds, es, fs)
 #endif
 #ifdef DEFINE_IMMUTABLE
 -- | /O(1)/ Zip 6 vectors
@@ -1055,7 +1090,7 @@
                      Vector d ->
                      Vector e ->
                      Vector f -> Vector (a, b, c, d, e, f)
-{-# INLINE_STREAM zip6 #-}
+{-# INLINE_FUSED zip6 #-}
 zip6 as bs cs ds es fs = V_6 len (unsafeSlice 0 len as)
                                  (unsafeSlice 0 len bs)
                                  (unsafeSlice 0 len cs)
@@ -1075,13 +1110,13 @@
                  cs
                  ds
                  es
-                 fs) = Stream.zipWith6 (, , , , ,) (G.stream as)
+                 fs) = Bundle.zipWith6 (, , , , ,) (G.stream as)
                                                    (G.stream bs)
                                                    (G.stream cs)
                                                    (G.stream ds)
                                                    (G.stream es)
-                                                   (G.stream fs)
-  #-}
+                                                   (G.stream fs)   #-}
+
 -- | /O(1)/ Unzip 6 vectors
 unzip6 :: (Unbox a,
            Unbox b,
@@ -1095,5 +1130,5 @@
                                                      Vector e,
                                                      Vector f)
 {-# INLINE unzip6 #-}
-unzip6 (V_6 n_ as bs cs ds es fs) = (as, bs, cs, ds, es, fs)
+unzip6 (V_6 _ as bs cs ds es fs) = (as, bs, cs, ds, es, fs)
 #endif
diff --git a/tests/Main.hs b/tests/Main.hs
--- a/tests/Main.hs
+++ b/tests/Main.hs
@@ -1,12 +1,12 @@
 module Main (main) where
 
 import qualified Tests.Vector
-import qualified Tests.Stream
+import qualified Tests.Bundle
 import qualified Tests.Move
 
 import Test.Framework (defaultMain)
 
-main = defaultMain $ Tests.Stream.tests
+main = defaultMain $ Tests.Bundle.tests
                   ++ Tests.Vector.tests
                   ++ Tests.Move.tests
 
diff --git a/tests/Tests/Bundle.hs b/tests/Tests/Bundle.hs
new file mode 100644
--- /dev/null
+++ b/tests/Tests/Bundle.hs
@@ -0,0 +1,163 @@
+module Tests.Bundle ( tests ) where
+
+import Boilerplater
+import Utilities
+
+import qualified Data.Vector.Fusion.Bundle as S
+
+import Test.QuickCheck
+
+import Test.Framework
+import Test.Framework.Providers.QuickCheck2
+
+import Text.Show.Functions ()
+import Data.List           (foldl', foldl1', unfoldr, find, findIndex)
+import System.Random       (Random)
+
+#define COMMON_CONTEXT(a) \
+ VANILLA_CONTEXT(a)
+
+#define VANILLA_CONTEXT(a) \
+  Eq a,     Show a,     Arbitrary a,     CoArbitrary a,     TestData a,     Model a ~ a,        EqTest a ~ Property
+
+testSanity :: forall v a. (COMMON_CONTEXT(a)) => S.Bundle v a -> [Test]
+testSanity _ = [
+        testProperty "fromList.toList == id" prop_fromList_toList,
+        testProperty "toList.fromList == id" prop_toList_fromList
+    ]
+  where
+    prop_fromList_toList :: P (S.Bundle v a -> S.Bundle v a)
+        = (S.fromList . S.toList) `eq` id
+    prop_toList_fromList :: P ([a] -> [a])
+        = (S.toList . (S.fromList :: [a] -> S.Bundle v a)) `eq` id
+
+testPolymorphicFunctions :: forall v a. (COMMON_CONTEXT(a)) => S.Bundle v a -> [Test]
+testPolymorphicFunctions _ = $(testProperties [
+        'prop_eq,
+
+        'prop_length, 'prop_null,
+
+        'prop_empty, 'prop_singleton, 'prop_replicate,
+        'prop_cons, 'prop_snoc, 'prop_append,
+
+        'prop_head, 'prop_last, 'prop_index,
+
+        'prop_extract, 'prop_init, 'prop_tail, 'prop_take, 'prop_drop,
+
+        'prop_map, 'prop_zipWith, 'prop_zipWith3,
+        'prop_filter, 'prop_takeWhile, 'prop_dropWhile,
+
+        'prop_elem, 'prop_notElem,
+        'prop_find, 'prop_findIndex,
+
+        'prop_foldl, 'prop_foldl1, 'prop_foldl', 'prop_foldl1',
+        'prop_foldr, 'prop_foldr1,
+
+        'prop_prescanl, 'prop_prescanl',
+        'prop_postscanl, 'prop_postscanl',
+        'prop_scanl, 'prop_scanl', 'prop_scanl1, 'prop_scanl1',
+
+        'prop_concatMap,
+        'prop_unfoldr
+    ])
+  where
+    -- Prelude
+    prop_eq :: P (S.Bundle v a -> S.Bundle v a -> Bool) = (==) `eq` (==)
+
+    prop_length :: P (S.Bundle v a -> Int)     = S.length `eq` length
+    prop_null   :: P (S.Bundle v a -> Bool)    = S.null `eq` null
+    prop_empty  :: P (S.Bundle v a)            = S.empty `eq` []
+    prop_singleton :: P (a -> S.Bundle v a)    = S.singleton `eq` singleton
+    prop_replicate :: P (Int -> a -> S.Bundle v a)
+              = (\n _ -> n < 1000) ===> S.replicate `eq` replicate
+    prop_cons      :: P (a -> S.Bundle v a -> S.Bundle v a) = S.cons `eq` (:)
+    prop_snoc      :: P (S.Bundle v a -> a -> S.Bundle v a) = S.snoc `eq` snoc
+    prop_append    :: P (S.Bundle v a -> S.Bundle v a -> S.Bundle v a) = (S.++) `eq` (++)
+
+    prop_head      :: P (S.Bundle v a -> a) = not . S.null ===> S.head `eq` head
+    prop_last      :: P (S.Bundle v a -> a) = not . S.null ===> S.last `eq` last
+    prop_index        = \xs ->
+                        not (S.null xs) ==>
+                        forAll (choose (0, S.length xs-1)) $ \i ->
+                        unP prop xs i
+      where
+        prop :: P (S.Bundle v a -> Int -> a) = (S.!!) `eq` (!!)
+
+    prop_extract      = \xs ->
+                        forAll (choose (0, S.length xs))     $ \i ->
+                        forAll (choose (0, S.length xs - i)) $ \n ->
+                        unP prop i n xs
+      where
+        prop :: P (Int -> Int -> S.Bundle v a -> S.Bundle v a) = S.slice `eq` slice
+
+    prop_tail :: P (S.Bundle v a -> S.Bundle v a) = not . S.null ===> S.tail `eq` tail
+    prop_init :: P (S.Bundle v a -> S.Bundle v a) = not . S.null ===> S.init `eq` init
+    prop_take :: P (Int -> S.Bundle v a -> S.Bundle v a) = S.take `eq` take
+    prop_drop :: P (Int -> S.Bundle v a -> S.Bundle v a) = S.drop `eq` drop
+
+    prop_map :: P ((a -> a) -> S.Bundle v a -> S.Bundle v a) = S.map `eq` map
+    prop_zipWith :: P ((a -> a -> a) -> S.Bundle v a -> S.Bundle v a -> S.Bundle v a) = S.zipWith `eq` zipWith
+    prop_zipWith3 :: P ((a -> a -> a -> a) -> S.Bundle v a -> S.Bundle v a -> S.Bundle v a -> S.Bundle v a)
+             = S.zipWith3 `eq` zipWith3
+
+    prop_filter :: P ((a -> Bool) -> S.Bundle v a -> S.Bundle v a) = S.filter `eq` filter
+    prop_takeWhile :: P ((a -> Bool) -> S.Bundle v a -> S.Bundle v a) = S.takeWhile `eq` takeWhile
+    prop_dropWhile :: P ((a -> Bool) -> S.Bundle v a -> S.Bundle v a) = S.dropWhile `eq` dropWhile
+
+    prop_elem    :: P (a -> S.Bundle v a -> Bool) = S.elem `eq` elem
+    prop_notElem :: P (a -> S.Bundle v a -> Bool) = S.notElem `eq` notElem
+    prop_find    :: P ((a -> Bool) -> S.Bundle v a -> Maybe a) = S.find `eq` find
+    prop_findIndex :: P ((a -> Bool) -> S.Bundle v a -> Maybe Int)
+      = S.findIndex `eq` findIndex
+
+    prop_foldl :: P ((a -> a -> a) -> a -> S.Bundle v a -> a) = S.foldl `eq` foldl
+    prop_foldl1 :: P ((a -> a -> a) -> S.Bundle v a -> a)     = notNullS2 ===>
+                        S.foldl1 `eq` foldl1
+    prop_foldl' :: P ((a -> a -> a) -> a -> S.Bundle v a -> a) = S.foldl' `eq` foldl'
+    prop_foldl1' :: P ((a -> a -> a) -> S.Bundle v a -> a)     = notNullS2 ===>
+                        S.foldl1' `eq` foldl1'
+    prop_foldr :: P ((a -> a -> a) -> a -> S.Bundle v a -> a) = S.foldr `eq` foldr
+    prop_foldr1 :: P ((a -> a -> a) -> S.Bundle v a -> a)     = notNullS2 ===>
+                        S.foldr1 `eq` foldr1
+
+    prop_prescanl :: P ((a -> a -> a) -> a -> S.Bundle v a -> S.Bundle v a)
+                = S.prescanl `eq` prescanl
+    prop_prescanl' :: P ((a -> a -> a) -> a -> S.Bundle v a -> S.Bundle v a)
+                = S.prescanl' `eq` prescanl
+    prop_postscanl :: P ((a -> a -> a) -> a -> S.Bundle v a -> S.Bundle v a)
+                = S.postscanl `eq` postscanl
+    prop_postscanl' :: P ((a -> a -> a) -> a -> S.Bundle v a -> S.Bundle v a)
+                = S.postscanl' `eq` postscanl
+    prop_scanl :: P ((a -> a -> a) -> a -> S.Bundle v a -> S.Bundle v a)
+                = S.scanl `eq` scanl
+    prop_scanl' :: P ((a -> a -> a) -> a -> S.Bundle v a -> S.Bundle v a)
+               = S.scanl' `eq` scanl
+    prop_scanl1 :: P ((a -> a -> a) -> S.Bundle v a -> S.Bundle v a) = notNullS2 ===>
+                 S.scanl1 `eq` scanl1
+    prop_scanl1' :: P ((a -> a -> a) -> S.Bundle v a -> S.Bundle v a) = notNullS2 ===>
+                 S.scanl1' `eq` scanl1
+ 
+    prop_concatMap    = forAll arbitrary $ \xs ->
+                        forAll (sized (\n -> resize (n `div` S.length xs) arbitrary)) $ \f -> unP prop f xs
+      where
+        prop :: P ((a -> S.Bundle v a) -> S.Bundle v a -> S.Bundle v a) = S.concatMap `eq` concatMap
+
+    limitUnfolds f (theirs, ours) | ours >= 0
+                                  , Just (out, theirs') <- f theirs = Just (out, (theirs', ours - 1))
+                                  | otherwise                       = Nothing
+    prop_unfoldr :: P (Int -> (Int -> Maybe (a,Int)) -> Int -> S.Bundle v a)
+         = (\n f a -> S.unfoldr (limitUnfolds f) (a, n))
+           `eq` (\n f a -> unfoldr (limitUnfolds f) (a, n))
+
+testBoolFunctions :: forall v. S.Bundle v Bool -> [Test]
+testBoolFunctions _ = $(testProperties ['prop_and, 'prop_or ])
+  where
+    prop_and :: P (S.Bundle v Bool -> Bool) = S.and `eq` and
+    prop_or  :: P (S.Bundle v Bool -> Bool) = S.or `eq` or
+
+testBundleFunctions = testSanity (undefined :: S.Bundle v Int)
+                      ++ testPolymorphicFunctions (undefined :: S.Bundle v Int)
+                      ++ testBoolFunctions (undefined :: S.Bundle v Bool)
+
+tests = [ testGroup "Data.Vector.Fusion.Bundle" testBundleFunctions ]
+
diff --git a/tests/Tests/Move.hs b/tests/Tests/Move.hs
--- a/tests/Tests/Move.hs
+++ b/tests/Tests/Move.hs
@@ -4,7 +4,6 @@
 import Test.Framework.Providers.QuickCheck2
 import Test.QuickCheck.Property (Property(..))
 
-
 import Utilities ()
 
 import qualified Data.Vector.Generic as G
@@ -28,7 +27,6 @@
   expected <- return $ basicMove v dstOff srcOff len
   actual <- return $  G.modify (\ mv -> M.move (M.slice dstOff len mv) (M.slice srcOff len mv)) v
   unProperty $ counterexample ("Move: " ++ show (v, dstOff, srcOff, len)) (expected == actual))
-
 
 tests =
     [testProperty "Data.Vector.Mutable (Move)" (testMove :: V.Vector Int -> Property),
diff --git a/tests/Tests/Stream.hs b/tests/Tests/Stream.hs
deleted file mode 100644
--- a/tests/Tests/Stream.hs
+++ /dev/null
@@ -1,163 +0,0 @@
-module Tests.Stream ( tests ) where
-
-import Boilerplater
-import Utilities
-
-import qualified Data.Vector.Fusion.Stream as S
-
-import Test.QuickCheck
-
-import Test.Framework
-import Test.Framework.Providers.QuickCheck2
-
-import Text.Show.Functions ()
-import Data.List           (foldl', foldl1', unfoldr, find, findIndex)
-import System.Random       (Random)
-
-#define COMMON_CONTEXT(a) \
- VANILLA_CONTEXT(a)
-
-#define VANILLA_CONTEXT(a) \
-  Eq a,     Show a,     Arbitrary a,     CoArbitrary a,     TestData a,     Model a ~ a,        EqTest a ~ Property
-
-testSanity :: forall a. (COMMON_CONTEXT(a)) => S.Stream a -> [Test]
-testSanity _ = [
-        testProperty "fromList.toList == id" prop_fromList_toList,
-        testProperty "toList.fromList == id" prop_toList_fromList
-    ]
-  where
-    prop_fromList_toList :: P (S.Stream a -> S.Stream a)
-        = (S.fromList . S.toList) `eq` id
-    prop_toList_fromList :: P ([a] -> [a])
-        = (S.toList . (S.fromList :: [a] -> S.Stream a)) `eq` id
-
-testPolymorphicFunctions :: forall a. (COMMON_CONTEXT(a)) => S.Stream a -> [Test]
-testPolymorphicFunctions _ = $(testProperties [
-        'prop_eq,
-
-        'prop_length, 'prop_null,
-
-        'prop_empty, 'prop_singleton, 'prop_replicate,
-        'prop_cons, 'prop_snoc, 'prop_append,
-
-        'prop_head, 'prop_last, 'prop_index,
-
-        'prop_extract, 'prop_init, 'prop_tail, 'prop_take, 'prop_drop,
-
-        'prop_map, 'prop_zipWith, 'prop_zipWith3,
-        'prop_filter, 'prop_takeWhile, 'prop_dropWhile,
-
-        'prop_elem, 'prop_notElem,
-        'prop_find, 'prop_findIndex,
-
-        'prop_foldl, 'prop_foldl1, 'prop_foldl', 'prop_foldl1',
-        'prop_foldr, 'prop_foldr1,
-
-        'prop_prescanl, 'prop_prescanl',
-        'prop_postscanl, 'prop_postscanl',
-        'prop_scanl, 'prop_scanl', 'prop_scanl1, 'prop_scanl1',
-
-        'prop_concatMap,
-        'prop_unfoldr
-    ])
-  where
-    -- Prelude
-    prop_eq :: P (S.Stream a -> S.Stream a -> Bool) = (==) `eq` (==)
-
-    prop_length :: P (S.Stream a -> Int)     = S.length `eq` length
-    prop_null   :: P (S.Stream a -> Bool)    = S.null `eq` null
-    prop_empty  :: P (S.Stream a)            = S.empty `eq` []
-    prop_singleton :: P (a -> S.Stream a)    = S.singleton `eq` singleton
-    prop_replicate :: P (Int -> a -> S.Stream a)
-              = (\n _ -> n < 1000) ===> S.replicate `eq` replicate
-    prop_cons      :: P (a -> S.Stream a -> S.Stream a) = S.cons `eq` (:)
-    prop_snoc      :: P (S.Stream a -> a -> S.Stream a) = S.snoc `eq` snoc
-    prop_append    :: P (S.Stream a -> S.Stream a -> S.Stream a) = (S.++) `eq` (++)
-
-    prop_head      :: P (S.Stream a -> a) = not . S.null ===> S.head `eq` head
-    prop_last      :: P (S.Stream a -> a) = not . S.null ===> S.last `eq` last
-    prop_index        = \xs ->
-                        not (S.null xs) ==>
-                        forAll (choose (0, S.length xs-1)) $ \i ->
-                        unP prop xs i
-      where
-        prop :: P (S.Stream a -> Int -> a) = (S.!!) `eq` (!!)
-
-    prop_extract      = \xs ->
-                        forAll (choose (0, S.length xs))     $ \i ->
-                        forAll (choose (0, S.length xs - i)) $ \n ->
-                        unP prop i n xs
-      where
-        prop :: P (Int -> Int -> S.Stream a -> S.Stream a) = S.slice `eq` slice
-
-    prop_tail :: P (S.Stream a -> S.Stream a) = not . S.null ===> S.tail `eq` tail
-    prop_init :: P (S.Stream a -> S.Stream a) = not . S.null ===> S.init `eq` init
-    prop_take :: P (Int -> S.Stream a -> S.Stream a) = S.take `eq` take
-    prop_drop :: P (Int -> S.Stream a -> S.Stream a) = S.drop `eq` drop
-
-    prop_map :: P ((a -> a) -> S.Stream a -> S.Stream a) = S.map `eq` map
-    prop_zipWith :: P ((a -> a -> a) -> S.Stream a -> S.Stream a -> S.Stream a) = S.zipWith `eq` zipWith
-    prop_zipWith3 :: P ((a -> a -> a -> a) -> S.Stream a -> S.Stream a -> S.Stream a -> S.Stream a)
-             = S.zipWith3 `eq` zipWith3
-
-    prop_filter :: P ((a -> Bool) -> S.Stream a -> S.Stream a) = S.filter `eq` filter
-    prop_takeWhile :: P ((a -> Bool) -> S.Stream a -> S.Stream a) = S.takeWhile `eq` takeWhile
-    prop_dropWhile :: P ((a -> Bool) -> S.Stream a -> S.Stream a) = S.dropWhile `eq` dropWhile
-
-    prop_elem    :: P (a -> S.Stream a -> Bool) = S.elem `eq` elem
-    prop_notElem :: P (a -> S.Stream a -> Bool) = S.notElem `eq` notElem
-    prop_find    :: P ((a -> Bool) -> S.Stream a -> Maybe a) = S.find `eq` find
-    prop_findIndex :: P ((a -> Bool) -> S.Stream a -> Maybe Int)
-      = S.findIndex `eq` findIndex
-
-    prop_foldl :: P ((a -> a -> a) -> a -> S.Stream a -> a) = S.foldl `eq` foldl
-    prop_foldl1 :: P ((a -> a -> a) -> S.Stream a -> a)     = notNullS2 ===>
-                        S.foldl1 `eq` foldl1
-    prop_foldl' :: P ((a -> a -> a) -> a -> S.Stream a -> a) = S.foldl' `eq` foldl'
-    prop_foldl1' :: P ((a -> a -> a) -> S.Stream a -> a)     = notNullS2 ===>
-                        S.foldl1' `eq` foldl1'
-    prop_foldr :: P ((a -> a -> a) -> a -> S.Stream a -> a) = S.foldr `eq` foldr
-    prop_foldr1 :: P ((a -> a -> a) -> S.Stream a -> a)     = notNullS2 ===>
-                        S.foldr1 `eq` foldr1
-
-    prop_prescanl :: P ((a -> a -> a) -> a -> S.Stream a -> S.Stream a)
-                = S.prescanl `eq` prescanl
-    prop_prescanl' :: P ((a -> a -> a) -> a -> S.Stream a -> S.Stream a)
-                = S.prescanl' `eq` prescanl
-    prop_postscanl :: P ((a -> a -> a) -> a -> S.Stream a -> S.Stream a)
-                = S.postscanl `eq` postscanl
-    prop_postscanl' :: P ((a -> a -> a) -> a -> S.Stream a -> S.Stream a)
-                = S.postscanl' `eq` postscanl
-    prop_scanl :: P ((a -> a -> a) -> a -> S.Stream a -> S.Stream a)
-                = S.scanl `eq` scanl
-    prop_scanl' :: P ((a -> a -> a) -> a -> S.Stream a -> S.Stream a)
-               = S.scanl' `eq` scanl
-    prop_scanl1 :: P ((a -> a -> a) -> S.Stream a -> S.Stream a) = notNullS2 ===>
-                 S.scanl1 `eq` scanl1
-    prop_scanl1' :: P ((a -> a -> a) -> S.Stream a -> S.Stream a) = notNullS2 ===>
-                 S.scanl1' `eq` scanl1
- 
-    prop_concatMap    = forAll arbitrary $ \xs ->
-                        forAll (sized (\n -> resize (n `div` S.length xs) arbitrary)) $ \f -> unP prop f xs
-      where
-        prop :: P ((a -> S.Stream a) -> S.Stream a -> S.Stream a) = S.concatMap `eq` concatMap
-
-    limitUnfolds f (theirs, ours) | ours >= 0
-                                  , Just (out, theirs') <- f theirs = Just (out, (theirs', ours - 1))
-                                  | otherwise                       = Nothing
-    prop_unfoldr :: P (Int -> (Int -> Maybe (a,Int)) -> Int -> S.Stream a)
-         = (\n f a -> S.unfoldr (limitUnfolds f) (a, n))
-           `eq` (\n f a -> unfoldr (limitUnfolds f) (a, n))
-
-testBoolFunctions :: [Test]
-testBoolFunctions = $(testProperties ['prop_and, 'prop_or])
-  where
-    prop_and :: P (S.Stream Bool -> Bool) = S.and `eq` and
-    prop_or  :: P (S.Stream Bool -> Bool) = S.or `eq` or
-
-testStreamFunctions = testSanity (undefined :: S.Stream Int)
-                      ++ testPolymorphicFunctions (undefined :: S.Stream Int)
-                      ++ testBoolFunctions
-
-tests = [ testGroup "Data.Vector.Fusion.Stream" testStreamFunctions ]
-
diff --git a/tests/Tests/Vector.hs b/tests/Tests/Vector.hs
--- a/tests/Tests/Vector.hs
+++ b/tests/Tests/Vector.hs
@@ -8,7 +8,7 @@
 import qualified Data.Vector.Primitive
 import qualified Data.Vector.Storable
 import qualified Data.Vector.Unboxed
-import qualified Data.Vector.Fusion.Stream as S
+import qualified Data.Vector.Fusion.Bundle as S
 
 import Test.QuickCheck
 
@@ -21,6 +21,9 @@
 import qualified Control.Applicative as Applicative
 import System.Random       (Random)
 
+import Data.Functor.Identity
+import Control.Monad.Trans.Writer
+
 #define COMMON_CONTEXT(a, v) \
  VANILLA_CONTEXT(a, v), VECTOR_CONTEXT(a, v)
 
@@ -74,7 +77,7 @@
     prop_fromList_toList (v :: v a)        = (V.fromList . V.toList)                        v == v
     prop_toList_fromList (l :: [a])        = ((V.toList :: v a -> [a]) . V.fromList)        l == l
     prop_unstream_stream (v :: v a)        = (V.unstream . V.stream)                        v == v
-    prop_stream_unstream (s :: S.Stream a) = ((V.stream :: v a -> S.Stream a) . V.unstream) s == s
+    prop_stream_unstream (s :: S.Bundle v a) = ((V.stream :: v a -> S.Bundle v a) . V.unstream) s == s
 
 testPolymorphicFunctions :: forall a v. (COMMON_CONTEXT(a, v), VECTOR_CONTEXT(Int, v)) => v a -> [Test]
 testPolymorphicFunctions _ = $(testProperties [
@@ -140,10 +143,12 @@
 
         -- Monadic mapping
         {- 'prop_mapM, 'prop_mapM_, 'prop_forM, 'prop_forM_, -}
+        'prop_imapM, 'prop_imapM_,
 
         -- Zipping
         'prop_zipWith, 'prop_zipWith3, {- ... -}
         'prop_izipWith, 'prop_izipWith3, {- ... -}
+        'prop_izipWithM, 'prop_izipWithM_,
         {- 'prop_zip, ... -}
 
         -- Monadic zipping
@@ -169,6 +174,7 @@
         'prop_foldl, 'prop_foldl1, 'prop_foldl', 'prop_foldl1',
         'prop_foldr, 'prop_foldr1, 'prop_foldr', 'prop_foldr1',
         'prop_ifoldl, 'prop_ifoldl', 'prop_ifoldr, 'prop_ifoldr',
+        'prop_ifoldM, 'prop_ifoldM', 'prop_ifoldM_, 'prop_ifoldM'_,
 
         -- Specialised folds
         'prop_all, 'prop_any,
@@ -272,7 +278,15 @@
     prop_zipWith3 :: P ((a -> a -> a -> a) -> v a -> v a -> v a -> v a)
              = V.zipWith3 `eq` zipWith3
     prop_imap :: P ((Int -> a -> a) -> v a -> v a) = V.imap `eq` imap
+    prop_imapM :: P ((Int -> a -> Identity a) -> v a -> Identity (v a))
+            = V.imapM `eq` imapM
+    prop_imapM_ :: P ((Int -> a -> Writer [a] ()) -> v a -> Writer [a] ())
+            = V.imapM_ `eq` imapM_
     prop_izipWith :: P ((Int -> a -> a -> a) -> v a -> v a -> v a) = V.izipWith `eq` izipWith
+    prop_izipWithM :: P ((Int -> a -> a -> Identity a) -> v a -> v a -> Identity (v a))
+            = V.izipWithM `eq` izipWithM
+    prop_izipWithM_ :: P ((Int -> a -> a -> Writer [a] ()) -> v a -> v a -> Writer [a] ())
+            = V.izipWithM_ `eq` izipWithM_
     prop_izipWith3 :: P ((Int -> a -> a -> a -> a) -> v a -> v a -> v a -> v a)
              = V.izipWith3 `eq` izipWith3
 
@@ -315,6 +329,14 @@
         = V.ifoldr `eq` ifoldr
     prop_ifoldr' :: P ((Int -> a -> a -> a) -> a -> v a -> a)
         = V.ifoldr' `eq` ifoldr
+    prop_ifoldM :: P ((a -> Int -> a -> Identity a) -> a -> v a -> Identity a)
+        = V.ifoldM `eq` ifoldM
+    prop_ifoldM' :: P ((a -> Int -> a -> Identity a) -> a -> v a -> Identity a)
+        = V.ifoldM' `eq` ifoldM
+    prop_ifoldM_ :: P ((() -> Int -> a -> Writer [a] ()) -> () -> v a -> Writer [a] ())
+        = V.ifoldM_ `eq` ifoldM_
+    prop_ifoldM'_ :: P ((() -> Int -> a -> Writer [a] ()) -> () -> v a -> Writer [a] ())
+        = V.ifoldM'_ `eq` ifoldM_
 
     prop_all :: P ((a -> Bool) -> v a -> Bool) = V.all `eq` all
     prop_any :: P ((a -> Bool) -> v a -> Bool) = V.any `eq` any
diff --git a/tests/Utilities.hs b/tests/Utilities.hs
--- a/tests/Utilities.hs
+++ b/tests/Utilities.hs
@@ -8,13 +8,17 @@
 import qualified Data.Vector.Primitive as DVP
 import qualified Data.Vector.Storable as DVS
 import qualified Data.Vector.Unboxed as DVU
-import qualified Data.Vector.Fusion.Stream as S
+import qualified Data.Vector.Fusion.Bundle as S
 
+import Control.Monad (foldM, foldM_, zipWithM, zipWithM_)
+import Control.Monad.Trans.Writer
+import Data.Function (on)
+import Data.Functor.Identity
 import Data.List ( sortBy )
-
+import Data.Monoid
 
-instance Show a => Show (S.Stream a) where
-    show s = "Data.Vector.Fusion.Stream.fromList " ++ show (S.toList s)
+instance Show a => Show (S.Bundle v a) where
+    show s = "Data.Vector.Fusion.Bundle.fromList " ++ show (S.toList s)
 
 
 instance Arbitrary a => Arbitrary (DV.Vector a) where
@@ -41,12 +45,24 @@
 instance (CoArbitrary a, DVU.Unbox a) => CoArbitrary (DVU.Vector a) where
     coarbitrary = coarbitrary . DVU.toList
 
-instance Arbitrary a => Arbitrary (S.Stream a) where
+instance Arbitrary a => Arbitrary (S.Bundle v a) where
     arbitrary = fmap S.fromList arbitrary
 
-instance CoArbitrary a => CoArbitrary (S.Stream a) where
+instance CoArbitrary a => CoArbitrary (S.Bundle v a) where
     coarbitrary = coarbitrary . S.toList
 
+instance Arbitrary a => Arbitrary (Identity a) where
+    arbitrary = fmap Identity arbitrary
+
+instance CoArbitrary a => CoArbitrary (Identity a) where
+    coarbitrary = coarbitrary . runIdentity
+
+instance Arbitrary a => Arbitrary (Writer a ()) where
+    arbitrary = fmap (writer . ((,) ())) arbitrary
+
+instance CoArbitrary a => CoArbitrary (Writer a ()) where
+    coarbitrary = coarbitrary . runWriter
+
 class (Testable (EqTest a), Conclusion (EqTest a)) => TestData a where
   type Model a
   model :: a -> Model a
@@ -55,12 +71,12 @@
   type EqTest a
   equal :: a -> a -> EqTest a
 
-instance Eq a => TestData (S.Stream a) where
-  type Model (S.Stream a) = [a]
+instance Eq a => TestData (S.Bundle v a) where
+  type Model (S.Bundle v a) = [a]
   model = S.toList
   unmodel = S.fromList
 
-  type EqTest (S.Stream a) = Property
+  type EqTest (S.Bundle v a) = Property
   equal x y = property (x == y)
 
 instance Eq a => TestData (DV.Vector a) where
@@ -129,6 +145,22 @@
   type EqTest [a] = Property
   equal x y = property (x == y)
 
+instance (Eq a, TestData a) => TestData (Identity a) where
+  type Model (Identity a) = Identity (Model a)
+  model = fmap model
+  unmodel = fmap unmodel
+
+  type EqTest (Identity a) = Property
+  equal = (property .) . on (==) runIdentity
+
+instance (Eq a, TestData a, Monoid a) => TestData (Writer a ()) where
+  type Model (Writer a ()) = Writer (Model a) ()
+  model = mapWriter model
+  unmodel = mapWriter unmodel
+
+  type EqTest (Writer a ()) = Property
+  equal = (property .) . on (==) execWriter
+
 instance (Eq a, Eq b, TestData a, TestData b) => TestData (a,b) where
   type Model (a,b) = (Model a, Model b)
   model (a,b) = (model a, model b)
@@ -233,23 +265,46 @@
     go (x:xs) ps j = x : go xs ps (j+1)
     go [] _ _      = []
 
+
+withIndexFirst m f = m (uncurry f) . zip [0..]
+
 imap :: (Int -> a -> a) -> [a] -> [a]
-imap f = map (uncurry f) . zip [0..]
+imap = withIndexFirst map
 
+imapM :: Monad m => (Int -> a -> m a) -> [a] -> m [a]
+imapM = withIndexFirst mapM
+
+imapM_ :: Monad m => (Int -> a -> m b) -> [a] -> m ()
+imapM_ = withIndexFirst mapM_
+
 izipWith :: (Int -> a -> a -> a) -> [a] -> [a] -> [a]
-izipWith f = zipWith (uncurry f) . zip [0..]
+izipWith = withIndexFirst zipWith
 
+izipWithM :: Monad m => (Int -> a -> a -> m a) -> [a] -> [a] -> m [a]
+izipWithM = withIndexFirst zipWithM
+
+izipWithM_ :: Monad m => (Int -> a -> a -> m b) -> [a] -> [a] -> m ()
+izipWithM_ = withIndexFirst zipWithM_
+
 izipWith3 :: (Int -> a -> a -> a -> a) -> [a] -> [a] -> [a] -> [a]
-izipWith3 f = zipWith3 (uncurry f) . zip [0..]
+izipWith3 = withIndexFirst zipWith3
 
 ifilter :: (Int -> a -> Bool) -> [a] -> [a]
-ifilter f = map snd . filter (uncurry f) . zip [0..]
+ifilter f = map snd . withIndexFirst filter f
 
+indexedLeftFold fld f z = fld (uncurry . f) z . zip [0..]
+
 ifoldl :: (a -> Int -> a -> a) -> a -> [a] -> a
-ifoldl f z = foldl (uncurry . f) z . zip [0..]
+ifoldl = indexedLeftFold foldl
 
 ifoldr :: (Int -> a -> b -> b) -> b -> [a] -> b
 ifoldr f z = foldr (uncurry f) z . zip [0..]
+
+ifoldM :: Monad m => (a -> Int -> a -> m a) -> a -> [a] -> m a
+ifoldM = indexedLeftFold foldM
+
+ifoldM_ :: Monad m => (b -> Int -> a -> m b) -> b -> [a] -> m ()
+ifoldM_ = indexedLeftFold foldM_
 
 minIndex :: Ord a => [a] -> Int
 minIndex = fst . foldr1 imin . zip [0..]
diff --git a/vector.cabal b/vector.cabal
--- a/vector.cabal
+++ b/vector.cabal
@@ -1,10 +1,10 @@
 Name:           vector
-Version:        0.10.12.3
+Version:        0.11.0.0
 -- don't forget to update the changelog file!
 License:        BSD3
 License-File:   LICENSE
 Author:         Roman Leshchinskiy <rl@cse.unsw.edu.au>
-Maintainer:     libraries@haskell.org
+Maintainer:     Haskell Libraries Team <libraries@haskell.org>
 Copyright:      (c) Roman Leshchinskiy 2008-2012
 Homepage:       https://github.com/haskell/vector
 Bug-Reports:    https://github.com/haskell/vector/issues
@@ -34,7 +34,7 @@
         .
         * <http://haskell.org/haskellwiki/Numeric_Haskell:_A_Vector_Tutorial>
 
-Cabal-Version:  >= 1.10
+Cabal-Version:  >=1.10
 Build-Type:     Simple
 
 Extra-Source-Files:
@@ -45,7 +45,7 @@
       tests/Boilerplater.hs
       tests/Utilities.hs
       tests/Tests/Move.hs
-      tests/Tests/Stream.hs
+      tests/Tests/Bundle.hs
       tests/Tests/Vector.hs
       benchmarks/vector-benchmarks.cabal
       benchmarks/LICENSE
@@ -86,15 +86,32 @@
 
 Library
   Default-Language: Haskell2010
-  Default-Extensions: CPP, DeriveDataTypeable
+  Other-Extensions:
+        BangPatterns
+        CPP
+        DeriveDataTypeable
+        ExistentialQuantification
+        FlexibleContexts
+        FlexibleInstances
+        GADTs
+        KindSignatures
+        MagicHash
+        MultiParamTypeClasses
+        Rank2Types
+        ScopedTypeVariables
+        StandaloneDeriving
+        TypeFamilies
+
   Exposed-Modules:
         Data.Vector.Internal.Check
 
         Data.Vector.Fusion.Util
-        Data.Vector.Fusion.Stream.Size
         Data.Vector.Fusion.Stream.Monadic
-        Data.Vector.Fusion.Stream
+        Data.Vector.Fusion.Bundle.Size
+        Data.Vector.Fusion.Bundle.Monadic
+        Data.Vector.Fusion.Bundle
 
+        Data.Vector.Generic.Mutable.Base
         Data.Vector.Generic.Mutable
         Data.Vector.Generic.Base
         Data.Vector.Generic.New
@@ -120,15 +137,12 @@
   Install-Includes:
         vector.h
 
-  Build-Depends: base >= 4 && < 5
+  Build-Depends: base >= 4.3 && < 4.9
                , primitive >= 0.5.0.1 && < 0.7
-               , ghc-prim
+               , ghc-prim >= 0.2 && < 0.5
                , deepseq >= 1.1 && < 1.5
 
-  if impl(ghc<6.13)
-    Ghc-Options: -finline-if-enough-args -fno-method-sharing
-
-  Ghc-Options: -O2
+  Ghc-Options: -O2 -Wall -fno-warn-orphans
 
   if flag(BoundsChecks)
     cpp-options: -DVECTOR_BOUNDS_CHECKS
@@ -143,6 +157,8 @@
   type:     git
   location: https://github.com/haskell/vector.git
 
+
+
 test-suite vector-tests-O0
   Default-Language: Haskell2010
   type: exitcode-stdio-1.0
@@ -152,6 +168,7 @@
                  random,
                  QuickCheck >=  2.7  && < 2.8 , test-framework, test-framework-quickcheck2,
                  transformers >= 0.2.0.0
+
   default-extensions: CPP,
               ScopedTypeVariables,
               PatternGuards,
@@ -161,6 +178,7 @@
               TypeSynonymInstances,
               TypeFamilies,
               TemplateHaskell
+
   Ghc-Options: -O0
   Ghc-Options: -Wall -fno-warn-orphans -fno-warn-missing-signatures
 
@@ -173,6 +191,7 @@
                  random,
                  QuickCheck  >= 2.7, test-framework, test-framework-quickcheck2,
                  transformers >= 0.2.0.0
+
   default-extensions: CPP,
               ScopedTypeVariables,
               PatternGuards,
@@ -182,5 +201,6 @@
               TypeSynonymInstances,
               TypeFamilies,
               TemplateHaskell
+
   Ghc-Options: -O2
   Ghc-Options: -Wall -fno-warn-orphans -fno-warn-missing-signatures
