Change allocation strategy for unfoldrN & add warning for fromListN

vector/src/Data/Vector.hs

@@ -2119,7 +2119,11 @@ fromList :: [a] -> Vector a
 {-# INLINE fromList #-}
 fromList = G.fromList
 
--- | /O(n)/ Convert the first @n@ elements of a list to a vector.
+-- | /O(n)/ Convert the first @n@ elements of a list to a vector. It's
+-- expected that the supplied list will be exactly @n@ elements long. As
+-- an optimization, this function allocates a buffer for @n@ elements, which
+-- could be used for DoS-attacks by exhausting the memory if an attacker controls
+-- that parameter.
 --
 -- @
 -- fromListN n xs = 'fromList' ('take' n xs)

vector/src/Data/Vector/Fusion/Bundle/Monadic.hs

@@ -664,7 +664,7 @@ unfoldrN n f = unfoldrNM n (return . f)
 -- | Unfold at most @n@ elements with a monadic function.
 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))
+unfoldrNM n f s = fromStream (S.unfoldrNM n f s) Unknown
 
 -- | Unfold exactly @n@ elements
 --

vector/src/Data/Vector/Generic.hs

@@ -2297,7 +2297,11 @@ fromList :: Vector v a => [a] -> v a
 {-# INLINE fromList #-}
 fromList = unstream . Bundle.fromList
 
--- | /O(n)/ Convert the first @n@ elements of a list to a vector.
+-- | /O(n)/ Convert the first @n@ elements of a list to a vector. It's
+-- expected that the supplied list will be exactly @n@ elements long. As
+-- an optimization, this function allocates a buffer for @n@ elements, which
+-- could be used for DoS-attacks by exhausting the memory if an attacker controls
+-- that parameter.
 --
 -- @
 -- fromListN n xs = 'fromList' ('take' n xs)

vector/src/Data/Vector/Primitive.hs

@@ -1786,7 +1786,11 @@ fromList :: Prim a => [a] -> Vector a
 {-# INLINE fromList #-}
 fromList = G.fromList
 
--- | /O(n)/ Convert the first @n@ elements of a list to a vector.
+-- | /O(n)/ Convert the first @n@ elements of a list to a vector. It's
+-- expected that the supplied list will be exactly @n@ elements long. As
+-- an optimization, this function allocates a buffer for @n@ elements, which
+-- could be used for DoS-attacks by exhausting the memory if an attacker controls
+-- that parameter.
 --
 -- @
 -- fromListN n xs = 'fromList' ('take' n xs)

vector/src/Data/Vector/Storable.hs

@@ -1832,7 +1832,11 @@ fromList :: Storable a => [a] -> Vector a
 {-# INLINE fromList #-}
 fromList = G.fromList
 
--- | /O(n)/ Convert the first @n@ elements of a list to a vector.
+-- | /O(n)/ Convert the first @n@ elements of a list to a vector. It's
+-- expected that the supplied list will be exactly @n@ elements long. As
+-- an optimization, this function allocates a buffer for @n@ elements, which
+-- could be used for DoS-attacks by exhausting the memory if an attacker controls
+-- that parameter.
 --
 -- @
 -- fromListN n xs = 'fromList' ('take' n xs)

vector/src/Data/Vector/Unboxed.hs

@@ -1878,7 +1878,11 @@ fromList :: Unbox a => [a] -> Vector a
 {-# INLINE fromList #-}
 fromList = G.fromList
 
--- | /O(n)/ Convert the first @n@ elements of a list to a vector.
+-- | /O(n)/ Convert the first @n@ elements of a list to a vector. It's
+-- expected that the supplied list will be exactly @n@ elements long. As
+-- an optimization, this function allocates a buffer for @n@ elements, which
+-- could be used for DoS-attacks by exhausting the memory if an attacker controls
+-- that parameter.
 --
 -- @
 -- fromListN n xs = 'fromList' ('take' n xs)