Document which of mutable-copy's argument is the target, and which is the source

Author: Peaker

Data/Vector/Generic/Mutable.hs

@@ -768,8 +768,9 @@ set = basicSet
 
 -- | Copy a vector. The two vectors must have the same length and may not
 -- overlap.
-copy :: (PrimMonad m, MVector v a)
-                => v (PrimState m) a -> v (PrimState m) a -> m ()
+copy :: (PrimMonad m, MVector v a) => v (PrimState m) a   -- ^ target
+                                   -> v (PrimState m) a   -- ^ source
+                                   -> m ()
 {-# INLINE copy #-}
 copy dst src = BOUNDS_CHECK(check) "copy" "overlapping vectors"
                                           (not (dst `overlaps` src))

Data/Vector/Primitive/Mutable.hs

@@ -317,7 +317,9 @@ set = G.set
 -- | Copy a vector. The two vectors must have the same length and may not
 -- overlap.
 copy :: (PrimMonad m, Prim a)
-                 => MVector (PrimState m) a -> MVector (PrimState m) a -> m ()
+     => MVector (PrimState m) a   -- ^ target
+     -> MVector (PrimState m) a   -- ^ source
+     -> m ()
 {-# INLINE copy #-}
 copy = G.copy
 

Data/Vector/Storable/Mutable.hs

@@ -401,7 +401,9 @@ set = G.set
 -- | Copy a vector. The two vectors must have the same length and may not
 -- overlap.
 copy :: (PrimMonad m, Storable a)
-                 => MVector (PrimState m) a -> MVector (PrimState m) a -> m ()
+     => MVector (PrimState m) a   -- ^ target
+     -> MVector (PrimState m) a   -- ^ source
+     -> m ()
 {-# INLINE copy #-}
 copy = G.copy
 

Data/Vector/Unboxed/Mutable.hs

@@ -255,7 +255,9 @@ set = G.set
 -- | Copy a vector. The two vectors must have the same length and may not
 -- overlap.
 copy :: (PrimMonad m, Unbox a)
-                 => MVector (PrimState m) a -> MVector (PrimState m) a -> m ()
+     => MVector (PrimState m) a   -- ^ target
+     -> MVector (PrimState m) a   -- ^ source
+     -> m ()
 {-# INLINE copy #-}
 copy = G.copy