expose copy operation for Boxed Array and Strings

Foundation/Array/Boxed.hs

@@ -13,6 +13,7 @@
 module Foundation.Array.Boxed
     ( Array
     , MArray
+    , copy
     ) where
 
 import           GHC.Prim
@@ -226,6 +227,10 @@ freeze marray = do
   where
     sz = Size $ mutableLength marray
 
+-- | Copy the element to a new element array
+copy :: Array ty -> Array ty
+copy a = runST (unsafeThaw a >>= freeze)
+
 -- | Copy a number of elements from an array to another array with offsets
 copyAt :: PrimMonad prim
        => MArray ty (PrimState prim) -- ^ destination array

Foundation/String/UTF8.hs

@@ -33,6 +33,7 @@ module Foundation.String.UTF8
     , fromBytesLenient
     , toBytes
     , mutableValidate
+    , copy
     , ValidationFailure(..)
     -- * Legacy utility
     , lines
@@ -461,13 +462,13 @@ sToList s = loop azero
   #-}
 
 sFromList :: [Char] -> String
-sFromList l = runST (new bytes >>= copy)
+sFromList l = runST (new bytes >>= startCopy)
   where
     -- count how many bytes
     !bytes = C.foldl' (+) (Size 0) $ fmap (charToBytes . fromEnum) l
 
-    copy :: MutableString (PrimState (ST st)) -> ST st String
-    copy ms = loop azero l
+    startCopy :: MutableString (PrimState (ST st)) -> ST st String
+    startCopy ms = loop azero l
       where
         loop _   []     = freeze ms
         loop idx (c:xs) = write ms idx c >>= \idx' -> loop idx' xs
@@ -671,6 +672,10 @@ sizeBytes :: String -> Int
 sizeBytes (String ba) = I# (sizeofByteArray# ba)
 -}
 
+-- | Copy the String
+copy :: String -> String
+copy (String s) = String (Vec.copy s)
+
 -- | Allocate a MutableString of a specific size in bytes.
 new :: PrimMonad prim
     => Size8 -- ^ in number of bytes, not of elements.