Remove MonadIO constraint from pure array getIndices

Author: harendra-kumar

src/Streamly/Internal/Data/Array/Foreign.hs

@@ -150,8 +150,6 @@ import qualified Streamly.Internal.Data.Stream.StreamD as D
 import qualified Streamly.Internal.Data.Unfold as Unfold
 import qualified Streamly.Internal.Data.Ring.Foreign as RB
 
-
-
 -------------------------------------------------------------------------------
 -- Construction
 -------------------------------------------------------------------------------
@@ -462,9 +460,10 @@ getIndex arr i =
 --
 -- /Pre-release/
 {-# INLINE getIndices #-}
-getIndices :: (MonadIO m, Storable a)
-    => SerialT m Int -> Unfold m (Array a) a
-getIndices st = Unfold.lmap A.unsafeThaw (MA.getIndices st)
+getIndices :: (Monad m, Storable a) => SerialT m Int -> Unfold m (Array a) a
+getIndices (SerialT stream) =
+    let unf = MA.getIndicesD (return . unsafeInlineIO) $ D.fromStreamK stream
+     in Unfold.lmap A.unsafeThaw unf
 
 -- | Unfolds @(from, then, to, array)@ generating a finite stream whose first
 -- element is the array value from the index @from@ and the successive elements

src/Streamly/Internal/Data/Array/Foreign/Mut/Type.hs

@@ -114,6 +114,7 @@ module Streamly.Internal.Data.Array.Foreign.Mut.Type
     , getIndex
     , getIndexUnsafe
     , getIndices
+    , getIndicesD
     -- , getFromThenTo
     , getIndexRev
 
@@ -1092,9 +1093,9 @@ data GetIndicesState contents start end st =
 --
 -- /Pre-release/
 {-# INLINE getIndicesD #-}
-getIndicesD :: (MonadIO m, Storable a) =>
-    D.Stream m Int -> Unfold m (Array a) a
-getIndicesD (D.Stream stepi sti) = Unfold step inject
+getIndicesD :: (Monad m, Storable a) =>
+    (forall b. IO b -> m b) -> D.Stream m Int -> Unfold m (Array a) a
+getIndicesD liftio (D.Stream stepi sti) = Unfold step inject
 
     where
 
@@ -1106,16 +1107,16 @@ getIndicesD (D.Stream stepi sti) = Unfold step inject
         r <- stepi defState st
         case r of
             D.Yield i s -> do
-                x <- liftIO $ getIndexPtr start end i
+                x <- liftio $ getIndexPtr start end i
                 return $ D.Yield x (GetIndicesState contents start end s)
             D.Skip s -> return $ D.Skip (GetIndicesState contents start end s)
             D.Stop -> do
-                liftIO $ touch contents
+                liftio $ touch contents
                 return D.Stop
 
 {-# INLINE getIndices #-}
 getIndices :: (MonadIO m, Storable a) => SerialT m Int -> Unfold m (Array a) a
-getIndices (SerialT stream) = getIndicesD $ D.fromStreamK stream
+getIndices (SerialT stream) = getIndicesD liftIO $ D.fromStreamK stream
 
 -------------------------------------------------------------------------------
 -- Subarrays