3 files changed, 41 insertions, 9 deletions
diff --git a/src/Data/Array/Mixed.hs b/src/Data/Array/Mixed.hs
index 246f8fc..e7d2b69 100644
--- a/src/Data/Array/Mixed.hs
+++ b/src/Data/Array/Mixed.hs
@@ -360,3 +360,6 @@ fromList ssh l
         error $ "Data.Array.Mixed.fromList: length of list (" ++ show (length l) ++ ")" ++
                 "does not match the type (" ++ show (natVal m) ++ ")" 
       _ -> XArray (S.ravel (ORB.fromList [length l] (coerce @[XArray sh a] @[S.Array (FromINat (Rank sh)) a] l)))
+
+toList :: Storable a => XArray (n : sh) a -> [XArray sh a]
+toList (XArray arr) = coerce (ORB.toList (S.unravel arr))
diff --git a/src/Data/Array/Nested.hs b/src/Data/Array/Nested.hs
index 8fadef6..ee007e9 100644
--- a/src/Data/Array/Nested.hs
+++ b/src/Data/Array/Nested.hs
@@ -5,7 +5,7 @@ module Data.Array.Nested (
   IxR(..),
   rshape, rindex, rindexPartial, rgenerate, rsumOuter1,
   rtranspose, rappend, rscalar, rfromVector, runScalar,
-  rconstant, rfromList, rfromList1,
+  rconstant, rfromList, rfromList1, rtoList, rtoList1,
   -- ** Lifting orthotope operations to 'Ranked' arrays
   rlift,
 
@@ -15,7 +15,7 @@ module Data.Array.Nested (
   KnownShape(..), SShape(..),
   sshape, sindex, sindexPartial, sgenerate, ssumOuter1,
   stranspose, sappend, sscalar, sfromVector, sunScalar,
-  sconstant, sfromList, sfromList1,
+  sconstant, sfromList, sfromList1, stoList, stoList1,
   -- ** Lifting orthotope operations to 'Shaped' arrays
   slift,
 
@@ -24,10 +24,10 @@ module Data.Array.Nested (
   IxX(..),
   KnownShapeX(..), StaticShapeX(..),
   mgenerate, mtranspose, mappend, mfromVector, munScalar,
-  mconstant, mfromList1,
+  mconstant, mfromList1, mtoList1,
 
   -- * Array elements
-  Elt(mshape, mindex, mindexPartial, mscalar, mfromList, mlift, mlift2),
+  Elt(mshape, mindex, mindexPartial, mscalar, mfromList, mtoList, mlift, mlift2),
   Primitive(..),
 
   -- * Inductive natural numbers
diff --git a/src/Data/Array/Nested/Internal.hs b/src/Data/Array/Nested/Internal.hs
index 6f0cfc8..c8a0670 100644
--- a/src/Data/Array/Nested/Internal.hs
+++ b/src/Data/Array/Nested/Internal.hs
@@ -206,6 +206,8 @@ class Elt a where
   -- first.
   mfromList :: forall n sh. KnownShapeX (n : sh) => NonEmpty (Mixed sh a) -> Mixed (n : sh) a
 
+  mtoList :: Mixed (n : sh) a -> [Mixed sh a]
+
   -- | Note: this library makes no particular guarantees about the shapes of
   -- arrays "inside" an empty array. With 'mlift' and 'mlift2' you can see the
   -- full 'XArray' and as such you can distinguish different empty arrays by
@@ -260,7 +262,8 @@ instance Storable a => Elt (Primitive a) where
   mindex (M_Primitive a) i = Primitive (X.index a i)
   mindexPartial (M_Primitive a) i = M_Primitive (X.indexPartial a i)
   mscalar (Primitive x) = M_Primitive (X.scalar x)
-  mfromList l = M_Primitive (X.fromList knownShapeX [x | M_Primitive x <- toList l])
+  mfromList l = M_Primitive (X.fromList knownShapeX (coerce (toList l)))
+  mtoList (M_Primitive arr) = coerce (X.toList arr)
 
   mlift :: forall sh1 sh2.
            (Proxy '[] -> XArray (sh1 ++ '[]) a -> XArray (sh2 ++ '[]) a)
@@ -311,6 +314,7 @@ instance (Elt a, Elt b) => Elt (a, b) where
   mscalar (x, y) = M_Tup2 (mscalar x) (mscalar y)
   mfromList l = M_Tup2 (mfromList ((\(M_Tup2 x _) -> x) <$> l))
                        (mfromList ((\(M_Tup2 _ y) -> y) <$> l))
+  mtoList (M_Tup2 a b) = zipWith M_Tup2 (mtoList a) (mtoList b)
   mlift f (M_Tup2 a b) = M_Tup2 (mlift f a) (mlift f b)
   mlift2 f (M_Tup2 a b) (M_Tup2 x y) = M_Tup2 (mlift2 f a x) (mlift2 f b y)
 
@@ -348,13 +352,15 @@ instance (Elt a, KnownShapeX sh') => Elt (Mixed sh' a) where
     | Refl <- X.lemAppAssoc (Proxy @sh1) (Proxy @sh2) (Proxy @sh')
     = M_Nest (mindexPartial @a @sh1 @(sh2 ++ sh') arr i)
 
-  mscalar x = M_Nest x
+  mscalar = M_Nest
 
   mfromList :: forall n sh. KnownShapeX (n : sh)
             => NonEmpty (Mixed sh (Mixed sh' a)) -> Mixed (n : sh) (Mixed sh' a)
   mfromList l
     | Dict <- X.lemKnownShapeX (X.ssxAppend (knownShapeX @(n : sh)) (knownShapeX @sh'))
-    = M_Nest (mfromList ((\(M_Nest x) -> x) <$> l))
+    = M_Nest (mfromList (coerce l))
+
+  mtoList (M_Nest arr) = coerce (mtoList arr)
 
   mlift :: forall sh1 sh2. KnownShapeX sh2
         => (forall shT b. (KnownShapeX shT, Storable b) => Proxy shT -> XArray (sh1 ++ shT) b -> XArray (sh2 ++ shT) b)
@@ -492,6 +498,9 @@ mfromVector sh v
 mfromList1 :: (KnownShapeX '[n], Elt a) => NonEmpty a -> Mixed '[n] a
 mfromList1 = mfromList . fmap mscalar
 
+mtoList1 :: Elt a => Mixed '[n] a -> [a]
+mtoList1 = map munScalar . mtoList
+
 munScalar :: Elt a => Mixed '[] a -> a
 munScalar arr = mindex arr IZX
 
@@ -594,7 +603,11 @@ instance (Elt a, KnownINat n) => Elt (Ranked n a) where
             => NonEmpty (Mixed sh (Ranked n a)) -> Mixed (m : sh) (Ranked n a)
   mfromList l
     | Dict <- lemKnownReplicate (Proxy @n)
-    = M_Ranked (mfromList ((\(M_Ranked x) -> x) <$> l))
+    = M_Ranked (mfromList (coerce l))
+
+  mtoList (M_Ranked arr)
+    | Dict <- lemKnownReplicate (Proxy @n)
+    = coerce (mtoList arr)
 
   mlift :: forall sh1 sh2. KnownShapeX sh2
         => (forall sh' b. (KnownShapeX sh', Storable b) => Proxy sh' -> XArray (sh1 ++ sh') b -> XArray (sh2 ++ sh') b)
@@ -718,7 +731,11 @@ instance (Elt a, KnownShape sh) => Elt (Shaped sh a) where
             => NonEmpty (Mixed sh' (Shaped sh a)) -> Mixed (n : sh') (Shaped sh a)
   mfromList l
     | Dict <- lemKnownMapJust (Proxy @sh)
-    = M_Shaped (mfromList ((\(M_Shaped x) -> x) <$> l))
+    = M_Shaped (mfromList (coerce l))
+
+  mtoList (M_Shaped arr)
+    | Dict <- lemKnownMapJust (Proxy @sh)
+    = coerce (mtoList arr)
 
   mlift :: forall sh1 sh2. KnownShapeX sh2
         => (forall sh' b. (KnownShapeX sh', Storable b) => Proxy sh' -> XArray (sh1 ++ sh') b -> XArray (sh2 ++ sh') b)
@@ -924,6 +941,12 @@ rfromVector sh v
 rfromList1 :: Elt a => NonEmpty a -> Ranked I1 a
 rfromList1 = Ranked . mfromList . fmap mscalar
 
+rtoList :: Elt a => Ranked (S n) a -> [Ranked n a]
+rtoList (Ranked arr) = coerce (mtoList arr)
+
+rtoList1 :: Elt a => Ranked I1 a -> [a]
+rtoList1 = map runScalar . rtoList
+
 runScalar :: Elt a => Ranked I0 a -> a
 runScalar arr = rindex arr IZR
 
@@ -1060,6 +1083,12 @@ sfromVector v
 sfromList1 :: (KnownNat n, Elt a) => NonEmpty a -> Shaped '[n] a
 sfromList1 = Shaped . mfromList . fmap mscalar
 
+stoList :: Elt a => Shaped (n : sh) a -> [Shaped sh a]
+stoList (Shaped arr) = coerce (mtoList arr)
+
+stoList1 :: Elt a => Shaped '[n] a -> [a]
+stoList1 = map sunScalar . stoList
+
 sunScalar :: Elt a => Shaped '[] a -> a
 sunScalar arr = sindex arr IZS