scalar

2 files changed, 18 insertions, 3 deletions

diff --git a/src/Data/Array/Nested.hs b/src/Data/Array/Nested.hs
index 0a9408b..9e4c0e7 100644
--- a/src/Data/Array/Nested.hs
+++ b/src/Data/Array/Nested.hs
@@ -4,7 +4,7 @@ module Data.Array.Nested (
   Ranked,
   IxR(..),
   rshape, rindex, rindexPartial, rgenerate, rsumOuter1,
-  rtranspose,
+  rtranspose, rscalar,
   -- ** Lifting orthotope operations to 'Ranked' arrays
   rlift,
 
@@ -13,7 +13,7 @@ module Data.Array.Nested (
   IxS(..),
   KnownShape(..), SShape(..),
   sshape, sindex, sindexPartial, sgenerate, ssumOuter1,
-  stranspose,
+  stranspose, sscalar,
   -- ** Lifting orthotope operations to 'Shaped' arrays
   slift,
 
@@ -24,7 +24,7 @@ module Data.Array.Nested (
   mgenerate, mtranspose,
 
   -- * Array elements
-  Elt(mshape, mindex, mindexPartial, mlift),
+  Elt(mshape, mindex, mindexPartial, mscalar, mlift),
   Primitive(..),
 
   -- * Inductive natural numbers
diff --git a/src/Data/Array/Nested/Internal.hs b/src/Data/Array/Nested/Internal.hs
index 209d594..1079e99 100644
--- a/src/Data/Array/Nested/Internal.hs
+++ b/src/Data/Array/Nested/Internal.hs
@@ -146,6 +146,7 @@ class Elt a where
   mshape :: KnownShapeX sh => Mixed sh a -> IxX sh
   mindex :: Mixed sh a -> IxX sh -> a
   mindexPartial :: forall sh sh'. Mixed (sh ++ sh') a -> IxX sh -> Mixed sh' a
+  mscalar :: a -> Mixed '[] a
 
   mlift :: forall sh1 sh2. KnownShapeX sh2
         => (forall sh' b. (KnownShapeX sh', Storable b) => Proxy sh' -> XArray (sh1 ++ sh') b -> XArray (sh2 ++ sh') b)
@@ -189,6 +190,7 @@ instance Storable a => Elt (Primitive a) where
   mshape (M_Primitive a) = X.shape a
   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)
 
   mlift :: forall sh1 sh2.
            (Proxy '[] -> XArray (sh1 ++ '[]) a -> XArray (sh2 ++ '[]) a)
@@ -231,6 +233,7 @@ instance (Elt a, Elt b) => Elt (a, b) where
   mshape (M_Tup2 a _) = mshape a
   mindex (M_Tup2 a b) i = (mindex a i, mindex b i)
   mindexPartial (M_Tup2 a b) i = M_Tup2 (mindexPartial a i) (mindexPartial b i)
+  mscalar (x, y) = M_Tup2 (mscalar x) (mscalar y)
   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)
 
@@ -265,6 +268,8 @@ 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
+
   mlift :: forall sh1 sh2. KnownShapeX sh2
         => (forall shT b. (KnownShapeX shT, Storable b) => Proxy shT -> XArray (sh1 ++ shT) b -> XArray (sh2 ++ shT) b)
         -> Mixed sh1 (Mixed sh' a) -> Mixed sh2 (Mixed sh' a)
@@ -444,6 +449,8 @@ instance (KnownINat n, Elt a) => Elt (Ranked n a) where
     = coerce @(Mixed sh' (Mixed (Replicate n Nothing) a)) @(Mixed sh' (Ranked n a)) $
         mindexPartial arr i
 
+  mscalar (Ranked x) = M_Ranked (M_Nest x)
+
   mlift :: forall sh1 sh2. KnownShapeX sh2
         => (forall sh' b. (KnownShapeX sh', Storable b) => Proxy sh' -> XArray (sh1 ++ sh') b -> XArray (sh2 ++ sh') b)
         -> Mixed sh1 (Ranked n a) -> Mixed sh2 (Ranked n a)
@@ -547,6 +554,8 @@ instance (KnownShape sh, Elt a) => Elt (Shaped sh a) where
     = coerce @(Mixed sh2 (Mixed (MapJust sh) a)) @(Mixed sh2 (Shaped sh a)) $
         mindexPartial arr i
 
+  mscalar (Shaped x) = M_Shaped (M_Nest x)
+
   mlift :: forall sh1 sh2. KnownShapeX sh2
         => (forall sh' b. (KnownShapeX sh', Storable b) => Proxy sh' -> XArray (sh1 ++ sh') b -> XArray (sh2 ++ sh') b)
         -> Mixed sh1 (Shaped sh a) -> Mixed sh2 (Shaped sh a)
@@ -707,6 +716,9 @@ rappend :: forall n a. (KnownINat n, Elt a)
         => Ranked (S n) a -> Ranked (S n) a -> Ranked (S n) a
 rappend | Dict <- lemKnownReplicate (Proxy @n) = coerce mappend
 
+rscalar :: Elt a => a -> Ranked I0 a
+rscalar x = Ranked (mscalar x)
+
 
 -- ====== API OF SHAPED ARRAYS ====== --
 
@@ -800,3 +812,6 @@ stranspose perm (Shaped arr)
 sappend :: forall n m sh a. (KnownNat n, KnownNat m, KnownShape sh, Elt a)
         => Shaped (n : sh) a -> Shaped (m : sh) a -> Shaped (n + m : sh) a
 sappend | Dict <- lemKnownMapJust (Proxy @sh) = coerce mappend
+
+sscalar :: Elt a => a -> Shaped '[] a
+sscalar x = Shaped (mscalar x)