2 files changed, 39 insertions, 7 deletions
diff --git a/src/Data/Array/Nested.hs b/src/Data/Array/Nested.hs
index 23d20eb..cd2dde7 100644
--- a/src/Data/Array/Nested.hs
+++ b/src/Data/Array/Nested.hs
@@ -4,7 +4,8 @@ module Data.Array.Nested (
   Ranked,
   IxR(..),
   rshape, rindex, rindexPartial, rgenerate, rsumOuter1,
-  rtranspose, rappend, rscalar, rfromVector,
+  rtranspose, rappend, rscalar, rfromVector, runScalar,
+  rconstant,
   -- ** Lifting orthotope operations to 'Ranked' arrays
   rlift,
 
@@ -13,7 +14,8 @@ module Data.Array.Nested (
   IxS(..),
   KnownShape(..), SShape(..),
   sshape, sindex, sindexPartial, sgenerate, ssumOuter1,
-  stranspose, sappend, sscalar, sfromVector,
+  stranspose, sappend, sscalar, sfromVector, sunScalar,
+  sconstant,
   -- ** Lifting orthotope operations to 'Shaped' arrays
   slift,
 
@@ -21,7 +23,8 @@ module Data.Array.Nested (
   Mixed,
   IxX(..),
   KnownShapeX(..), StaticShapeX(..),
-  mgenerate, mtranspose, mappend, mfromVector,
+  mgenerate, mtranspose, mappend, mfromVector, munScalar,
+  mconstant,
 
   -- * Array elements
   Elt(mshape, mindex, mindexPartial, mscalar, mlift, mlift2),
diff --git a/src/Data/Array/Nested/Internal.hs b/src/Data/Array/Nested/Internal.hs
index c85b1fc..4764165 100644
--- a/src/Data/Array/Nested/Internal.hs
+++ b/src/Data/Array/Nested/Internal.hs
@@ -377,6 +377,17 @@ mfromVector sh v
   | otherwise =
       M_Primitive (X.fromVector sh v)
 
+munScalar :: Elt a => Mixed '[] a -> a
+munScalar arr = mindex arr IZX
+
+mconstant :: forall sh a. (KnownShapeX sh, Storable a, Coercible (Mixed sh (Primitive a)) (Mixed sh a))
+          => IxX sh -> a -> Mixed sh a
+mconstant sh x
+  | not (checkBounds sh (knownShapeX @sh)) =
+      error $ "mconstant: Shape " ++ show sh ++ " not valid for shape type " ++ show (knownShapeX @sh)
+  | otherwise =
+      coerce (M_Primitive (X.constant sh x))
+
 mliftPrim :: (KnownShapeX sh, Storable a)
           => (a -> a)
           -> Mixed sh (Primitive a) -> Mixed sh (Primitive a)
@@ -399,7 +410,7 @@ instance (KnownShapeX sh, Storable a, Num a) => Num (Mixed sh (Primitive a)) whe
     case X.ssxToShape' (knownShapeX @sh) of
       Just sh -> M_Primitive (X.constant sh (fromInteger n))
       Nothing -> error "Data.Array.Nested.fromIntegral: \
-                       \Unknown components in shape, use explicit replicate"
+                       \Unknown components in shape, use explicit mconstant"
 
 deriving via Mixed sh (Primitive Int) instance KnownShapeX sh => Num (Mixed sh Int)
 deriving via Mixed sh (Primitive Double) instance KnownShapeX sh => Num (Mixed sh Double)
@@ -732,6 +743,15 @@ rfromVector sh v
   | Dict <- lemKnownReplicate (Proxy @n)
   = Ranked (mfromVector (ixCvtRX sh) v)
 
+runScalar :: Elt a => Ranked I0 a -> a
+runScalar arr = rindex arr IZR
+
+rconstant :: forall n a. (KnownINat n, Storable a, Coercible (Mixed (Replicate n Nothing) (Primitive a)) (Mixed (Replicate n Nothing) a))
+          => IxR n -> a -> Ranked n a
+rconstant sh x
+  | Dict <- lemKnownReplicate (Proxy @n)
+  = Ranked (mconstant (ixCvtRX sh) x)
+
 
 -- ====== API OF SHAPED ARRAYS ====== --
 
@@ -795,10 +815,10 @@ sindexPartial (Shaped arr) idx =
             (rewriteMixed (lemMapJustPlusApp (Proxy @sh1) (Proxy @sh2)) arr)
             (ixCvtSX idx))
 
-sgenerate :: forall sh a. (KnownShape sh, Elt a) => IxS sh -> (IxS sh -> a) -> Shaped sh a
-sgenerate sh f
+sgenerate :: forall sh a. (KnownShape sh, Elt a) => (IxS sh -> a) -> Shaped sh a
+sgenerate f
   | Dict <- lemKnownMapJust (Proxy @sh)
-  = Shaped (mgenerate (ixCvtSX sh) (f . ixCvtXS (knownShape @sh)))
+  = Shaped (mgenerate (ixCvtSX (cvtSShapeIxS (knownShape @sh))) (f . ixCvtXS (knownShape @sh)))
 
 slift :: forall sh1 sh2 a. (KnownShape sh2, Elt a)
       => (forall sh' b. KnownShapeX sh' => Proxy sh' -> XArray (MapJust sh1 ++ sh') b -> XArray (MapJust sh2 ++ sh') b)
@@ -834,3 +854,12 @@ sfromVector :: forall sh a. (KnownShape sh, Storable a) => VS.Vector a -> Shaped
 sfromVector v
   | Dict <- lemKnownMapJust (Proxy @sh)
   = Shaped (mfromVector (ixCvtSX (cvtSShapeIxS (knownShape @sh))) v)
+
+sunScalar :: Elt a => Shaped '[] a -> a
+sunScalar arr = sindex arr IZS
+
+sconstant :: forall sh a. (KnownShape sh, Storable a, Coercible (Mixed (MapJust sh) (Primitive a)) (Mixed (MapJust sh) a))
+          => a -> Shaped sh a
+sconstant x
+  | Dict <- lemKnownMapJust (Proxy @sh)
+  = Shaped (mconstant (ixCvtSX (cvtSShapeIxS (knownShape @sh))) x)