blas: make dotAll polymorphic via AFResult (#72)

Changes dotAll from a hardcoded Complex Double return to Scalar a,
consistent with sumAll, productAll, and the rest of the *All family.
Real arrays now return a plain scalar rather than forcing callers to
unwrap an imaginary component that is always zero.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: dmjio

src/ArrayFire/BLAS.hs

@@ -1,5 +1,6 @@
 --------------------------------------------------------------------------------
 {-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeApplications    #-}
 {-# LANGUAGE ViewPatterns        #-}
 --------------------------------------------------------------------------------
 -- |
@@ -113,9 +114,9 @@ dot arr1 arr2 prop1 prop2 =
 -- | Scalar dot product between two vectors. Also referred to as the inner product. Returns the result as a host scalar.
 --
 -- >>> dotAll (vector @Double 10 [1..]) (vector @Double 10 [1..]) None None
--- 385.0 :+ 0.0
+-- 385.0
 dotAll
-  :: AFType a
+  :: forall a . AFResult a
   => Array a
   -- ^ Left-hand side array
   -> Array a
@@ -124,13 +125,12 @@ dotAll
   -- ^ Options for left-hand side. Currently only AF_MAT_NONE and AF_MAT_CONJ are supported.
   -> MatProp
   -- ^ Options for right-hand side. Currently only AF_MAT_NONE and AF_MAT_CONJ are supported.
-  -> Complex Double
-  -- ^ Real and imaginary component result
-dotAll arr1 arr2 prop1 prop2 = do
-  let (real,imag) =
-        infoFromArray22 arr1 arr2 $ \a b c d ->
-          af_dot_all a b c d (toMatProp prop1) (toMatProp prop2)
-  real :+ imag
+  -> Scalar a
+  -- ^ Result as the array's element type
+dotAll arr1 arr2 prop1 prop2 =
+  toAFResult @a $
+    infoFromArray22 arr1 arr2 $ \a b c d ->
+      af_dot_all a b c d (toMatProp prop1) (toMatProp prop2)
 
 -- | Transposes a matrix.
 --

test/ArrayFire/BLASSpec.hs

@@ -40,9 +40,9 @@ spec =
     it "Should dot product two vectors" $ do
       dot (vector @Double 2 (repeat 2)) (vector @Double 2 (repeat 2)) None None
         `shouldBe` scalar @Double 8
-    it "Should produce scalar dot product between two vectors as a Complex number" $ do
+    it "Should produce scalar dot product between two vectors" $ do
       dotAll (vector @Double 2 (repeat 2)) (vector @Double 2 (repeat 2)) None None
-        `shouldBe` 8.0 :+ 0.0
+        `shouldBe` (8.0 :: Double)
     it "Should take the transpose of a matrix" $ do
       transpose (matrix @Double (2,2) [[1,1],[2,2]]) False
         `shouldBe` matrix @Double (2,2) [[1,2],[1,2]]