foldMap, foldMap' for PrimArray

Data/Primitive/PrimArray.hs

@@ -66,6 +66,10 @@ module Data.Primitive.PrimArray
   , foldlPrimArray
   , foldlPrimArray'
   , foldlPrimArrayM'
+  , foldrMapPrimArray
+  , foldlMapPrimArray
+  , foldrMapPrimArray'
+  , foldlMapPrimArray'
     -- * Effectful Folding
   , traversePrimArray_
   , itraversePrimArray_
@@ -467,6 +471,32 @@ sizeofPrimArray :: forall a. Prim a => PrimArray a -> Int
 {-# INLINE sizeofPrimArray #-}
 sizeofPrimArray (PrimArray arr#) = I# (quotInt# (sizeofByteArray# arr#) (sizeOf# (undefined :: a)))
 
+-- | Map each element of the primitive array to a monoid, and combine the results.
+--   The combination is right-associated, and the accumulation is lazy.
+foldrMapPrimArray :: forall a m. (Prim a, Monoid m) => (a -> m) -> PrimArray a -> m
+{-# INLINE foldrMapPrimArray #-}
+foldrMapPrimArray f = foldrPrimArray (\a acc -> f a `mappend` acc) mempty
+
+-- | Map each element of the primitive array to a monoid, and combine the results.
+--   The combination is left-associated, and the accumulation is lazy.
+foldlMapPrimArray :: forall a m. (Prim a, Monoid m) => (a -> m) -> PrimArray a -> m
+{-# INLINE foldlMapPrimArray #-}
+foldlMapPrimArray f = foldlPrimArray (\acc a -> acc `mappend` f a) mempty
+
+-- | Map each element of the primitive array to a monoid, and combine the results.
+--   The combination is right-associated, and the accumulation is strict, though
+--   this function is not necessarily strict in its result.
+foldrMapPrimArray' :: forall a m. (Prim a, Monoid m) => (a -> m) -> PrimArray a -> m
+{-# INLINE foldrMapPrimArray' #-}
+foldrMapPrimArray' f = foldrPrimArray (\a !acc -> f a `mappend` acc) mempty
+
+-- | Map each element of the primitive array to a monoid, and combine the results.
+--   The combination is left-associated, and the accumulation is strict, though
+--   this function is not necessarily strict in its result.
+foldlMapPrimArray' :: forall a m. (Prim a, Monoid m) => (a -> m) -> PrimArray a -> m
+{-# INLINE foldlMapPrimArray' #-}
+foldlMapPrimArray' f = foldlPrimArray (\ !acc a -> acc `mappend` f a) mempty
+
 -- | Lazy right-associated fold over the elements of a 'PrimArray'.
 {-# INLINE foldrPrimArray #-}
 foldrPrimArray :: forall a b. Prim a => (a -> b -> b) -> b -> PrimArray a -> b

changelog.md

@@ -29,7 +29,9 @@
 
 ## Changes in version 0.6.4.1
 
- * Add instances for the following newtypes from `base`:
+ * Add `foldMapPrimArray` and `foldMapPrimArray'`
+
+ * Add `Prim` instances for the following newtypes from `base`:
    `Const`, `Identity`, `Down`, `Dual`, `Sum`, `Product`,
    `First`, `Last`, `Min`, `Max`
 

test/primitive-tests.cabal

@@ -38,7 +38,7 @@ test-suite test
                , tasty-quickcheck
                , tagged
                , transformers >= 0.3
-               , quickcheck-classes >= 0.4.11.1
+               , quickcheck-classes >= 0.4.14.2
   ghc-options: -O2
 
 source-repository head