Use FunctorWithIndex.mapWithIndex (#233)

* Use FunctorWithIndex.mapWithIndex

* Add changelog entry

Author: JordanMartinez

CHANGELOG.md

@@ -11,6 +11,7 @@ New features:
 Bugfixes:
 
 Other improvements:
+- Use more efficient implementation for `mapWithIndex` (#233 by @JordanMartinez)
 
 ## [v7.1.0](https://github.com/purescript/purescript-arrays/releases/tag/v7.1.0) - 2022-08-06
 

src/Data/Array.purs

@@ -143,6 +143,7 @@ import Data.Array.ST as STA
 import Data.Array.ST.Iterator as STAI
 import Data.Foldable (class Foldable, traverse_)
 import Data.Foldable as F
+import Data.FunctorWithIndex as FWI
 import Data.Maybe (Maybe(..), maybe, isJust, fromJust, isNothing)
 import Data.Traversable (sequence, traverse)
 import Data.Tuple (Tuple(..), fst, snd)
@@ -738,8 +739,7 @@ catMaybes = mapMaybe identity
 -- | ```
 -- |
 mapWithIndex :: forall a b. (Int -> a -> b) -> Array a -> Array b
-mapWithIndex f xs =
-  zipWith f (range 0 (length xs - 1)) xs
+mapWithIndex = FWI.mapWithIndex
 
 -- | Change the elements at the specified indices in index/value pairs.
 -- | Out-of-bounds indices will have no effect.