Merge pull request #151 from cryogenian/with-index

added FunctorWithIndex, FoldableWithIndex, TraversableWithIndex insta…

src/Data/List/Lazy/Types.purs

@@ -12,16 +12,16 @@ import Control.MonadZero (class MonadZero)
 import Control.Plus (class Plus)
 import Data.Eq (class Eq1, eq1)
 import Data.Foldable (class Foldable, foldMap, foldl, foldr)
-import Data.FoldableWithIndex (class FoldableWithIndex, foldlWithIndex, foldrWithIndex)
-import Data.FunctorWithIndex (class FunctorWithIndex)
+import Data.FoldableWithIndex (class FoldableWithIndex, foldlWithIndex, foldrWithIndex, foldMapWithIndex)
+import Data.FunctorWithIndex (class FunctorWithIndex, mapWithIndex)
 import Data.Lazy (Lazy, defer, force)
-import Data.Maybe (Maybe(..))
+import Data.Maybe (Maybe(..), maybe)
 import Data.Newtype (class Newtype, unwrap)
 import Data.NonEmpty (NonEmpty, (:|))
 import Data.NonEmpty as NE
 import Data.Ord (class Ord1, compare1)
 import Data.Traversable (class Traversable, traverse, sequence)
-import Data.TraversableWithIndex (class TraversableWithIndex)
+import Data.TraversableWithIndex (class TraversableWithIndex, traverseWithIndex)
 import Data.Tuple (Tuple(..), snd)
 import Data.Unfoldable (class Unfoldable)
 import Data.Unfoldable1 (class Unfoldable1)
@@ -269,3 +269,15 @@ instance traversableNonEmptyList :: Traversable NonEmptyList where
     map (\xxs -> NonEmptyList $ defer \_ -> xxs) $ traverse f (force nel)
   sequence (NonEmptyList nel) =
     map (\xxs -> NonEmptyList $ defer \_ -> xxs) $ sequence (force nel)
+
+instance functorWithIndexNonEmptyList :: FunctorWithIndex Int NonEmptyList where
+  mapWithIndex f (NonEmptyList ne) = NonEmptyList $ defer \_ -> mapWithIndex (f <<< maybe 0 (add 1)) $ force ne
+
+instance foldableWithIndexNonEmptyList :: FoldableWithIndex Int NonEmptyList where
+  foldMapWithIndex f (NonEmptyList ne) = foldMapWithIndex (f <<< maybe 0 (add 1)) $ force ne
+  foldlWithIndex f b (NonEmptyList ne) = foldlWithIndex (f <<< maybe 0 (add 1)) b $ force ne
+  foldrWithIndex f b (NonEmptyList ne) = foldrWithIndex (f <<< maybe 0 (add 1)) b $ force ne
+
+instance traversableWithIndexNonEmptyList :: TraversableWithIndex Int NonEmptyList where
+  traverseWithIndex f (NonEmptyList ne) =
+    map (\xxs -> NonEmptyList $ defer \_ -> xxs) $ traverseWithIndex (f <<< maybe 0 (add 1)) $ force ne

src/Data/List/NonEmpty.purs

@@ -59,6 +59,7 @@ module Data.List.NonEmpty
 import Prelude
 
 import Data.Foldable (class Foldable)
+import Data.FunctorWithIndex (mapWithIndex) as FWI
 import Data.List ((:))
 import Data.List as L
 import Data.List.Types (NonEmptyList(..))
@@ -219,8 +220,11 @@ appendFoldable :: forall t a. Foldable t => NonEmptyList a -> t a -> NonEmptyLis
 appendFoldable (NonEmptyList (x :| xs)) ys =
   NonEmptyList (x :| (xs <> L.fromFoldable ys))
 
+-- | Apply a function to each element and its index in a list starting at 0.
+-- |
+-- | Deprecated. Use Data.FunctorWithIndex instead.
 mapWithIndex :: forall a b. (Int -> a -> b) -> NonEmptyList a -> NonEmptyList b
-mapWithIndex = wrappedOperation "mapWithIndex" <<< L.mapWithIndex
+mapWithIndex = FWI.mapWithIndex
 
 sort :: forall a. Ord a => NonEmptyList a -> NonEmptyList a
 sort xs = sortBy compare xs

src/Data/List/Types.purs

@@ -12,17 +12,17 @@ import Control.MonadZero (class MonadZero)
 import Control.Plus (class Plus)
 import Data.Eq (class Eq1, eq1)
 import Data.Foldable (class Foldable, foldl, foldr, intercalate)
-import Data.FoldableWithIndex (class FoldableWithIndex, foldlWithIndex, foldrWithIndex)
-import Data.FunctorWithIndex (class FunctorWithIndex)
-import Data.Maybe (Maybe(..))
+import Data.FoldableWithIndex (class FoldableWithIndex, foldlWithIndex, foldrWithIndex, foldMapWithIndex)
+import Data.FunctorWithIndex (class FunctorWithIndex, mapWithIndex)
+import Data.Maybe (Maybe(..), maybe)
 import Data.Newtype (class Newtype)
 import Data.NonEmpty (NonEmpty, (:|))
 import Data.NonEmpty as NE
 import Data.Ord (class Ord1, compare1)
 import Data.Semigroup.Foldable (class Foldable1)
 import Data.Semigroup.Traversable (class Traversable1, traverse1)
 import Data.Traversable (class Traversable, traverse)
-import Data.TraversableWithIndex (class TraversableWithIndex)
+import Data.TraversableWithIndex (class TraversableWithIndex, traverseWithIndex)
 import Data.Tuple (Tuple(..), snd)
 import Data.Unfoldable (class Unfoldable)
 import Data.Unfoldable1 (class Unfoldable1)
@@ -213,6 +213,17 @@ derive newtype instance traversableNonEmptyList :: Traversable NonEmptyList
 
 derive newtype instance foldable1NonEmptyList :: Foldable1 NonEmptyList
 
+instance functorWithIndexNonEmptyList :: FunctorWithIndex Int NonEmptyList where
+  mapWithIndex fn (NonEmptyList ne) = NonEmptyList $ mapWithIndex (fn <<< maybe 0 (add 1)) ne
+
+instance foldableWithIndexNonEmptyList :: FoldableWithIndex Int NonEmptyList where
+  foldMapWithIndex f (NonEmptyList ne) = foldMapWithIndex (f <<< maybe 0 (add 1)) ne
+  foldlWithIndex f b (NonEmptyList ne) = foldlWithIndex (f <<< maybe 0 (add 1)) b ne
+  foldrWithIndex f b (NonEmptyList ne) = foldrWithIndex (f <<< maybe 0 (add 1)) b ne
+
+instance traversableWithIndexNonEmptyList :: TraversableWithIndex Int NonEmptyList where
+  traverseWithIndex f (NonEmptyList ne) = NonEmptyList <$> traverseWithIndex (f <<< maybe 0 (add 1)) ne
+
 instance traversable1NonEmptyList :: Traversable1 NonEmptyList where
   traverse1 f (NonEmptyList (a :| as)) =
     foldl (\acc -> lift2 (flip nelCons) acc <<< f) (pure <$> f a) as

test/Test/Data/List.purs

@@ -217,7 +217,7 @@ testList = do
   assert $ catMaybes (l [Nothing, Just 2, Nothing, Just 4]) == l [2, 4]
 
   log "mapWithIndex should take a list of values and apply a function which also takes the index into account"
-  assert $ mapWithIndex (\x ix -> x + ix) (fromFoldable [0, 1, 2, 3]) == fromFoldable [0, 2, 4, 6]
+  assert $ mapWithIndex (\x ix -> x + ix) (l [0, 1, 2, 3]) == l [0, 2, 4, 6]
 
   log "sort should reorder a list into ascending order based on the result of compare"
   assert $ sort (l [1, 3, 2, 5, 6, 4]) == l [1, 2, 3, 4, 5, 6]

test/Test/Data/List/Lazy.purs

@@ -52,31 +52,40 @@ testListLazy = do
 
   log "foldlWithIndex should be correct"
   assert $ foldlWithIndex (\i b _ -> i + b) 0 (range 0 10000) == 50005000
+  assert $ map (foldlWithIndex (\i b _ -> i + b) 0) (NEL.fromFoldable (range 0 10000)) == Just 50005000
 
   log "foldlWithIndex should be stack-safe"
   void $ pure $ foldlWithIndex (\i b _ -> i + b) 0 $ range 0 100000
+  void $ pure $ map (foldlWithIndex (\i b _ -> i + b) 0) $ NEL.fromFoldable $ range 0 100000
 
   log "foldrWithIndex should be correct"
   assert $ foldrWithIndex (\i _ b -> i + b) 0 (range 0 10000) == 50005000
+  assert $ map (foldrWithIndex (\i _ b -> i + b) 0) (NEL.fromFoldable (range 0 10000)) == Just 50005000
 
   log "foldrWithIndex should be stack-safe"
   void $ pure $ foldrWithIndex (\i _ b -> i + b) 0 $ range 0 100000
+  void $ pure $ map (foldrWithIndex (\i _ b -> i + b) 0) $ NEL.fromFoldable $ range 0 100000
 
   log "foldMapWithIndex should be stack-safe"
   void $ pure $ foldMapWithIndex (\i _ -> Additive i) $ range 1 100000
+  void $ pure $ map (foldMapWithIndex (\i _ -> Additive i)) $ NEL.fromFoldable $ range 1 100000
 
   log "foldMapWithIndex should be left-to-right"
   assert $ foldMapWithIndex (\i _ -> show i) (fromFoldable [0, 0, 0]) == "012"
+  assert $ map (foldMapWithIndex (\i _ -> show i)) (NEL.fromFoldable [0, 0, 0]) == Just "012"
 
   log "traverse should be stack-safe"
   assert $ ((traverse Just longList) >>= last) == last longList
 
   log "traverseWithIndex should be stack-safe"
   assert $ traverseWithIndex (const Just) longList == Just longList
+  assert $ traverseWithIndex (const Just) (NEL.fromFoldable longList) == Just (NEL.fromFoldable longList)
 
   log "traverseWithIndex should be correct"
   assert $ traverseWithIndex (\i a -> Just $ i + a) (fromFoldable [2, 2, 2])
            == Just (fromFoldable [2, 3, 4])
+  assert $ map (traverseWithIndex (\i a -> Just $ i + a)) (NEL.fromFoldable [2, 2, 2])
+           == Just (NEL.fromFoldable [2, 3, 4])
 
   log "bind should be stack-safe"
   void $ pure $ last $ longList >>= pure
@@ -257,6 +266,7 @@ testListLazy = do
 
   log "mapWithIndex should take a list of values and apply a function which also takes the index into account"
   assert $ mapWithIndex (\x ix -> x + ix) (fromFoldable [0, 1, 2, 3]) == fromFoldable [0, 2, 4, 6]
+  assert $ map (mapWithIndex (\x ix -> x + ix)) (NEL.fromFoldable [0, 1, 2, 3]) == NEL.fromFoldable [0, 2, 4, 6]
 
   -- log "sort should reorder a list into ascending order based on the result of compare"
   -- assert $ sort (l [1, 3, 2, 5, 6, 4]) == l [1, 2, 3, 4, 5, 6]

test/Test/Data/List/NonEmpty.purs

@@ -5,6 +5,8 @@ import Prelude
 import Effect (Effect)
 import Effect.Console (log)
 import Data.Foldable (class Foldable, foldM, foldMap, foldl, length)
+import Data.FoldableWithIndex (foldlWithIndex, foldrWithIndex, foldMapWithIndex)
+import Data.TraversableWithIndex (traverseWithIndex)
 import Data.List as L
 import Data.List.NonEmpty as NEL
 import Data.Maybe (Maybe(..))
@@ -238,6 +240,31 @@ testNonEmptyList = do
   log "append should be stack-safe"
   void $ pure $ xs <> xs
 
+  log "foldlWithIndex should be correct"
+  assert $ (foldlWithIndex (\i b _ -> i + b) 0 <$> (NEL.fromFoldable (L.range 0 10000))) == Just 50005000
+
+  log "foldlWithIndex should be stack-safe"
+  void $ pure $ map (foldlWithIndex (\i b _ -> i + b) 0) $ NEL.fromFoldable $ L.range 0 100000
+
+  log "foldrWithIndex should be correct"
+  assert $ (foldrWithIndex (\i _ b -> i + b) 0 <$> (NEL.fromFoldable (L.range 0 10000))) == Just 50005000
+
+  log "foldrWithIndex should be stack-safe"
+  void $ pure $ map (foldrWithIndex (\i b _ -> i + b) 0) $ NEL.fromFoldable $ L.range 0 100000
+
+  log "foldMapWithIndex should be stack-safe"
+  void $ pure $ map (foldMapWithIndex (\i _ -> Additive i)) $ NEL.fromFoldable $ L.range 1 100000
+
+  log "foldMapWithIndex should be left-to-right"
+  assert $ map (foldMapWithIndex (\i _ -> show i)) (NEL.fromFoldable [0, 0, 0]) == Just "012"
+
+  log "traverseWithIndex should be stack-safe"
+  assert $ map (traverseWithIndex (const Just)) (NEL.fromFoldable xs) == Just (NEL.fromFoldable xs)
+
+  log "traverseWithIndex should be correct"
+  assert $ map (traverseWithIndex (\i a -> Just $ i + a)) (NEL.fromFoldable [2, 2, 2])
+           == Just (NEL.fromFoldable [2, 3, 4])
+
 odd :: Int -> Boolean
 odd n = n `mod` 2 /= zero