Expose IntMap.traverseMaybeWithKey (#743)

Closes #402.

Author: sjakobi

containers/src/Data/IntMap/Internal.hs

@@ -1891,6 +1891,8 @@ traverseMaybeMissing f = WhenMissing
 
 
 -- | /O(n)/. Traverse keys\/values and collect the 'Just' results.
+--
+-- @since UNRELEASED
 traverseMaybeWithKey
   :: Applicative f => (Key -> a -> f (Maybe b)) -> IntMap a -> f (IntMap b)
 traverseMaybeWithKey f = go

containers/src/Data/IntMap/Lazy.hs

@@ -157,6 +157,7 @@ module Data.IntMap.Lazy (
     , IM.map
     , mapWithKey
     , traverseWithKey
+    , traverseMaybeWithKey
     , mapAccum
     , mapAccumWithKey
     , mapAccumRWithKey

containers/src/Data/IntMap/Strict.hs

@@ -176,6 +176,7 @@ module Data.IntMap.Strict (
     , map
     , mapWithKey
     , traverseWithKey
+    , traverseMaybeWithKey
     , mapAccum
     , mapAccumWithKey
     , mapAccumRWithKey

containers/src/Data/IntMap/Strict/Internal.hs

@@ -923,6 +923,8 @@ traverseWithKey f = go
 {-# INLINE traverseWithKey #-}
 
 -- | /O(n)/. Traverse keys\/values and collect the 'Just' results.
+--
+-- @since UNRELEASED
 traverseMaybeWithKey
   :: Applicative f => (Key -> a -> f (Maybe b)) -> IntMap a -> f (IntMap b)
 traverseMaybeWithKey f = go