From be474de1def8aa2c1057340c7e1ad614718390e5 Mon Sep 17 00:00:00 2001
From: William Rusnack <williamrusnack@gmail.com>
Date: Fri, 12 Jul 2024 13:55:14 -0400
Subject: [PATCH] added filterWithKey to IsMap

---
 mono-traversable/ChangeLog.md           |  5 +++++
 mono-traversable/package.yaml           |  2 +-
 mono-traversable/src/Data/Containers.hs | 16 ++++++++++++++--
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/mono-traversable/ChangeLog.md b/mono-traversable/ChangeLog.md
index 4f0b449d..291498c7 100644
--- a/mono-traversable/ChangeLog.md
+++ b/mono-traversable/ChangeLog.md
@@ -1,5 +1,10 @@
 # ChangeLog for mono-traversable
 
+## 1.0.19.0
+
+* Added `filterWithKey` to class `IsMap`
+  [#231](https://github.com/snoyberg/mono-traversable/pull/231)
+
 ## 1.0.18.0
 
 * Added MonoPointed instance for text Builder
diff --git a/mono-traversable/package.yaml b/mono-traversable/package.yaml
index d8a68e4f..0bae5d63 100644
--- a/mono-traversable/package.yaml
+++ b/mono-traversable/package.yaml
@@ -1,5 +1,5 @@
 name:        mono-traversable
-version:     1.0.18.0
+version:     1.0.19.0
 synopsis:    Type classes for mapping, folding, and traversing monomorphic containers
 description: Please see the README at <https://www.stackage.org/package/mono-traversable>
 category:    Data
diff --git a/mono-traversable/src/Data/Containers.hs b/mono-traversable/src/Data/Containers.hs
index 31322e8a..04ad1f75 100644
--- a/mono-traversable/src/Data/Containers.hs
+++ b/mono-traversable/src/Data/Containers.hs
@@ -548,8 +548,14 @@ class (MonoTraversable map, SetContainer map) => IsMap map where
     -- | Filter values in a map.
     --
     -- @since 1.0.9.0
-    filterMap :: IsMap map => (MapValue map -> Bool) -> map -> map
-    filterMap p = mapFromList . filter (p . snd) . mapToList
+    filterMap :: (MapValue map -> Bool) -> map -> map
+    filterMap = filterWithKey . const
+
+    -- | Filter a map with keys and values.
+    --
+    -- @since 1.0.19.0
+    filterWithKey :: (ContainerKey map -> MapValue map -> Bool) -> map -> map
+    filterWithKey p = mapFromList . filter (uncurry p) . mapToList
 
 -- | This instance uses the functions from "Data.Map.Strict".
 instance Ord key => IsMap (Map.Map key value) where
@@ -599,6 +605,8 @@ instance Ord key => IsMap (Map.Map key value) where
     {-# INLINE omapKeysWith #-}
     filterMap = Map.filter
     {-# INLINE filterMap #-}
+    filterWithKey = Map.filterWithKey
+    {-# INLINE filterWithKey #-}
 
 -- | This instance uses the functions from "Data.HashMap.Strict".
 instance (Eq key, Hashable key) => IsMap (HashMap.HashMap key value) where
@@ -636,6 +644,8 @@ instance (Eq key, Hashable key) => IsMap (HashMap.HashMap key value) where
     --mapKeysWith = HashMap.mapKeysWith
     filterMap = HashMap.filter
     {-# INLINE filterMap #-}
+    filterWithKey = HashMap.filterWithKey
+    {-# INLINE filterWithKey #-}
 
 -- | This instance uses the functions from "Data.IntMap.Strict".
 instance IsMap (IntMap.IntMap value) where
@@ -684,6 +694,8 @@ instance IsMap (IntMap.IntMap value) where
     {-# INLINE omapKeysWith #-}
     filterMap = IntMap.filter
     {-# INLINE filterMap #-}
+    filterWithKey = IntMap.filterWithKey
+    {-# INLINE filterWithKey #-}
 
 instance Eq key => IsMap [(key, value)] where
     type MapValue [(key, value)] = value