From 282fa4abbf4d80a50249f361f0e1f31347c114ed Mon Sep 17 00:00:00 2001
From: Pomin Wu <pomin5@protonmail.com>
Date: Thu, 6 Jan 2022 06:52:55 +0800
Subject: [PATCH] Add Map.filterMap & fixed #151

---
 native/src/TableclothMap.ml    |  5 +++++
 native/src/TableclothMap.mli   | 14 ++++++++++++--
 rescript/src/TableclothMap.ml  |  7 +++++++
 rescript/src/TableclothMap.mli | 14 ++++++++++++--
 4 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/native/src/TableclothMap.ml b/native/src/TableclothMap.ml
index 271fbd7b..3459f071 100644
--- a/native/src/TableclothMap.ml
+++ b/native/src/TableclothMap.ml
@@ -94,6 +94,11 @@ let map_with_index = mapWithIndex
 
 let filter = Base.Map.filter
 
+let filterMap m ~f =
+  Base.Map.filter_mapi m ~f:(fun ~key ~data -> f ~key ~value:data)
+
+let filter_map = filterMap
+
 let partition m ~f =
   Base.Map.partitioni_tf m ~f:(fun ~key ~data -> f ~key ~value:data)
 
diff --git a/native/src/TableclothMap.mli b/native/src/TableclothMap.mli
index 62d08fe8..e643560a 100644
--- a/native/src/TableclothMap.mli
+++ b/native/src/TableclothMap.mli
@@ -18,12 +18,12 @@
         end)
       end
 
-      type animal = 
+      type animal =
         | Cow
         | Pig
         | Alpacca
 
-      let pointToAnimal : animal Map.Of(Point).t = 
+      let pointToAnimal : animal Map.Of(Point).t =
         Map.fromList (module Points) [((0, 0), Alpacca); ((3, 4), Cow); ((6, 7), Sheep)]
     ]}
 
@@ -409,6 +409,16 @@ val filter :
     ]}
 *)
 
+val filterMap :
+     ('key, 'value, 'id) t
+  -> f:(key:'key -> value:'value -> 'value option)
+  -> ('key, 'value, 'id) t
+
+val filter_map :
+     ('key, 'value, 'id) t
+  -> f:(key:'key -> value:'value -> 'value option)
+  -> ('key, 'value, 'id) t
+
 val partition :
      ('key, 'value, 'id) t
   -> f:(key:'key -> value:'value -> bool)
diff --git a/rescript/src/TableclothMap.ml b/rescript/src/TableclothMap.ml
index ae2f2555..6022eb8a 100644
--- a/rescript/src/TableclothMap.ml
+++ b/rescript/src/TableclothMap.ml
@@ -57,6 +57,13 @@ let map_with_index = mapWithIndex
 
 let filter m ~f = Belt.Map.keep m (fun _ value -> f value)
 
+let filterMap m ~f =
+  Belt.Map.mapWithKey m (fun key value -> f ~key ~value)
+  |> fun m -> Belt.Map.keep m (fun _ value -> Belt.Option.isSome value)
+  |> fun m -> Belt.Map.map m Belt.Option.getExn
+
+let filter_map = filterMap
+
 let partition m ~f = Belt.Map.partition m (fun key value -> f ~key ~value)
 
 let find m ~f = Belt.Map.findFirstBy m (fun key value -> f ~key ~value)
diff --git a/rescript/src/TableclothMap.mli b/rescript/src/TableclothMap.mli
index c9fb3a83..868d32e6 100644
--- a/rescript/src/TableclothMap.mli
+++ b/rescript/src/TableclothMap.mli
@@ -18,12 +18,12 @@
         end)
       end
 
-      type animal = 
+      type animal =
         | Cow
         | Pig
         | Alpacca
 
-      let pointToAnimal : animal Map.Of(Point).t = 
+      let pointToAnimal : animal Map.Of(Point).t =
         Map.fromList (module Points) [((0, 0), Alpacca); ((3, 4), Cow); ((6, 7), Sheep)]
     ]}
 
@@ -409,6 +409,16 @@ val filter :
     ]}
 *)
 
+val filterMap :
+     ('key, 'value, 'id) t
+  -> f:(key:'key -> value:'value -> 'value option)
+  -> ('key, 'value, 'id) t
+
+val filter_map :
+     ('key, 'value, 'id) t
+  -> f:(key:'key -> value:'value -> 'value option)
+  -> ('key, 'value, 'id) t
+
 val partition :
      ('key, 'value, 'id) t
   -> f:(key:'key -> value:'value -> bool)