From e94a09b3ec92c46dbdcd40195e40842830e7472b Mon Sep 17 00:00:00 2001
From: Tissevert <tissevert+devel@marvid.fr>
Date: Tue, 17 Mar 2020 15:25:12 +0100
Subject: [PATCH] Add a Traversable instance for IdMap, needed in reveal and
 useful in general to be able to use atAll

---
 src/Data/Id.hs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/Data/Id.hs b/src/Data/Id.hs
index b96afb0..b79bd33 100644
--- a/src/Data/Id.hs
+++ b/src/Data/Id.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE DeriveTraversable #-}
 {-# LANGUAGE FlexibleContexts #-}
 module Data.Id (
       Id(..)
@@ -34,7 +35,7 @@ newtype Id a = Id {
   } deriving (Eq, Enum, Ord, Show)
 newtype IdMap a b = IdMap {
     intMap :: IntMap b
-  } deriving (Show, Functor, Semigroup, Monoid, Foldable)
+  } deriving (Show, Functor, Semigroup, Monoid, Foldable, Traversable)
 type Indexed a = IdMap a a
 
 at :: IdMap a b -> Id a -> b