From 76175536c6b00f4bbd12da06436e6a57e12ec1f6 Mon Sep 17 00:00:00 2001
From: Simon Jakobi <simon.jakobi@gmail.com>
Date: Mon, 25 Apr 2022 02:51:35 +0200
Subject: [PATCH] Add comments

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

diff --git a/Data/HashMap/Internal.hs b/Data/HashMap/Internal.hs
index 46dba689..e9346cc6 100644
--- a/Data/HashMap/Internal.hs
+++ b/Data/HashMap/Internal.hs
@@ -2311,8 +2311,9 @@ updateOrConcatWithKey :: Eq k => (k -> v -> v -> (# v #)) -> A.Array (Leaf k v)
 updateOrConcatWithKey f ary1 ary2 = A.run $ do
     let n1 = A.length ary1
     let n2 = A.length ary2
+    -- initialize output array with first element of ary1
     mary <- A.new (n1 + n2) (A.index ary1 0)
-    -- copy over all elements from ary1
+    -- copy over remaining elements from ary1
     A.copy ary1 1 mary 1 (n1-1)
     -- append or update all elements from ary2
     let go !iEnd !i2 !iMut