match Foldable.foldl1's argument order to DA.List.foldl1's order

compiler/damlc/daml-stdlib-src/DA/Foldable.daml

@@ -50,7 +50,7 @@ class Foldable t where
   foldl1 : (a -> a -> a) -> t a -> a
   foldl1 f xs = O.fromSomeNote "foldl1: empty input" (foldl mf None xs)
     where
-      mf m x = Some (case m of None -> x; Some y -> f x y)
+      mf m x = Some (case m of None -> x; Some y -> f y x)
 
   -- | List of elements of a structure, from left to right.
   toList : t a -> [a]

compiler/damlc/tests/daml-test-files/List.daml

@@ -1,19 +1,20 @@
 -- Copyright (c) 2020, Digital Asset (Switzerland) GmbH and/or its affiliates.
 -- All rights reserved.
 
--- @INFO range=127:17-127:32; Use dedup
--- @INFO range=313:10-313:24; Evaluate
--- @INFO range=328:38-328:48; Use sum
--- @INFO range=329:43-329:53; Use sum
--- @INFO range=330:29-330:39; Use sum
--- @INFO range=333:3-333:23; Use head
--- @INFO range=338:29-338:36; Use head
+-- @INFO range=128:17-128:32; Use dedup
+-- @INFO range=314:10-314:24; Evaluate
+-- @INFO range=335:38-335:48; Use sum
+-- @INFO range=336:43-336:53; Use sum
+-- @INFO range=337:29-337:39; Use sum
+-- @INFO range=340:3-340:23; Use head
+-- @INFO range=345:29-345:36; Use head
 
 module List where
 
 import DA.List
 import DA.Assert
 import DA.Optional
+import qualified DA.Foldable as Foldable
 
 data Foo = Foo with x : Int; y : Text
   deriving (Eq, Show)
@@ -324,6 +325,12 @@ testFoldr1 = scenario do
   "abc" === foldr1 (<>) ["a", "b", "c"]
   2 === foldr1 (-) [1, 2, 3]
 
+testFoldable = scenario do
+  "abc" === Foldable.foldl1 (<>) ["a", "b", "c"]
+  -4 === Foldable.foldl1 (-) [1, 2, 3]
+  "abc" === Foldable.foldr1 (<>) ["a", "b", "c"]
+  2 === Foldable.foldr1 (-) [1, 2, 3]
+
 testRepeatedly = scenario do
   [15, 12, 5] === repeatedly (\x -> (foldl1 (+) x, drop 2 x)) [1..5]
   [10, 22, 34, 10] === repeatedly (\x -> (foldl1 (+) (take 4 x), drop 3 x)) [1..10]