3fb4ea1 · elk · git.iko.soy

git.iko.soy/elk

Fix bug in which foldl and foldr were swapped!

commit3fb4ea1a1afafb27be615975ad2b49f09723d38f authorEvan Czaplicki <info@elm-lang.org> dateWed 16 Apr 2014, 16:27 (13 years ago) parent1edc02f

3 files changed+6−6

compare with master

unifiedsplit

libraries/Array.elm+2−2 libraries/Native/Array.js+2−2 tests/elm/Test/Array.elm+2−2

libraries/Array.elm+2−2

@@ -82,14 +82,14 @@ map = Native.Array.map

8282indexedMap : (Int -> a -> b) -> Array a -> Array b

8383indexedMap = Native.Array.indexedMap

8484

85−{-| Reduce an array from the left.

85+{-| Reduce an array from the left. Read `foldl` as “fold from the left”.

8686

8787 foldl (::) [] (fromList [1,2,3]) == [3,2,1]

8888-}

8989foldl : (a -> b -> b) -> b -> Array a -> b

9090foldl = Native.Array.foldl

9191

92−{-| Reduce an array from the right.

92+{-| Reduce an array from the right. Read `foldr` as “fold from the right”.

9393

9494 foldr (+) 0 (repeat 3 5) == 15

9595-}

libraries/Native/Array.js+2−2

@@ -242,14 +242,14 @@ Elm.Native.Array.make = function(elm) {

242242 }

243243

244244 function foldl(f, b, a) {

245− for (var i = a.table.length - 1; i >= 0; i--) {

245+ for (var i = 0; i < a.table.length; i++) {

246246 b = A2(f, a.height == 0 ? a.table[i] : foldl(f, b, a.table[i]), b);

247247 }

248248 return b;

249249 }

250250

251251 function foldr(f, b, a) {

252− for (var i = 0; i < a.table.length; i++) {

252+ for (var i = a.table.length; i--; ) {

253253 b = A2(f, a.height == 0 ? a.table[i] : foldr(f, b, a.table[i]), b);

254254 }

255255 return b;

tests/elm/Test/Array.elm+2−2

@@ -40,8 +40,8 @@ tests =

4040 ]

4141 mappingAndFoldingTests = [ test "map" <| assertEqual (Array.map sqrt (Array.fromList [1,4,9])) (Array.fromList [1,2,3])

4242 , test "indexedMap" <| assertEqual (Array.indexedMap (*) (Array.fromList [5,5,5])) (Array.fromList [0,5,10])

43− , test "foldl" <| assertEqual (Array.foldl (::) [] (Array.fromList [1,2,3])) [1,2,3]

43+ , test "foldl" <| assertEqual (Array.foldl (::) [] (Array.fromList [1,2,3])) [3,2,1]

4444 , test "foldr" <| assertEqual (Array.foldr (+) 0 (Array.repeat 3 5)) 15

45− , test "foldl 2" <| assertEqual (Array.foldr (::) [] (Array.fromList [1,2,3])) [3,2,1]

45+ , test "foldr 2" <| assertEqual (Array.foldr (::) [] (Array.fromList [1,2,3])) [1,2,3]

4646 ]

4747 in List.concat [creationTests, basicsTests, getAndSetTests, takingArraysApartTests, mappingAndFoldingTests]