Merge pull request #190 from monkeygroover/rotate-performance

Don't rotate lazily

lib/commands/list_commands.ex

@@ -326,19 +326,19 @@ defmodule Commands.ListCommands do
     def rotate(value, shift) when shift == 0, do: value
     def rotate(value, shift) when not Functions.is_iterable(value), do: Enum.join(rotate(String.graphemes(to_string(value)), shift), "")
     def rotate(value, shift) when shift > 0 do
-        case length(Enum.to_list value) do
+        case Enum.count value do
             0 -> []
             x -> 
                 shift = rem(shift, x)
-                Stream.concat(value |> Stream.drop(shift), value |> Stream.take(shift)) |> Stream.map(fn x -> x end)
+                Stream.concat(value |> Stream.drop(shift), value |> Stream.take(shift)) |> Enum.to_list
         end
     end
     def rotate(value, shift) when shift < 0 do
-        case length(Enum.to_list value) do
+        case Enum.count value do
             0 -> []
             x ->
                 shift = rem(shift, x)
-                Stream.concat(value |> Stream.take(shift), value |> Stream.drop(shift)) |> Stream.map(fn x -> x end)
+                Stream.concat(value |> Stream.take(shift), value |> Stream.drop(shift)) |> Enum.to_list
         end
     end
 

test/commands/special_test.exs

@@ -285,4 +285,8 @@ defmodule SpecialOpsTest do
         assert evaluate("\"abcdef\" 1101S ÅÏu}") == "ABcDef"
         assert evaluate("∞ 10Þ ÅÏ5+} 10£") == [6, 2, 8, 4, 10, 6, 12, 8, 14, 10]
     end
+
+    test "performance of repeated rotation" do
+        assert evaluate("123456789S256FÀ") == ["5", "6", "7", "8", "9", "1", "2", "3", "4"]
+    end
 end