add left arrow for resetting tape position (related to #72)

For now, we will not go backwards as I believe this would imply that machines can go backwards and forwards. However, having the left arrow reset the tape to the beginning is helpful.
CSchank · Mar 7, 2019 · 7b8ae0f · 7b8ae0f
1 parent 7f3afb8
commit 7b8ae0f
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/src/Simulating.elm b/src/Simulating.elm
@@ -375,6 +375,14 @@ update env msg ( model, pModel, sModel ) =
                     _ ->
                         ( ( model, pModel, sModel ), False, Cmd.none )
 
+            else if k == 37 then
+                --left arrow key
+                case model of
+                    Default tId _ hErr ->
+                        ( (Default tId -1 hErr, { pModel | currentStates = sModel.machine.start }, sModel), False, Cmd.none)
+                    _ -> 
+                        ( ( model, pModel, sModel ), False, Cmd.none )
+
             else
                 case model of
                     Editing tapeId ->