anchor.diff:                      | _ -> ()
                       vimState
                   | Delete -> delete vimState start finish
  +                | DeleteLeft -> if editor.CaretColumn > 1 then delete vimState (editor.CaretOffset - 1) editor.CaretOffset else vimState
                   | Change -> 
                       let state = delete vimState start finish
                       switchToInsertMode state
  
positive.code:             | NormalMode, [ "C" ] -> [ run Change EndOfLine ]
              | NormalMode, [ "D" ] -> [ run Delete EndOfLine ]
              | NormalMode, [ "x" ] -> [ run Delete CurrentLocation; run Move EnsureCursorBeforeDelimiter ]
              | NormalMode, [ "s"] -> [ run Delete CurrentLocation; run Move EnsureCursorBeforeDelimiter; switchMode InsertMode ]
              | NormalMode, [ "p" ] -> [ run (Put After) Nothing ]
              | NormalMode, [ "P" ] -> [ run (Put Before) Nothing ]
  
negative.code:     | Yank
      | Put of BeforeOrAfter
      | Delete
      | DeleteLeft
      | BlockInsert
      | Change
      | SwitchMode of VimMode
  