

Task
Produce a graphical or ASCII-art representation of a Peano curve of at least order 3.

  [ $ "turtleduck.qky" loadfile ] now!
 
  [ stack ]                      is switch.arg (   --> [ )
 
  [ switch.arg put ]             is switch     ( x -->   )
 
  [ switch.arg release ]         is otherwise  (   -->   )
 
  [ switch.arg share 
    != iff ]else[ done  
    otherwise ]'[ do ]done[ ]    is case       ( x -->   )
 
  [ $ "" swap witheach 
      [ nested quackery join ] ] is expand     ( $ --> $ )
 
  [ $ "F" ]                      is F          ( $ --> $ )
 
  [ $ "L" ]                      is L          ( $ --> $ )
 
  [ $ "R" ]                      is R          ( $ --> $ )
 
  [ $ "AFBFARFRBFAFBLFLAFBFA" ]  is A          ( $ --> $ )
 
  [ $ "BFAFBLFLAFBFARFRBFAFB" ]  is B          ( $ --> $ )
 
  $ "A"
 
  4 times expand
 
  turtle
  witheach
    [ switch
        [ char F case [  4 1 walk ]
          char L case [ -1 4 turn ]
          char R case [  1 4 turn ]
          otherwise ( ignore ) ] ]