|%
+$  states   ?(%unknown %create)
+$  token    ?(%create tape)
++  resolve-face
  |=  [buffer=tape pos=[@ud @ud]]
  ^-  @t
  ~|  "Cannot parse {<pos>} to face"
  `@t`(scan (flop buffer) sym)
++  resolve-unknown
  |=  [buffer=tape pos=[@ud @ud]]
  ^-  [states token]
  ~|  "Cannot parse {<pos>}"
  ?:  =('etaerc' (crip (cass buffer)))
    [%create %create]
  !!
++  parse
  |=  script=tape
  ~|  'Input script is empty.'
  ?>  !=((lent script) 0)
  ^-  (list token)
  =/  tokens  `(list token)`~
  =/  buffer  `tape`~
  =/  state   `states`%unknown
  =/  script-position  [1 1]
  =/  buffer-position  [1 1]
  |-
  ::  https://github.com/urbit/arvo/issues/1024
  ::
  ?:  =(~ script)
    ?:  &(=((lent tokens) 0) =((lent buffer) 0))
      ~|  "no input"
      !!
    ?-  state
      %unknown
        ~&  "state is: {<state>}"
        ~&  "tokens is: {<tokens>}"
        ~&  "buffer is: {<buffer>}"
        ~|  "incomplete statement {<buffer-position>}"
        !!
      %create
        tokens
        :: (flop `(list token)`[(resolve-face [buffer buffer-position]) tokens])
    ==
  ?-  state
    %unknown
      !!
    %create
      !!
  ==
--