::  lifted directly from ford, should probably be in zuse
=,  clay
=<  pile-rule
|%
++  pile-rule
  |=  pax=path
  %-  full
  %+  ifix
    :_  gay
    ::  parse optional /? and ignore
    ::
    ;~(plug gay (punt ;~(plug fas wut gap dem gap)))
  |^
  ;~  plug
    %+  cook  (bake zing (list (list taut)))
    %+  rune  hep
    (most ;~(plug com gaw) taut-rule)
  ::
    %+  cook  (bake zing (list (list taut)))
    %+  rune  lus
    (most ;~(plug com gaw) taut-rule)
  ::
    %+  rune  tis
    ;~(plug sym ;~(pfix gap fas (more fas urs:ab)))
  ::
    %+  rune  cen
    ;~(plug sym ;~(pfix gap ;~(pfix cen sym)))
  ::
    %+  rune  buc
    ;~  (glue gap)
      sym
      ;~(pfix cen sym)
      ;~(pfix cen sym)
    ==
  ::
    %+  rune  tar
    ;~  (glue gap)
      sym
      ;~(pfix cen sym)
      ;~(pfix fas (more fas urs:ab))
    ==
  ::
    %+  stag  %tssg
    (most gap tall:(vang & pax))
  ==
  ::
  ++  pant
    |*  fel=^rule
    ;~(pose fel (easy ~))
  ::
  ++  mast
    |*  [bus=^rule fel=^rule]
    ;~(sfix (more bus fel) bus)
  ::
  ++  rune
    |*  [bus=^rule fel=^rule]
    %-  pant
    %+  mast  gap
    ;~(pfix fas bus gap fel)
  --
::
++  taut-rule
  %+  cook  |=(taut +<)
  ;~  pose
    (stag ~ ;~(pfix tar sym))
    ;~(plug (stag ~ sym) ;~(pfix tis sym))
    (cook |=(a=term [`a a]) sym)
  ==
--