anchor.diff:  \ ;
   \ 
   \ : isliteral ( ptr -- f)
  -\     dup @ h# 8000 and 0<>
  -\     swap d# 2 + @ h# 608c = and
  +\     dup @i h# 8000 and 0<>
  +\     swap d# 2 + @i h# 608c = and
   \ ;
   \ 
   \ header compile,
   \ : compile,
  -\     dup @ isreturn if
  -\         @ h# ff73 and
  +\     dup @i isreturn if
  +\         @i h# ff73 and
   \         code,
   \     else
   \         dup isliteral if
  -\             @ code,
  +\             @i code,
   \         else
   \             2/ h# 4000 or
   \             code,
  
positive.code: \
  
  : (do)  ( limit start -- start-limit )
      r> rO @ >r >r
      over rO !
      swap -
  ;
  
  : (?do)  ( limit start -- start-limit start!=limit )
      r> rO @ >r >r
      over rO !
      swap -
      dup 0=
  
negative.code: ;
  
  : isnotdelim
      delim @i <>
  ;
  
  header parse
  : parse ( "ccc<char" -- c-addr u )
      delim !
      source >in @i /string
      over >r
      ['] isnotdelim
      _parse
  