Hack for trailing separator

(* [jmseparated_list(separator, X)] recognizes a possibly empty list of
   [X]'s, separated with [separator]'s. It produces a value of type
   ['a list] if [X] produces a value of type ['a]. The front element
   of the list is the first element that was parsed. *)

%public %inline jmseparated_list(separator, X):
  xs = loption(jmseparated_nonempty_list(separator, X))
    { xs }

(* [separated_nonempty_list(separator, X)] recognizes a nonempty list
   of [X]'s, separated with [separator]'s. It produces a value of type
   ['a list] if [X] produces a value of type ['a]. The front element
   of the list is the first element that was parsed. *)

%public jmseparated_nonempty_list(separator, X):
  x = X
    { [ x ] }
| x = X; separator; xs = jmseparated_list(separator, X)
    { x :: xs }