type token = | Id of string| Key of string| Proof of string * string| Word| Eof
val open_file : string -> inputval close : input -> unitval error :
input ->
('a, Stdlib.Format.formatter, unit, 'b) Stdlib.format4 ->
'aval key : input -> string -> boolval eat : input -> string -> unitval ident : input -> stringval idents : input -> string listval filter : string -> string option