structure Token =
struct
  datatype t =
    AND
  | ANDALSO
  | AS
  | CASE
  | DATATYPE
  | ELSE
  | END
  | EXCEPTION
  | FN
  | FUN
  | HANDLE
  | IF
  | IN
  | INFIX
  | INFIXR
  | LET
  | LOCAL
  | NONFIX
  | OF
  | OP
  | OPEN
  | ORELSE
  | RAISE
  | REC
  | THEN
  | TYPE
  | VAL
  | WITH
  | WITHTYPE
  | WHILE
  | L_PAREN
  | R_PAREN
  | L_SQUARE_BRACKET
  | R_SQUARE_BRACKET
  | L_BRACE
  | R_BRACE
  | COMMA
  | COLON
  | SEMICOLON
  | TRIPLE_DOT
  | UNDERSCORE
  | PIPE
  | EQ_ARROW
  | DASH_ARROW
  | HASH

  | BOOL of bool
  | INT of int
  | WORD of word
  | REAL of real
  | CHAR of char
  | STRING of string
end