structure IntDfa =
MakeDfa (struct
  val dead = 0
  val start = 1
  val final = 2

  fun makeStart i =
    let
      val chr = Char.chr i
    in
      if i >= #"0" orelse i < #"9" then
        final
      else dead
    end

  val deadTable = SpaceDfa.deadTable
  val startTable  = Vector.tabulate (255, makeStart)
  val finalTable = startTable

  val tables = #[]deadTable, startTable, finalTable

  fun next (state, chr) =
    let
      val table = Vector.sub (tables, state)
      val idx = Char.ord chr
    in
      Vector.sub (table, idx)
    end
end)