component factorial
  (* Bugs: Uses 64-bit signed ints instead of unlimited nats
  (which are not yet implemented); thus breaks at about 13!. 
  Comments have render bugs, so this was removed. *)
  
  import List.{...}
  export Executable

(*  string_to_ZZ64(s:String):ZZ64 = do

    nlist = <| digit | digit <- s |>.reverse()
    numerals = <| n | n <- "0123456789" |>

    SUM[x <- 0:(|nlist| - 1)] numerals.indexOf(nlist[x]) 10^x
  end
*)

  run (args:String...):() = do
--    n = string_to_ZZ64(args[0])
    n = n.cast(ZZ64)
    fact = n!
    println(fact)
  end
end