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(*
//
// This code is based on some code by
// Eli Frey (eli.frey AT gmail DOT com)
//
// Minor modification by Hongwei Xi (gmhwxi AT gmail DOT com)
//
// Time: July 18-19, 2012
//
*)
(* ****** ****** *)
//
#include
"share/atspre_staload.hats"
//
(* ****** ****** *)
//
staload "libats/ML/SATS/string.sats"
//
staload _ = "libats/ML/DATS/string.dats"
//
(* ****** ****** *)
#define nil stream_nil
#define cons stream_cons
#define :: stream_cons
(* ****** ****** *)
fun
from{n:int} (
n: intGte(n)
) :<!ntm> stream (intGte(n)) = $delay(n :: from{n+1}(n+1))
(* ****** ****** *)
typedef sstring = stream string
(* ****** ****** *)
fun morse
(n: Nat):<!laz> sstring = let
//
fn add_dot (str: string):<> string = "." + str
fn add_dash (str: string):<> string = "-" + str
//
fn go (n: Nat):<> sstring = $effmask_all
(
case+ n of
| 0 => $delay ("" :: $delay (nil))
| 1 => $delay ("." :: $delay (nil))
| n =>> let
val add_dots = stream_map_fun( morse( n-1 ), add_dot )
val add_dashes = stream_map_fun( morse( n-2 ), add_dash )
in
stream_merge_fun( add_dots, add_dashes, lam (_, _) => 0 )
end // end of [n]
) // end of [go]
in
stream_nth_exn (stream_map_fun(from{0}(0), go), n)
end // end of [morse]
(* ****** ****** *)
staload STDIO = "libc/SATS/stdio.sats"
(* ****** ****** *)
implement
main0 () =
{
//
val xs = morse (5)
val xs = stream2list (xs)
val () = list_vt_foreach_fun (xs, lam (x) =<1> $STDIO.puts_exn (x))
val () = list_vt_free (xs)
//
} // end of [main]
(* ****** ****** *)
(* end of [morse_enum.dats] *)
|
