Anonymous user
Rock-paper-scissors: Difference between revisions
add Mercury
(Added Prolog implementation) |
(add Mercury) |
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Line 3,330:
"You win.", _, "Draw."]];
Column@{Dynamic[text], ButtonBar[# :> play[#] & /@ choices]}]</lang>
=={{header|Mercury}}==
{{trans|Prolog}}
<lang Mercury>:- module rps.
:- interface.
:- import_module io.
:- pred main(io::di, io::uo) is det.
:- implementation.
:- use_module random, exception.
:- import_module list, string.
:- type play
---> rock
; paper
; scissors.
:- pred beats(play, play).
:- mode beats(in, in) is semidet.
beats(rock, scissors).
beats(paper, rock).
beats(scissors, paper).
:- pred random(play::out, random.supply::mdi, random.supply::muo) is det.
random(Play, !RS) :-
random.random(1, 3, N, !RS),
( if N = 1 then
Play = rock
else if N = 2 then
Play = paper
else
Play = scissors
).
main(!IO) :-
seed(Seed, !IO),
random.init(Seed, RS),
play(RS, !IO).
:- pred play(random.supply::mdi, io::di, io::uo) is det.
play(!.RS, !IO) :-
io.write_string("Your choice? ", !IO),
io.read(Res, !IO),
(
Res = ok(Play),
random(Counter, !RS),
io.format("The computer chose %s\n", [s(string(Counter))], !IO),
( if beats(Counter, Play) then
io.write_string("Computer wins.\n", !IO)
else if beats(Play, Counter) then
io.write_string("You win!\n", !IO)
else
io.write_string("It is a draw\n", !IO)
),
play(!.RS, !IO)
;
Res = eof
;
Res = error(_, _),
exception.throw(Res)
).
:- pragma foreign_decl("C", "#include <time.h>").
:- pred seed(int::out, io::di, io::uo) is det.
:- pragma foreign_proc("C",
seed(Seed::out, _IO0::di, _IO::uo),
[promise_pure, will_not_call_mercury],
"
Seed = time(NULL);
").</lang>
=={{header|OCaml}}==
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