> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/perl6-rosettacode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trizen.gitbook.io/perl6-rosettacode/programming_tasks/p/penneys_game.md).

# Penney's game

```perl
enum Coin <Heads Tails>;
enum Yay <Yay Good Super Hah Ooh Yipee Sweet Cool Yes Haha>;
enum Boo <Drat Darn Crumb Oops Rats Bah Criminy Argh Shards>;
enum Bozo «'Dude' 'Cha' 'Bzzt' 'Hey' 'Silly dilly' 'Say what!?' 'You numbskull'»;

sub flipping {
    for 1..4 {
        print "-\b";  sleep .1;
        print "\\\b"; sleep .1;
        print "|\b";  sleep .1;
        print "/\b";  sleep .1;
    }
}
 
sub your-choice($p is copy) {
    loop (my @seq; @seq != 3; $p = "{Bozo.pick}! Please pick exactly 3: ") {
        @seq = prompt($p).uc.comb(/ H | T /).map: {
            when 'H' { Heads }
            when 'T' { Tails }
        }
    }
    @seq;
}
 
repeat until prompt("Wanna play again? ").lc ~~ /^n/ {
    my $mefirst = Coin.roll;
    print tc "$mefirst I start, {Coin(+!$mefirst).lc} you start, flipping...\n\t";
    flipping;
    say my $flip = Coin.roll;

    my @yours;
    my @mine;

    if $flip == $mefirst {
        print "{Yay.pick}! I get to choose first, and I choose: "; sleep 2; say @mine = |Coin.roll(3);
        @yours = your-choice("Now you gotta choose: ");
        while @yours eqv @mine {
            say "{Bozo.pick}! We'd both win at the same time if you pick that!";
            @yours = your-choice("Pick something different from me: ");
        }
        say "So, you'll win if we see: ", @yours;
    }
    else {
        @yours = your-choice("{Boo.pick}! First you choose: ");
        say "OK, you'll win if we see: ", @yours;
        print "In that case, I'll just randomly choose: "; sleep 2; say @mine = Coin(+!@yours[1]), |@yours[0,1];
    }
     
    sub check($a,$b,$c) {
        given [$a,$b,$c] {
            when @mine  { say "\n{Yay.pick}, I win, and you lose!"; Nil }
            when @yours { say "\n{Boo.pick}, you win, but I'll beat you next time!"; Nil }
            default     { Coin.roll }
        }
    }

    sleep 1;
    say < OK! Ready? Right... So... Yo!>.pick;
    sleep .5;
    say ("Pay attention now!",
        "Watch closely!",
        "Let's do it...",
        "You feeling lucky?",
        "No way you gonna win this...",
        "Can I borrow that coin again?").pick;
    sleep 1;
    print "Here we go!\n\t";
    for |Coin.roll(3), &check ...^ :!defined {
        flipping;
        print "$_ ";
    }
}
```

Note: the actual run displays a little coin-flipping animation, but that won't show up here:

```
Heads I start, tails you start, flipping...
        Heads
Yipee! I get to choose first, and I choose: Heads Heads Tails
Now you gotta choose: tth
So, you'll win if we see: Tails Tails Heads
Yo!
Can I borrow that coin again?
Here we go!
        Tails Tails Tails Tails Tails Heads 
Argh, you win, but I'll beat you next time!
Wanna play again? y
Tails I start, heads you start, flipping...
        Tails
Yes! I get to choose first, and I choose: Heads Tails Tails
Now you gotta choose: H T T
Dude! We'd both win at the same time if you pick that!
Pick something different from me: heads tails tails
Silly dilly! We'd both win at the same time if you pick that!
Pick something different from me: h,h,h
So, you'll win if we see: Heads Heads Heads
OK!
You feeling lucky?
Here we go!
        Tails Tails Tails Heads Heads Heads 
Drat, you win, but I'll beat you next time!
Wanna play again? y
Heads I start, tails you start, flipping...
        Tails
Shards! First you choose: tht
OK, you'll win if we see: Tails Heads Tails
In that case, I'll just randomly choose: Tails Tails Heads
Right...
Pay attention now!
Here we go!
        Heads Tails Tails Heads 
Hah, I win, and you lose!
Wanna play again? n
```


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://trizen.gitbook.io/perl6-rosettacode/programming_tasks/p/penneys_game.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.