Third Script: Second Draft

colomon on 2008-12-27T14:03:16

After a lot of really helpful suggestions from Aristotle, here is my second version of the third script. This version feels much more satisfyingly Perl6ish to me.

my $votes_file = "votes.txt";

sub EffectiveVote ( Str $vote, Hash %skip ) {
    return $vote.split( ',' ).first( { ! %skip{$_}.defined } )
        // die "No valid vote?!";
}

sub CountRound (Array @votes, Hash %skip)
{
    my %count;
    for @votes -> $vote
    {
        %count{EffectiveVote($vote, %skip)}++;
    }
    return %count;
}

my @votes = do
{
    my $votes = open($votes_file);
    =$votes;
}

my $count = 0;
my %skip;

loop
{
    say "\nRound {++$count}";
    my @ranking = CountRound(@votes, %skip).pairs.sort({.value}).reverse;
    
    say sprintf("%s: %s", .key, .value / @votes.elems)
        for @ranking;
    
    my $top_rank = @ranking[0];
    if ($top_rank.value > @votes.elems / 2)
    {
        say "\nThe winner is {$top_rank.key} with {$top_rank.value / @votes.elems * 100.0}% of the vote.";
        exit;
    }

    my $skip = @ranking.pop.key;
    %skip{$skip} = 1;
    say "Dropping $skip";
}