File Coverage

blib/lib/Role/TinyCommons/Collection/PickItems/RandomPos.pm

Criterion	Covered	Total	%
statement	6	21	28.5
branch	0	10	0.0
condition	0	2	0.0
subroutine	2	3	66.6
pod	0	1	0.0
total	8	37	21.6

package Role::TinyCommons::Collection::PickItems::RandomPos;

use Role::Tiny;
use Role::Tiny::With;

our $AUTHORITY = 'cpan:PERLANCAR'; # AUTHORITY
our $DATE = '2024-01-16'; # DATE
our $DIST = 'Role-TinyCommons-Collection'; # DIST
our $VERSION = '0.010'; # VERSION

requires 'get_item_count';
requires 'get_item_at_pos';

with 'Role::TinyCommons::Collection::PickItems';

sub pick_items {
    my ($self, %args) = @_;

    my $n = $args{n} || 1;
    my $allow_resampling = defined $args{allow_resampling} ? $args{allow_resampling} : 0;
    my $item_count = $self->get_item_count;

    # got an infinite collection?
    if ($item_count == -1) {
        warn "Got infinite item count (-1), setting item_count = 2**31 -1";
        $item_count = 2**31 - 1;
    }

    $n = $item_count if $n > $item_count;

    my @items;
    my %used_pos;
    while (@items < $n) {
        my $pos = int(rand() * $item_count);
        unless ($allow_resampling) {
            next if $used_pos{$pos}++;
        }
        push @items, $self->get_item_at_pos($pos);
    }
    @items;
}

1;
# ABSTRACT: Provide pick_items() that picks items by random positions

__END__