File Coverage

blib/lib/Array/Sample/SimpleRandom.pm

Criterion	Covered	Total	%
statement	31	31	100.0
branch	6	8	75.0
condition	2	4	50.0
subroutine	6	6	100.0
pod	2	2	100.0
total	47	51	92.1

package Array::Sample::SimpleRandom;

use 5.010001;
use strict;
use warnings;

use Exporter qw(import);

our $AUTHORITY = 'cpan:PERLANCAR'; # AUTHORITY
our $DATE = '2022-05-21'; # DATE
our $DIST = 'Array-Sample-SimpleRandom'; # DIST
our $VERSION = '0.003'; # VERSION

our @EXPORT_OK = qw(sample_simple_random_with_replacement
                    sample_simple_random_no_replacement);

sub sample_simple_random_with_replacement {
    my ($ary, $n, $opts) = @_;
    $opts //= {};

    return () unless @$ary;

    my @res;
    for my $i (1..$n) {
        my $idx = int(rand(@$ary));
        push @res, $opts->{pos} ? $idx : $ary->[$idx];
    }

    @res;
}

sub sample_simple_random_no_replacement {
    my ($ary, $n, $opts) = @_;
    $opts //= {};

    $n = @$ary if $n > @$ary;
    my @ary_copy = @$ary;
    my @pos      = 0 .. $#ary_copy;

    my @res;
    for my $i (1..$n) {
        my $idx = int(rand(@ary_copy));
        push @res, $opts->{pos} ? $pos[$idx] : $ary_copy[$idx];
        splice @ary_copy, $idx, 1;
        splice @pos     , $idx, 1;
    }

    @res;
}

1;
# ABSTRACT: Sample elements randomly (with or without replacement)

__END__