package Series;

use strict;
use warnings;
use feature qw<say>;

use Exporter qw<import>;
our @EXPORT_OK = qw<slices>;

sub slices {
    my ($args) = @_;

    my $series       = $args->{series};
    my $slice_length = $args->{sliceLength};

    # order of error checking does matter
    die "slice length cannot be zero"     if $slice_length == 0;
    die "slice length cannot be negative" if $slice_length < 0;
    die "series cannot be empty" if ($series eq "");
    die "slice length cannot be greater than series length"
        if $slice_length > length $series;

    my @slices;

    foreach my $index ( 0 .. (length $series) - $slice_length ) {
        push @slices => substr( $series, $index, $slice_length );
    }

    return \@slices;
}

1;