File Coverage

blib/lib/List/Util/groupby.pm

Criterion	Covered	Total	%
statement	11	52	21.1
branch	0	6	0.0
condition	0	9	0.0
subroutine	4	6	66.6
pod	2	2	100.0
total	17	75	22.6

package List::Util::groupby;

use 5.010001;
use strict;
use warnings;

use Exporter 'import';

our $AUTHORITY = 'cpan:PERLANCAR'; # AUTHORITY
our $DATE = '2023-11-20'; # DATE
our $DIST = 'List-Util-groupby'; # DIST
our $VERSION = '0.004'; # VERSION

our @EXPORT_OK = qw(
                       groupby
                       hgroupby
               );

sub groupby(&;@) { ## no critic: Subroutines::ProhibitSubroutinePrototypes
    my $code = shift;

    my @result;
    my $index = -1;
    for my $item (@_) {
        $index++;
        my $result_index;
        { local $_ = $item; $result_index = $code->($item, $index) }
        if (ref($result_index) eq 'ARRAY') {
            my $temp = \@result;
            for my $i (0 .. $#{ $result_index }) {
                $temp->[ $result_index->[$i] ] //= [];
                $temp = $temp->[ $result_index->[$i] ];
            }
            push @$temp, $item;
        } else {
            $result[$result_index] //= [];
            push @{ $result[$result_index] }, $item;
        }
    }
    @result;
}

sub hgroupby(&;@) { ## no critic: Subroutines::ProhibitSubroutinePrototypes
    my $code = shift;

    my %result;
    my $index = -1;
    for my $item (@_) {
        $index++;
        my $result_index;
        { local $_ = $item; $result_index = $code->($item, $index) }
        if (ref($result_index) eq 'ARRAY') {
            my $temp = \%result;
            for my $i (0 .. $#{ $result_index }) {
                $temp->{ $result_index->[$i] } //= $i == $#{ $result_index } ? [] : {};
                $temp = $temp->{ $result_index->[$i] };
            }
            push @$temp, $item;
        } else {
            $result{$result_index} //= [];
            push @{ $result{$result_index} }, $item;
        }
    }
    %result;
}

1;
# ABSTRACT: Group items of a list into several (possibly multilevel) buckets

__END__