File Coverage

blib/lib/List/StackBy.pm

Criterion	Covered	Total	%
statement	21	21	100.0
branch	2	2	100.0
condition	5	9	55.5
subroutine	5	5	100.0
pod	1	1	100.0
total	34	38	89.4

package List::StackBy;

use 5.020000;
use strict;
use warnings;
use base qw(Exporter);

our $VERSION = '0.01';

our %EXPORT_TAGS = ( 'all' => [ qw(
	stack_by
) ] );

our @EXPORT_OK = ( @{ $EXPORT_TAGS{'all'} } );

our @EXPORT = qw(
  stack_by
);

sub stack_by(&@) {
  my $code = shift;
  my @result;
  my $prev_key;

  for (@_) {
    my $cur_key = $code->( $_ );

    if (not(ref $prev_key)
     or not(defined $cur_key)
     or not(defined $$prev_key)
     or not($cur_key eq $$prev_key)) {

      push @result, [];
    }

    push @{ $result[-1] }, $_;

    $prev_key = \$cur_key;
  }

  return @result;
}

1;

__END__