PerlでRubyのEnumerable#group_by

group_by.pl

sub group_by(&@) {
  my $block = shift;
  my %result;
  
  for (@_) {
    my $key = $block->($_);
    $result{$key} = [] unless exists $result{$key};
    push @{ $result{$key} }, $_;
  }

  return \%result;
}

group_by { $_ % 2 } (0..9);