### gather schachteln?

{
    my $list_ref=[];

    sub gather (&){
	my $code_ref=shift;

	my @list=();
	my $safe=$list_ref;
	$list_ref=\@list;

	&$code_ref;

	$list_ref=$safe;

	return @list;
    }

    sub take  {
	push @$list_ref, @_;
	return;
    }
}


#-  simple test

@x= gather{ take [$_] for (1..3) };

print Dumper \@x;
   
#-  nested test

@x=();

@x= gather{
    take
	gather{ my $x=$_;
		take [$_,$x] for (1..$x)
	    } for (1..5);
   };

print Dumper \@x;