This is Perl module List::UtilsBy::XS.
INSTALLATION
List::UtilsBy::XS installation is straightforward.
If your CPAN shell is set up, you should just be able to do
% cpan List::UtilsBy::XS
Download it, unpack it, then build it as per the usual:
% perl Makefile.PL
% make && make test
Then install it:
% make install
DOCUMENTATION
List::UtilsBy::XS documentation is available as in POD.
So you can do:
% perldoc List::UtilsBy::XS
to read the documentation online with your favorite pager.
Syohei YOSHIDA