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