Using Perl's custom keyword mechanism we can add new syntax and features, even to versions of Perl released years ago. As it stands, the core mechanism is very low-level and hard to use correctly, but there is a better way.
We'll first take a look at some existing modules that provide syntax extensions, and demonstrate that most of them work as far back as Perl 5.16, even though the modules themselves are much newer than this. We'll then take a brief look at how early versions of those modules were implemented, to demonstrate what is involved in that. Finally we shall take a look at a newer, much simpler method of providing the same - along with a list of benefits and other attractions of this new technique.
https://docs.google.com/presentation/d/1wYXcf6ZmbG7o_OHmrfCMbVLGcYrahpaAjuJYR3_vePU/edit
