Noel Rappin Writes Here

Notes and Corrections Before we get fully started here, a couple of notes on Better Know Singleton Classes, which, among other things, got mentioned on Hacker News, giving me comments there for the first time in years, maybe for the first time ever. One Hacker News comment suggested that “Eigenclass” was coined by _why the lucky stiff as a joke and was then adopted by the community. I looked this up and that doesn’t seem to be the case… _why’s Poignant Guide To Ruby uses “metaclass” when it discusses this feature (at least the version I have does…).

It is time to Better Know what is perhaps the Ruby-iest of Ruby things, a feature that didn’t even have an official name for several years, despite being critical to Ruby’s Object-Oriented semantics. (It only just now occurs to me that there was no official name in English, I wonder what the Japanese name for it was…). Yes, it’s the singleton class. Which isn’t really a singleton. Or really a class.