Better Know A Ruby Thing: Method Lookup – Noel Rappin Writes Here

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…). Matz used “eigenclass” in the O’Reilly Ruby book. (You didn’t ask, but version 1 of the Pickaxe uses “singleton class”, per https://ruby-doc.com/docs/ProgrammingRuby/).