Generalizing Support for Functional OOP in R R has built-in support for two functional Object Oriented Programming (OOP) systems: S3 and S4, corresponding to the third and fourth version of the S language, respectively. The two systems are largely compatible; however, they are two fundamentally distinct systems, two systems for a user to understand, two systems for a developer to contend with when making their package interoperate with another, two systems for R core to maintain. S7 is a new OOP...