In the first and second parts of this blog series, I defined lexical and dynamic scope, and demonstrated interesting cases of scoping in R.

In this third and final part of my blog series, I’d like to discuss a paper by the creators of R, where they motivate the need for lexical scoping in a statistical programming language.

This is a “bonus” blog post, because I’m going to dive into some of the hairier R features to show how four different kinds of scoping can be simulated in R.

In the previous post of this three-part blog series, we discussed lexical and dynamic scope. Now, in this second part, we can return to the original question: is R lexically or dynamically scoped?

This all started with a simple question about the R programming language: is R lexically or dynamically scoped?

To answer that question, we need to understand what scope is, along with lexical scope and dynamic scope.