Function Generators vs Partial Application in R

In which I confront the way I read code in different languages, and end up wishing that R had a feature that it doesn&rsquo;t. This is a bit of a thought-dump as I consider some code - please don&rsquo;t take it as a criticism of any design choices; the tidyverse team have written magnitudes more code that I have and have certainly considered their approach more than I will. I believe it&rsquo;s…