Metaprogramming: Difference between revisions

R does not have much to offer in this regard. It has generic functions, but they're little more than the forbidden option of operator overloading. We equally cannot use any eval tricks, because the task has also forbidden those. As for macros, although R is inspired by Scheme, it has nothing of the sort. For example, see the admitted cheating in [[Extend your language#R]].

As for the permitted things that R does have, it makes it very easy to define new infix operators. We have shown one such example at [[Matrix-exponentiation operator#Infix operator]]. To my knowledge, this is only documented in 'An Introduction to R', [https://cran.r-project.org/doc/manuals/r-release/R-intro.html#Defining-new-binary-operators section 10.2]. As for doing this ourselves, we will implement a version of the "nCk" syntax that some calculators use for "n choose k", i.e. the binomial coefficient: