I need to write a dplyr function that creates a customised area plot. So here's my attempt. area_plot <- function(data, what, by){ by <- ensym(by) what <- ensym(what) data %>% f...

Can anybody explain, please, what for do we need !!, !!! or {{}} operators from rlang? I tried to learn more about quasiquotation but did not get anything. I've reached several posts on curly-curly...

The quasiquoted list `(1 ,@2 3) is invalid because 2 is not a list. However, `(1 2 ,@3) is valid and will return a dotted list: (1 2 . 3). I observe this result in Common Lisp and Scheme. Why is it...

In the following when macro: (defmacro when (condition &rest body) `(if ,condition (progn ,@body))) Why is there an "at" @ sign?

I am trying to search a database and then label the ouput with a name derived from the original search, "derived_name" in the reproducible example below. I am using a dplyr pipe %>%, and I am ha...