I thought %% was some sort of macro expansions and that is how magrittr creates pipes. But browsing through the magrittr github repo, it looks like they just define %>% and the other pipes as functions [1].

I don't actually know the relation between magrittr and the RStudio shortcut, but I've always assumed a shortcut for typing the pipe characters exist because RStudio employs Hadley Wichkham, who in turn is really big on tidyverse and pipes.

Would %>% mean anything in R if you didn't import magrittr?

[1] https://github.com/tidyverse/magrittr/blob/8b3d510f2a333b224...

All %fun% constructs are just simple functions that can be created by the user and can be used as infix operators. Base R has a few of those: %in%, %o%, %*%, %x%, %%, %/%.

magrittr created %>% which, when used in infix: x %>% f() calls the function on the right side with the argument on the left side f(x).

There are package that provide tons more. For example: https://github.com/moodymudskipper/inops . And you can easily create your own:

    `%sum%` <- function(x, y) x + y

    1 %sum% 2
    [1] 3

To define a new binary operator in R (which are just functions), it must be between % characters.

%>% does not mean anything in base R.