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Pet peeve (#rstats wishlist candidate?):
Why does `args(f)` return a whole *function* whose body is NULL? And why must it, in turn, show me a big fat NULL I never asked for?
The first word in `?args` is "Displays ..." - it really doesn't need to return a whole function object and it for sure doesn't need to *display* a NULL!
Literally the only case for this behavior is to meme about the fact this code that reads like a seal barking is a valid expression in R:
```r
> args(args)(args)
NULL
```
TL;DR if you want the more sensible version of `args()` that:
1) Displays the function's arguments and nothing else in the console
2) Returns NULL invisibly
Then just use `str()`* lmao:
```r
args(sum)
#> function (..., na.rm = FALSE)
#> NULL
str(sum)
#> function (..., na.rm = FALSE)
is.null(args(sum)) # nop, it's a function
#> [1] FALSE
is.null(str(sum))
#> function (..., na.rm = FALSE)
#> [1] TRUE
```
* after stripping the "srcref" attribute
@yjunechoe To be fair that’s a solid argument in its favour. 
@klmr LOL I'm actually *just* discovering that:
- NULL in case of a non-function.
So you can just args() all the way down:
...args(args(args(args)(args)))...
I stand corrected. This is indeed solid
@mdsumner Yeah, better! Though it bizarrely prints `NULL` for primitive functions that clearly have user-facing arguments on the R side. Don't even get me started on formals!
https://adv-r.hadley.nz/functions.html?q=formals#primitive-functions