(I attached a vignette as PDF showing this with nicer layout)

As a good friend of @lintr-bot, I found out it was impossible to satisfy him/her/it in the following occasion:

Suppose a 3D matrix:

m <- array(1:8, c(2, 2, 2))

Let's say I want the 2nd columns of the second depth.

Here, lintr will complain about the presence of a
space before the comma before the second 2:

a <- m[2, , 2]

Here, lintr will complain about the space absent after the comma of
the first 2:

b <- m[2,, 2]

This results in the following errors:

bug_report_lintr.Rmd:24:11: style: Commas should never have a space before.
a <- m[2, , 2]
bug_report_lintr.Rmd:31:10: style: Commas should always have a space after.
b <- m[2,, 2]

Thus, there is no correct formatting possible here. I suggest to allow one of these formats :-)

Thanks for lintr and @lintr-bot !

Vignette here: bug_report_lintr.pdf