Look into what's shown / not shown in examples

[jennybc]

I stumbled across this example:

https://readr.tidyverse.org/reference/write_delim.html?q=excel#ref-examples

# \dontshow{
.old_wd <- setwd(tempdir())
# }
# If only a file name is specified, write_()* will write
# the file to the current working directory.
write_csv(mtcars, "mtcars.csv")
write_tsv(mtcars, "mtcars.tsv")

# If you add an extension to the file name, write_()* will
# automatically compress the output.
write_tsv(mtcars, "mtcars.tsv.gz")
write_tsv(mtcars, "mtcars.tsv.bz2")
write_tsv(mtcars, "mtcars.tsv.xz")
# \dontshow{
setwd(.old_wd)
# }

where the directory setting / re-setting code is being shown, but the intent certainly seems to be to hide it.

We probably need to update some of the example formatting technology.

[jennybc]

Based on searching our code base, this does seem to be our current preferred way of doing this. I don't see any obvious improvement. And yet it is also true that the \dontshow{} is not having the intended effect in pkgdown sites, here in readr and in other package where we use it. Suspect this is a pkgdown issue.

[jennybc]

r-lib/pkgdown#2188

I don't think there's anything to be done about this readr, at least not now.