Yihui Xie / 2023-02-06
Base R has had the function
isTRUE() for many years, and I had wished for a
few years that there were an
isFALSE(), too. I had used
many times before I added it to the first version of the xfun package as the
isFALSE(). The xfun package was first released to CRAN on
Three months later (2018-04-23), R 3.5.0 was released, which included a function
isFALSE() in the base package. Apparently another mind was thinking like
me (which turned out to be Martin Mächler).
Last year Martin sent a pull request to
isFALSE() from xfun, which was what I wished to do for a long time,
but I couldn’t just remove it, because it was used in quite a few of packages
that I maintain. Recently I have removed the usage in them and checked all
reverse dependencies of xfun. It seems no other packages would be affected
if I deprecate
xfun::isFALSE(), which is good news. I’m not sure if it is used
in non-package code by anyone, though.
Anyway, I’m announcing the deprecation of
xfun::isFALSE() today (I hope it is
the first and also the last time that you have heard of this function). For now,
it will throw an error during
R CMD check if you still use it in a package. In
future, it will simply throw an error if
base::isFALSE() exists. In the end,
I’ll just remove it from xfun, and you should use
isFALSE() in base R
instead. I wish it won’t have much impact on your code. I apologize if it does.
Had I waited for three more months, I wouldn’t have this trouble. Timing can be funny sometimes.