Hi,
I tend to agree with the objections expressed earlier. I would only
add that making the NULL pointer semantically equivalent to NA would
introduce a precedent that could lead to some confusion. For example
it would set the expectation that CHAR(Rf_mkChar(NULL)) is NULL,
which is not the case AFAIK. Or that low-level string manipulation
utilities that take a C-string as input (e.g. Rf_reEnc()) accept NULL
and propagate it.
Of course these things can be modified to be consistent with the new
"NULL pointer == NA" paradigm but this might end up being a bigger move
than what it seems at first sight...
Cheers,
H.
On 05/25/2016 08:43 AM, luke-tier...@uiowa.edu wrote:
On Wed, 25 May 2016, Tim Keitt wrote:
On Wed, May 25, 2016 at 7:22 AM, Michael Lawrence
<lawrence.mich...@gene.com
wrote:
On Wed, May 25, 2016 at 4:23 AM, Jeroen Ooms <jeroen.o...@stat.ucla.edu>
wrote:
I'm not disagreeing with what's been said in this thread, but I can't
help
but recall that I brought up this exact issue probably 15 years ago
and was
told (by Brian, I believe) "don't do that" (pass a null pointer),
which was
perfectly fine. The real issue was not the behavior but that it was not
documented or consistent. I've lived by the mantra since that you can
never
trust a pointer in R code. User must always check for NULL.
In _C_ code. This is true whether you are calling into the R C API or
any other C library: you as the C programmer need to make sure either
that passing NULL is OK or make sure you don't do that.
I wouldn't object to mkXXX checking for NULL and signaling an error
instead of segfaulting, but good C code calling mkXXX should still
typically do its own check and handle the situation in an appropriate
way.
Best,
luke
I just wrote my own functions mkXXX_safe that wrap the internals and
check
the pointer.
THK
http://www.keittlab.org/
[[alternative HTML version deleted]]
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
--
Hervé Pagès
Program in Computational Biology
Division of Public Health Sciences
Fred Hutchinson Cancer Research Center
1100 Fairview Ave. N, M1-B514
P.O. Box 19024
Seattle, WA 98109-1024
E-mail: hpa...@fredhutch.org
Phone: (206) 667-5791
Fax: (206) 667-1319
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
