as.numeric( NULL ) is not silent, it is very explicit. Re this not being a C++ NULL, I don't object to R NULL being used that way (in fact it may be more sensible to do this than not, but it is not clear that R core thinks this way).
On April 18, 2018 9:53:12 AM CDT, Serguei Sokol <serguei.so...@gmail.com> wrote: >Le 18/04/2018 à 16:15, Jeff Newmiller a écrit : >> Regarding: >> >> "Actually, when NULL is provided to where a vector or a matrix is >expected just an error is thrown. So we can hardly imagine that someone >would have his program broken or will be misled if such coercion is >introduced." >> >> If all programs were perfect this would be true, but the ability to >identify incorrect pointer initialization is an important feature for >testing. >> >> In the late '90s, some Internet Service Providers tried to "assist" >users who typed bad site names into browsers by making failed DNS >lookups redirect to a server prepared to supply an informative "were >you looking for X?" web page. This caused significant disruption in >non-user-interactive network protocols that relied on getting a failure >notice for bad DNS lookups, and that idea had to go to the trash heap >eventually. >Interesting example but not really "parallel" to our situation. >In R, we already have as.numeric(NULL) without such kind of >catastrophe. >I just propose an equivalent functioning in Rcpp. > >> >> I don't have failed code tests to offer for this, but the idea of >silently replacing a C++ NULL with a valid value is anathema. >It's not C++ NULL which is coerced (not "replaced") to a vector but R's >one. And only where a vector of a given type is expected, not >everywhere. > >I think there is a possible compromise. >We can introduce an automatic coercion in #ifdef'ed blocks with e.g. >RCPP_COERCE_NULL_TO_VECTOR and RCPP_COERCE_VECTOR_TO_MARIX optional >macros. >In such a way, those who want this feature can have it by defining >these macros before including Rcpp.h and those who consider it as >anathema can go a >traditional way of doing. > >Serguei. -- Sent from my phone. Please excuse my brevity. _______________________________________________ Rcpp-devel mailing list Rcpp-devel@lists.r-forge.r-project.org https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
