Hi All, I have some questions regarding the R C API.
Let's assume I have a function which is defined as follows: R file: myfunc <- function(a, b, ...) .External(Cfun, a, b, ...) C file: SEXP Cfun(SEXP args) { args = CDR(args); SEXP a = CAR(args); args = CDR(args); SEXP b = CAR(args); args = CDR(args); /* continue to do something with remaining arguments in "..." using the same logic as above*/ return R_NilValue; } 1/ Let's suppose that in my c function I change the value of a inside the function but I want to reset it to what it was when I did SEXP a = CAR(args); . How can I do that? 2/Is there a method to set "args" at a specific position so I can access a specific value of my choice? If yes, do you have an simple example? 3/ Let's suppose now, I call the function in R. Is there a way to avoid the function to evaluate its arguments before going to the C call? Do I have to do it at the R level or can it be done at the C level? Thank you very much in advance. Best regards Morgan [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel