[Rd] Build a R call at C level

[Jan Gorecki]

It is quite known that R documentation on R C api could be improved...
Still R-package-devel mailing list should be preferred for this kind
of questions.
Not sure if that is the best way, but works.

call_to_sum <- inline::cfunction(
  language = "C",
  sig = c(x = "SEXP"), body = "

SEXP e = PROTECT(lang2(install(\"sum\"), x));
SEXP r_true = PROTECT(CONS(ScalarLogical(1), R_NilValue));
SETCDR(CDR(e), r_true);
SET_TAG(CDDR(e), install(\"na.rm\"));
Rf_PrintValue(e);
SEXP ans = PROTECT(eval(e, R_GlobalEnv));
UNPROTECT(3);
return ans;

")

call_to_sum(c(1L,NA,3L))

On Tue, Jun 30, 2020 at 10:08 AM Morgan Morgan
<morgan.emailbox using gmail.com> wrote:
>
> Hi All,
>
> I was reading the R extension manual section 5.11 ( Evaluating R expression
> from C) and I tried to build a simple call to the sum function. Please see
> below.
>
> call_to_sum <- inline::cfunction(
>   language = "C",
>   sig = c(x = "SEXP"), body = "
>
> SEXP e = PROTECT(lang2(install(\"sum\"), x));
> SEXP ans = PROTECT(eval(e, R_GlobalEnv));
> UNPROTECT(2);
> return ans;
>
> ")
>
> call_to_sum(1:3)
>
> The above works. My question is how do I add the argument "na.rm=TRUE" at C
> level to the above call? I have tried various things based on what is in
> section 5.11 but I did not manage to get it to work.
>
> Thank you
> Best regards
>
>         [[alternative HTML version deleted]]
>
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