[R] More questions about R extension programming

[Edzer J. Pebesma]

I have been strugling to get character data in and out of c functions
using the .Call() interface, but I don't succeed getting them back
into R.

The example:

#include "R.h"
#include "Rdefines.h"

char *cp = "xxxyyyy";
SEXP do_char(SEXP c) {
    int i;
    SEXP s;

    for (i = 0; i < LENGTH(c); i++)
        printf("%d:[%s]\n", i, CHARACTER_DATA(STRING_ELT(c,i)));
        /* CHARACTER_VALUE() does not work here! */
    s = NEW_CHARACTER(1);
    CHARACTER_POINTER(s) = cp;
    c = NEW_CHARACTER(3);
    SET_STRING_ELT(c,0, s);
    SET_STRING_ELT(c,1, s);
    SET_STRING_ELT(c,2, s);
    return c;
}

works only for the first half; but I can't manage to fill the string
and return it back.

Note that I had to use CHARACTER_DATA instead of CHARACTER,
which Thomas Lumley suggested last Saturday.
--
Edzer