R help - Jul 2007 - Unrecognising SEXP [C file compilation using .Call]

Following an exercise suggestion I went to compile a C file, now with the .Call
interface to R. The C file is:

 

#include <R.h>

#include <Rdefines.h>    

SEXP getInt(SEXP myint, SEXP myintVar) {

 

  int Imyint, n; // declare an integer variable

  int *Pmyint;   // pointer to an integer vector

  PROTECT(myint = AS_INTEGER(myint));

   Imyint = INTEGER_POINTER(myint)[0];

   Pmyint = INTEGER_POINTER(myint);

   n = INTEGER_VALUE(myintVar);

   printf(" Printed from C: \n");

   printf(" Imyint: %d \n", Imyint);

   printf(" n: %d \n", n);

   printf(" Pmyint[0], Pmyint[1]: %d %d \n", 

                         Pmyint[0], Pmyint[1]);

   UNPROTECT(1);

   return(R_NilValue);

}

 

Compiling with R CMD SHLIB or with any specific compiler to C/C++ gave an
unrecognition of SEXP.

What actually is SEXP? What is for? Why wasn't recognized?

 

Thanks again,

Diogo Andre' Alagador

	[[alternative HTML version deleted]]