[Rd] type of list elements in .Call

[Faheem Mitha]

On Mon, 31 Jan 2005, Prof Brian Ripley wrote:

> This is covered, copiously, in the examples in `Writing R Extensions'. 
> Hint: search for coerceVector.

I see. I thought that INTEGER and its relatives did coercion too, but now 
I see that is not stated anywhere.

Eg. REAL is first used in "Writing R Extensions" in 4.7.1 as in

REAL(ab)[0] = 123.45
...

and I cannot find a discussion about what it does previous to that, or 
indeed afterwards.

In Rinternals header file, it says

/* Under the generational allocator the data for vector nodes comes
    immediately after the node structure, so the data address is a
    known ofset from the node SEXP. */

This does not mean much to me. Perhaps a short comment in the 
documentation would be helpful, if not already present.

                                                                   Faheem.