[Rd] some questions about R internal SEXP types

[Dan Kortschak]

Thanks, Alex.

That might be good enough for me for this particular concern; in the
absence of a language specification specifying my behaviour and
referring to precedent seems like a reasonable fall back.

Dan

On Tue, 2020-09-08 at 09:33 +0200, Bertram, Alexander wrote:
> Hi Dan,
> 
> For what it's worth, Renjin requires LISTSXPs to hold either a
> LISTSXP or a NULL, and this appears to be largely the case in
> practice based on running tests for thousands of packages (including
> cross compiled C code). I can only remember it being briefly an issue
> with the rlang package, but Lionel graciously changed it:
> https://github.com/r-lib/rlang/pull/579
> 
> Best,
> Alex