Hi Gabor,
Calling back to an R function from the ALTREP function is not safe.
There has been a heated discussion on why you should not do it and
that the main reason that we do not have any R level ALTREP API. If
you are interested in it you can find it from this issue:
https://github.com/Biocondu
I have found some weird SEXP corruption behavior with ALTREP, which
could be a bug. (Or I could be doing something wrong.)
I have an integer ALTREP vector that calls back to R from the Elt
method. When this vector is indexed in a lapply(), its first element
gets corrupted. Sometimes it's just a ty
