Thank Denes for the clarification, glad to see my package got one citation from my own question:) Also, thank Benjamin for sending many useful documents.
Actually, the question is related to the SharedObject package that Benjamin has pointed to. I wanna avoid sharing an object that has already been shared, so I need to check whether an object is an ALTREP that is defined in my package. Since the ALTREP definition involves an ` R_altrep_class_t` object and a class name, I will expect to see a method defined in R to retrieve such information. I hope this can clarify my question. Best, Jiefei On Mon, Oct 19, 2020 at 5:38 PM Benjamin Christoffersen <boenn...@gmail.com> wrote: > > You happened to send a link which points to the OP's own package :) I > > think Jiefei would like to know how one can "officially" determine if an > > arbitrary ALTERP object belongs to a class that he owns. > Argh, I am sorry! I did not notice that. My best bet for what I > thought the question was is section 1.1.2 of R Internals where they > note that: `unsigned int alt : 1; /* is this an ALTREP object? */` > > This is also what the ALTREP macro checks. However, I also did not > notice the "... if an ALTREP object is from my package" part. I am > sorry. > > Sincerely Yours, > Benjamin > > Den man. 19. okt. 2020 kl. 11.25 skrev Dénes Tóth <toth.de...@kogentum.hu > >: > > > > Benjamin, > > > > You happened to send a link which points to the OP's own package :) I > > think Jiefei would like to know how one can "officially" determine if an > > arbitrary ALTERP object belongs to a class that he owns. > > > > Regards, > > Denes > > > > > > On 10/19/20 10:22 AM, Benjamin Christoffersen wrote: > > > It seems as if you can you use the ALTREP macro as done in this > > > package: > https://github.com/Jiefei-Wang/SharedObject/blob/804b6ac58c63a4bae95343ab43e8b1547b07ee6b/src/C_interface.cpp#L185 > > > > > > and in base R: > https://github.com/wch/r-source/blob/54fbdca9d3fc63437d9e697f442d32732fb4f443/src/include/Rinlinedfuns.h#L118 > > > > > > The macro is defined here in Rinternals.h: > > > > https://github.com/wch/r-source/blob/abb550c99b3927e5fc03d12f1a8e7593fddc04d2/src/include/Rinternals.h#L325 > > > > > > Den man. 19. okt. 2020 kl. 10.13 skrev Jiefei Wang <szwj...@gmail.com > >: > > >> > > >> Hi all, > > >> > > >> I would like to determine if an ALTREP object is from my package, I > see > > >> there is a function `ALTREP_CLASS` defined in RInternal.h but its > return > > >> value is neither a `R_altrep_class_t` object nor an STRSXP > representing a > > >> class name. I do not know how to correctly use it. Any suggestions? > > >> > > >> Thanks, > > >> Jiefei > > >> > > >> [[alternative HTML version deleted]] > > >> > > >> ______________________________________________ > > >> R-devel@r-project.org mailing list > > >> https://stat.ethz.ch/mailman/listinfo/r-devel > > > > > > ______________________________________________ > > > R-devel@r-project.org mailing list > > > https://stat.ethz.ch/mailman/listinfo/r-devel > > > > [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel