[Rd] Coercion function does not work for the ALTREP object
Hi all, The coercion function defined for the ALTREP object will not be called by R when an assignment operation implicitly introduces coercion for a large ALTREP object. For example, If I create a vector of length 10, the ALTREP coercion function seems to work fine. ``` > x <- 1:10 > y <- wrap_altrep(x) > .Internal(inspect(y)) @0x1f9271c0 13 INTSXP g0c0 [REF(2)] I am altrep > y[1] <- 1.0 Duplicating object Coercing object > .Internal(inspect(y)) @0x1f927c08 14 REALSXP g0c0 [REF(1)] I am altrep ``` However, if I create a vector of length 1024, R will give me a normal real-type vector ``` > x <- 1:1024 > y <- wrap_altrep(x) > .Internal(inspect(y)) @0x1f8ddb20 13 INTSXP g0c0 [REF(2)] I am altrep > y[1] <- 1.0 > .Internal(inspect(y)) @0x1f0d72a0 14 REALSXP g0c7 [REF(1)] (len=1024, tl=0) 1,2,3,4,5,... ``` Note that the duplicate function is also called for the first example. It seems like R completely ignores my ALTREP functions in the second example. I feel this might be designed on purpose, but I do not understand the reason behind it. Is there any reason why we are not consistent here? Here is my session info sessionInfo() R Under development (unstable) (2020-09-03 r79126) Platform: x86_64-w64-mingw32/x64 (64-bit) Running under: Windows 10 x64 (build 18362) Best, Jiefei [[alternative HTML version deleted]] __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
Re: [Rd] Coercion function does not work for the ALTREP object
Jiefei, Where does the code for your altrep class live? Thanks, ~G On Wed, Oct 7, 2020 at 4:25 AM Jiefei Wang wrote: > Hi all, > > The coercion function defined for the ALTREP object will not be called by R > when an assignment operation implicitly introduces coercion for a large > ALTREP object. > > For example, If I create a vector of length 10, the ALTREP coercion > function seems to work fine. > ``` > > x <- 1:10 > > y <- wrap_altrep(x) > > .Internal(inspect(y)) > @0x1f9271c0 13 INTSXP g0c0 [REF(2)] I am altrep > > y[1] <- 1.0 > Duplicating object > Coercing object > > .Internal(inspect(y)) > @0x1f927c08 14 REALSXP g0c0 [REF(1)] I am altrep > ``` > > However, if I create a vector of length 1024, R will give me a normal > real-type vector > ``` > > x <- 1:1024 > > y <- wrap_altrep(x) > > .Internal(inspect(y)) > @0x1f8ddb20 13 INTSXP g0c0 [REF(2)] I am altrep > > y[1] <- 1.0 > > .Internal(inspect(y)) > @0x1f0d72a0 14 REALSXP g0c7 [REF(1)] (len=1024, tl=0) 1,2,3,4,5,... > ``` > > Note that the duplicate function is also called for the first example. It > seems like R completely ignores my ALTREP functions in the second example. > I feel this might be designed on purpose, but I do not understand the > reason behind it. Is there any reason why we are not consistent here? Here > is my session info > > sessionInfo() > R Under development (unstable) (2020-09-03 r79126) > Platform: x86_64-w64-mingw32/x64 (64-bit) > Running under: Windows 10 x64 (build 18362) > > Best, > Jiefei > > [[alternative HTML version deleted]] > > __ > 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
Re: [Rd] Coercion function does not work for the ALTREP object
Hi Gabriel, here is a simple package for reproducing the problem. https://github.com/Jiefei-Wang/testPkg Best, Jiefei On Thu, Oct 8, 2020 at 5:04 AM Gabriel Becker wrote: > Jiefei, > > Where does the code for your altrep class live? > > Thanks, > ~G > > On Wed, Oct 7, 2020 at 4:25 AM Jiefei Wang wrote: > >> Hi all, >> >> The coercion function defined for the ALTREP object will not be called by >> R >> when an assignment operation implicitly introduces coercion for a large >> ALTREP object. >> >> For example, If I create a vector of length 10, the ALTREP coercion >> function seems to work fine. >> ``` >> > x <- 1:10 >> > y <- wrap_altrep(x) >> > .Internal(inspect(y)) >> @0x1f9271c0 13 INTSXP g0c0 [REF(2)] I am altrep >> > y[1] <- 1.0 >> Duplicating object >> Coercing object >> > .Internal(inspect(y)) >> @0x1f927c08 14 REALSXP g0c0 [REF(1)] I am altrep >> ``` >> >> However, if I create a vector of length 1024, R will give me a normal >> real-type vector >> ``` >> > x <- 1:1024 >> > y <- wrap_altrep(x) >> > .Internal(inspect(y)) >> @0x1f8ddb20 13 INTSXP g0c0 [REF(2)] I am altrep >> > y[1] <- 1.0 >> > .Internal(inspect(y)) >> @0x1f0d72a0 14 REALSXP g0c7 [REF(1)] (len=1024, tl=0) >> 1,2,3,4,5,... >> ``` >> >> Note that the duplicate function is also called for the first example. It >> seems like R completely ignores my ALTREP functions in the second example. >> I feel this might be designed on purpose, but I do not understand the >> reason behind it. Is there any reason why we are not consistent here? Here >> is my session info >> >> sessionInfo() >> R Under development (unstable) (2020-09-03 r79126) >> Platform: x86_64-w64-mingw32/x64 (64-bit) >> Running under: Windows 10 x64 (build 18362) >> >> Best, >> Jiefei >> >> [[alternative HTML version deleted]] >> >> __ >> 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
