similar to: ALTREP "wrapper" classes needs an Extract_subset method

I can work on this. Thanks Luke. ~G On Wed, Jul 24, 2019 at 8:25 AM Tierney, Luke <luke-tierney at uiowa.edu> wrote: > If one of you wanted to try to create a patch to support ALTREP > generic vectors here are some notes: > > The main challenge I am aware of (there might be others): Allowing > DATAPTR to return a writable pointer would be too dangerous because > the GC

Hi Bob, Thanks for sending around the link to that. It looks mostly right and looks like a useful onramp. There are a few things to watch out for though (I've cc'ed Romain so he's aware of these comments). @romain I hope you taake the following comments as they are intended, as help rather than attacks. The largest issue I see is that the contract for Get_region is that it *populates

Hi Kylie, Is it a list with only numerics in it? (I only see REALSXPs there, but obviously inspect isn't showing all of them). If so, you could load it up into one big vector and then also keep partitioning information around. Bioconductor does this (see ?IRanges::CompressedList ). The potential benefit here being that the underlying large vector could then be a big out-of-memory altrep. How

Sorry for post a lot of things, for the first part of code, I copied my C++ iter macro by mistake(and you can see an explicit type casting). Here is the macro definition from R_exts/Itermacros.h #define ITERATE_BY_REGION_PARTIAL(sx, px, idx, nb, etype, vtype, \ strt, nfull, expr) do { \ * const** etype *px = DATAPTR_OR_NULL(sx); *

If one of you wanted to try to create a patch to support ALTREP generic vectors here are some notes: The main challenge I am aware of (there might be others): Allowing DATAPTR to return a writable pointer would be too dangerous because the GC write barrier needs to see all mutations. So it would be best if Dataptr and Dataptr_or_null methods were not allowed to be defined. The default methods in

Thanks, Hernando, Sorry, "API" is a bit confusing term in this context, but what I want to discuss is the "API" that Writing R Extension defines as quoted in my previous email. It's probably different from an ordinary sense when we casually say "R C API". You might wonder why I care about such a difference. This is because calling a "non-API" is

Hello, I don't believe it is illegal, as ALTREP "implements an abstraction underneath the C API". And is "compatible with all code which uses the API". Please see slide deck by Gabriel Becker, with L Tierney, M Lawrence and T Kalibera. https://bioconductor.org/help/course-materials/2020/BiocDevelForum/16-ALTREP .pdf ALTREP framework implements an abstraction underneath

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)) @0x000000001f9271c0 13 INTSXP g0c0 [REF(2)] I am

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 <gabembecker at gmail.com> wrote: > Jiefei, > > Where does the code for your altrep class live? > > Thanks, > ~G > > On Wed, Oct 7, 2020 at 4:25 AM Jiefei Wang <szwjf08 at gmail.com> wrote: >

Writing R Extension[1] defines "API" as: Entry points which are documented in this manual and declared in an installed header file. These can be used in distributed packages and will only be changed after deprecation. But, the document (WRE) doesn't have even a single mention of ALTREP, the term "ALTREP" itself or any entry points related to ALTREP. Does this mean,

Thanks for your convincing comment, but it seems the R core team has a different opinion... A few hours ago, src/include/R_ext/Altrep.h got this comment: /* Not part of the API, subject to change at any time. */ commit: https://github.com/r-devel/r-svn/commit/2059bffde642f8426d1f39ab5dd995d19a575d4d While I'm glad to see their attempt to make it clear, I'm confused. That

> On Apr 22, 2024, at 7:37 PM, Gabriel Becker <gabembecker at gmail.com> wrote: > > Hi Yutani, > > ALTREP is part of the official R api, as illustrated by the presence of > src/include/R_ext/Altrep.h. Everything declared in the header files in that > directory is official API AFAIK (and I believe that is more definitive than > the manuals). > That is not true

Hi Yutani, ALTREP is part of the official R api, as illustrated by the presence of src/include/R_ext/Altrep.h. Everything declared in the header files in that directory is official API AFAIK (and I believe that is more definitive than the manuals). The documentation of ALTREP has lagged behind its implementation unfortunately, which may partially my fault for not submitting doc patches for it

Hi, By looking at a doc about ALTREP https://svn.r-project.org/R/branches/ALTREP/ALTREP.html (by the way congratulations for that and for R-3.5.0 in general), I was a little bit surprised by the following example: > x <- 1:1e10 > system.time(print(mean(x))) [1] 5e+09 ?? user? system elapsed ?38.520?? 0.008? 38.531 Taking 38.520 s to calculate a mean value of an arithmetic

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

Hello, I'm developing a package (lazyvec) that makes full use of the ALTREP framework (R >= 3.6.0). One application of the package is to wrap existing ALTREP vectors in a new ALTREP vector and pass all calls from R to the contained object. The purpose of this is to provide a diagnostic framework for working with ALTREP vectors and show information about internal calls. The package builds

Hi Gabriel, thanks for your detailed explanation, that definitely clarifies the design choices that were made in setting up the ALTREP framework and I can see how those choices make sure existing code won't break. My specific use-case for wanting to check whether a vector is an ALTREP is the following: the fst package wraps an external C++ library (fstlib, independent from R) that was made

thanks for clearing that up, so these methods are actually not meant to be exported on Windows and OSX? Some of the ALTREP methods that now use 'attribute_hidden' would be very useful to packages that aim to be ALTREP aware, should the currently (exported) API be considered final? thanks for your time & best, Mark On Tue, Jun 4, 2019 at 6:52 PM Tierney, Luke <luke-tierney at

Hello, I have encountered two bugs when using ALTREP APIs. 1. STDVEC_DATAPTR >From RInternal.h file it has a comment: /* ALTREP support */ > void *(STDVEC_DATAPTR)(SEXP x); However, this comment might not be true, the easiest way to verify it is to define a C++ function: void C_testFunc(SEXP a) > { > STDVEC_DATAPTR(a); > } and call it in R via > a=1:10 > >

Hello, I was wondering if there were any plans for ALTREP lists (VECSXP)? It seems to me that they could be supported in a similar way to how ALTSTRING works, with Elt() and Set_elt() methods, or would there be some problems with that I?m not seeing due to lists not being atomic vectors? I was taking an approach of converting each list element (of a file-based list data structure) to an ALTREP