similar to: Object.size() should not visit every element for alt-rep strings, or there should be an altstring_objectsize_method

You should really take this up with RStudio. Calling object.size on every top level assignment as they appear to do is a bad idea, even without ALTREP. object.size is only a cheap operation for simple atomic vectors. For anything with recursive sturcture it needs to walk the object, so the effort is proprtional to object size: > x <- rep("A", 1e8) > system.time(object.size(x))

I have a toy alt-rep string package that generates randomly seeded strings. example: library(altstringisode) x <- altrandomStrings(1e8) head(x) [1] "2PN0bdwPY7CA8M06zVKEkhHgZVgtV1" "5PN2qmWqBlQ9wQj99nsQzldVI5ZuGX" ... etc object.size(1e8) Object.size will call the set_altstring_Elt_method for every single element, materializing (slowly) every element of the vector. This

On Mon, 21 Jan 2019, Martin Maechler wrote: >>>>>> Travers Ching >>>>>> on Tue, 15 Jan 2019 12:50:45 -0800 writes: > > > I have a toy alt-rep string package that generates > > randomly seeded strings. example: library(altstringisode) > > x <- altrandomStrings(1e8) head(x) [1] > >

On 1/22/19 6:17 PM, Kevin Ushey wrote: > I think that object.size() is most commonly used to answer the question, > "what R objects are consuming the most memory currently in my R session?" > and for that reason I think returning the size of the internal > representations of objects (for e.g. ALTREP objects; unevaluated promises) > is the right default behavior. I

Travers, Great to hear you're trying out the ALTREP stuff, good on you :). Did you mean the get_altstring_Elt_method? I see the code in size.c within utils that grabs each element, but I don't see any setting (and the setters are noops currently anyway they just do things the old way). One thing we have to decide is what object.size means for an altrep. I tend to think it should mean

>>>>> Travers Ching >>>>> on Tue, 15 Jan 2019 12:50:45 -0800 writes: > I have a toy alt-rep string package that generates > randomly seeded strings. example: library(altstringisode) > x <- altrandomStrings(1e8) head(x) [1] > "2PN0bdwPY7CA8M06zVKEkhHgZVgtV1" > "5PN2qmWqBlQ9wQj99nsQzldVI5ZuGX" ... etc

I think that object.size() is most commonly used to answer the question, "what R objects are consuming the most memory currently in my R session?" and for that reason I think returning the size of the internal representations of objects (for e.g. ALTREP objects; unevaluated promises) is the right default behavior. I also agree it would be worth considering adding arguments that control

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 Luke and Gabriel, Thank you very much for your quick responses. The explanation of STDVEC is very helpful and I appreciate it! For the wrapper, I have a few new questions. 1. Like Luke said a mutable object is not possible. However, I noticed that there is one extra argument *deep* in the function duplicate. I've googled all the available documentation for ALTREP but I did not find

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

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

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 devel team, I'm working on C/C++ level ALTREP compatibility for a package. The package previously used pointers to access the data of a SEXP, so it would not work for some ALTREP objects which do not have a pointer. I plan to rewrite the code and use functions like get_elt, get_region, and get_subset to access the values of a vector, so I have a few questions for ALTREP: 1. Since an

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 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

> 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

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 have two related ALTREP questions. It seems like there is no way to assign attributes to an ALTREP vector without using C++ code. To be more specifically, I want to make an ALTREP matrix, I have tried the following R code but none of them work. ``` .Internal(inspect(1:6)) .Internal(inspect(matrix(1:6, 2,3))) .Internal(inspect(as.matrix(1:6))) .Internal(inspect(structure(1:6, dim =

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

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