search for: altstrings

A useful extension of ALTREP is having two new string methods which return the number of characters of a given string element and to return a substring of an element. Having these methods would allow retrieving these values without needing to create a CHARSXP for the full element data, which could potentially be costly for long elements. For example say you have an ALTREP altstring vector where

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

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

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 Kylie, As an alternative in the short term, you could consider deriving from S4Vector's List class, implementing the getListElement() method to lazily create the objects. Michael On Tue, Jul 23, 2019 at 9:09 AM Bemis, Kylie <k.bemis at northeastern.edu> wrote: > > Hello, > > I was wondering if there were any plans for ALTREP lists (VECSXP)? > > It seems to me that

Hi all, I'm wondering if there is any way to define a `SET_ELT` function for an ALTREP class? I see there are ` ALTINTEGER_SET_ELT` etc. functions exported in Rinternal.h, but there is no corresponding ALTREP APIs to define them. The only way to set the value of an ALTREP is through a pointer, which will require that the ALTREP data is in memory. Is it on purpose? Will there be any plan to

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

On Tue, 30 Jul 2019, Wang Jiefei wrote: > Hi all, > > I'm wondering if there is any way to define a `SET_ELT` function for an > ALTREP class? I see there are ` ALTINTEGER_SET_ELT` etc. functions exported > in Rinternal.h, but there is no corresponding ALTREP APIs to define them. > The only way to set the value of an ALTREP is through a pointer, which will > require that