OK, I've moved your suggestions into the tracker for further discussion: https://bugs.r-project.org/show_bug.cgi?id=18703 https://bugs.r-project.org/show_bug.cgi?id=18704 https://bugs.r-project.org/show_bug.cgi?id=18705
I will tackle a patch for 18705 to start with as the lowest-hanging fruit. On Mon, Apr 15, 2024 at 6:46 AM Martin Maechler <[email protected]> wrote: > I think we should try to advance and hopefully finalize this > thread before we forget about it .. > > >>>>> Michael Chirico n Thu, 11 Apr 2024 09:10:11 -0700 writes: > > >> I would assume that > > >> library(Matrix, include.only="isDiagonal") > > >> implies that only `isDiagonal` ends up on the search path > > > This could also be a reasonable behavior, but neither does that > happen > > today. > > Indeed; I think we should signal a warning at least in the case > it does not happen --- namely when "parts of Matrix" are already > in the search path. > > >> I think a far better approach to solve Michael's problem is simply > to use > > >> fac2sparse <- Matrix::fac2sparse > > > This does not fully simulate attachment, e.g. running package hooks & > > resolving Depends. > > (indeed; as library() is really about search() patch attchment) > > >> ?library could also mention using detach() followed by library() or > >> attachNamespace() with a new include.only specification. > > > This is the "quite hard to accomplish" I alluded to, admittedly I > hadn't > > forced myself to write it all out -- maybe it's not as bad as all > that. > > After some iterations, today I think we'd want to do... > > > modify_attach <- function(pkg, new_names) { > > if (!startsWith(pkg, "package:")) pkg <- paste0("package:", pkg) > > old <- tryCatch(ls(pkg, all.names=TRUE), error=\(c) character()) > > if (length(old)) detach(pkg) > > attachNamespace(.rmpkg(pkg), include.only=c(new_names, old)) > > } > > > Perhaps detach() could invisibly return the exported names to make > this a > > tiny bit easier (today it returns NULL): > > I agree that such changed detach() behavior would be "nice" here; > but I wouldn't like to change its default behavior, notably as > in 99.5% of its use, the names would not be used. > I'd agree to add a new option for detach() to return the names > (visibly in that case). > > > modify_attach <- function(pkg, new_names) { > > if (!startsWith(pkg, "package:")) pkg <- paste0("package:", pkg) > > old <- tryCatch(detach(pkg), error=\(c) character()) > > attachNamespace(.rmpkg(pkg), include.only=c(new_names, old)) > > } > > > Regardless, I think your suggestion to just point to > > detach()+attachNamespace() is reasonable enough, the rare users that > care > > about this are likely to be able to figure out the rest from there. > > So I think we agree here; mentioning such a modify_attach() > ... I'd use an example *without* tryCatch() as I think the user > should choose their own line of action in such cases > ... > on the help page would then be appropriate. > > Martin > > > On Thu, Apr 11, 2024 at 7:37 AM <[email protected]> wrote: > > >> On Thu, 11 Apr 2024, Duncan Murdoch wrote: > >> > >> > On 11/04/2024 7:04 a.m., Martin Maechler wrote: > >> >>>>>>> Michael Chirico > >> >>>>>>> on Mon, 8 Apr 2024 10:19:29 -0700 writes: > >> >> > >> >> > Right now, attaching the same package with different > >> include.only= has no effect: > >> >> > >> >> > library(Matrix, include.only="fac2sparse") > >> >> > library(Matrix) > >> >> > ls("package:Matrix") > >> >> > # [1] "fac2sparse" > >> >> > >> >> > ?library does not cover this case -- what is covered is > the _loading_ > >> >> > behavior of repeated calls: > >> >> > >> >> >> [library and require] check and update the list of > currently attached > >> >> > packages and do not reload a namespace which is already > loaded > >> >> > >> >> > But here we're looking at the _attach_ behavior of > repeated calls. > >> >> > >> >> > I am particularly interested in allowing the exports of a > >> package to be > >> >> > built up gradually: > >> >> > >> >> > library(Matrix, include.only="fac2sparse") > >> >> > library(Matrix, include.only="isDiagonal") # > want:ls("package:Matrix") --> > >> >> > c("fac2sparse", "isDiagonal") > >> >> > ... > >> >> > >> >> > It seems quite hard to accomplish this at the moment. Is > the behavior to > >> >> > ignore new inclusions intentional? Could there be an > argument to get > >> >> > different behavior? > >> >> > >> >> As you did not get an answer yet, ..., some remarks by an > >> >> R-corer who has tweaked library() behavior in the past : > >> >> > >> >> - The `include.only = *` argument to library() has been a > >> >> *relatively* recent addition {given the 25+ years of R > history}: > >> >> > >> >> It was part of the extensive new features by Luke Tierney for > >> >> R 3.6.0 [r76248 | luke | 2019-03-18 17:29:35 +0100], with > NEWS entry > >> >> > >> >> • library() and require() now allow more control over > handling > >> >> search path conflicts when packages are attached. The > policy is > >> >> controlled by the new conflicts.policy option. > >> >> > >> >> - I haven't seen these (then) new features been used much, > unfortunately, > >> >> also not from R-core members, but I'd be happy to > >> >> be told a different story. > >> >> > >> >> For the above reasons, it could well be that the current > >> >> implementation {of these features} has not been exercised a lot > >> >> yet, and limitations as you found them haven't been noticed yet, > >> >> or at least not noticed on the public R mailing lists, nor > >> >> otherwise by R-core (?). > >> >> > >> >> Your implicitly proposed new feature (or even *changed* > >> >> default behavior) seems to make sense to me -- but as alluded > >> >> to, above, I haven't been a conscious user of any > >> >> 'library(.., include.only = *)' till now. > >> > > >> > I don't think it makes sense. I would assume that > >> > > >> > library(Matrix, include.only="isDiagonal") > >> > > >> > implies that only `isDiagonal` ends up on the search path, i.e. > >> > "include.only" means "include only", not "include in addition to > whatever > >> > else has already been attached". > >> > > >> > I think a far better approach to solve Michael's problem is > simply to use > >> > > >> > fac2sparse <- Matrix::fac2sparse > >> > isDiagonal <- Matrix::isDiagonal > >> > > >> > instead of messing around with the user's search list, which may > have been > >> > intentionally set to include only one of those. > >> > > >> > So I'd suggest changing the docs to say > >> > > >> > "[library and require] check and update the list of currently > attached > >> > packages and do not reload a namespace which is already loaded. > >> > If a package is already attached, no change will be made." > >> > >> ?library could also mention using detach() followed by library() or > >> attachNamespace() with a new include.only specification. > >> > >> Best, > >> > >> luke > >> > >> > > >> > Duncan Murdoch > > > [[alternative HTML version deleted]] ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
