> 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. > 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. > ?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): 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. On Thu, Apr 11, 2024 at 7:37 AM <luke-tier...@uiowa.edu> 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 > > > > ______________________________________________ > > R-devel@r-project.org mailing list > > https://stat.ethz.ch/mailman/listinfo/r-devel > > > > -- > Luke Tierney > Ralph E. Wareham Professor of Mathematical Sciences > University of Iowa Phone: 319-335-3386 > Department of Statistics and Fax: 319-335-3017 > Actuarial Science > 241 Schaeffer Hall email: luke-tier...@uiowa.edu > Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu/ [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel