[Rd] [External] Re: Repeated library() of one package with different include.only= entries
Michael Chirico
m|ch@e|ch|r|co4 @end|ng |rom gm@||@com
Mon Apr 15 18:57:07 CEST 2024
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 <maechler using stat.math.ethz.ch>
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 <luke-tierney using 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
>
>
>
[[alternative HTML version deleted]]
More information about the R-devel
mailing list