Happily, package parallel is open-source. If you would like to make use of the unexported functions, you could copy the source code with acknowledgement into your package. Naturally this might be a lot of work and risks different behaviour between your package and parallel, but neither might be that terrible for you. And certainly would be better than trying to pretend that the functions you want are exported from parallel.
On Fri, 23 Jul 2021 at 23:09, David Norris <da...@precisionmethods.guru> wrote: > > I can confirm that getFromNamespace() does indeed circumvent the WARNING. > I might otherwise prefer ':::', however, for making its 'bad intentions' so > clear. > I was very much aware of the cautionary language under `?readChild`, but > wondered whether *in practice* more liberal community policies might be in > force pending the maturation of the futureverse. > Although the sparse history of the relevant file hardly supports > "might-break-at-any-time" alarmism, I do note that the last commit (in May > 2020) introduced an argument sendMaster(raw.asis=TRUE) that I am actually > using. > https://github.com/wch/r-source/commits/trunk/src/library/parallel/R/unix/mcfork.R > > (Also agree with Yohann that ideally one might support Windows with a warning > such as data.table issues regarding my Mac's non-support for OpenMP.) > > Best, David > > From: Sebastian Meyer <seb.me...@fau.de> > Organization: Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) > Date: Friday, July 23, 2021 at 8:05 AM > To: David Norris <da...@precisionmethods.guru>, > "r-package-devel@r-project.org" <r-package-devel@r-project.org> > Subject: Re: [R-pkg-devel] Using parallel:::sendMaster &c. despite warnings > > Am 23.07.21 um 13:19 schrieb David Norris: > Because parallelized progress reporting in the futureverse.org incurs > latencies too great for my application > (https://github.com/HenrikBengtsson/progressr/issues/118), I have found it > necessary to implement my own progress reporting using some of the > non-exported functionality from `parallel`. (I do appreciate that Windows > lacks the fork() system call, and will not support this. But am willing to > make this an OS_type: unix-only package.) > > Of course, I get a WARNING for this: > > ── R CMD check results ──────────────────────────────── precautionary 0.2.6 > ──── > Duration: 6m 41.8s > > ❯ checking dependencies in R code ... WARNING > Unexported objects imported by ':::' calls: > ‘parallel:::readChild’ ‘parallel:::selectChildren’ > ‘parallel:::sendMaster’ > See the note in ?`:::` about the use of this operator. > Including base/recommended package(s): > ‘parallel’ > > Is this warning an absolute deal-killer on CRAN? Is there a 'correct' way to > do `:::` that avoids the warning altogether? > > The 'parallel' functions your package intends to access seem to be > intentionally unexported. Their help page says: "They are not available > on Windows, and not exported from the namespace", and "This is a very > low-level interface for expert use only: it not regarded as part of the > R API and subject to change without notice." > > Correspondingly, the CRAN Repository Policy says > > Also, ::: should not be used to access undocumented/internal objects in base > packages (nor should other means of access be employed). Such usages can > cause packages to break at any time, even in patched versions of R. > > which kind of answers both of your questions. The policy thus implicitly > advises against using getFromNamespace(). > > Best regards, > > Sebastian Meyer > > > Kind regards, > David Norris > > ______________________________________________ > mailto:R-package-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-package-devel > > > > ______________________________________________ > R-package-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-package-devel ______________________________________________ R-package-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-package-devel
