[R-pkg-devel] if statements in NAMESPACE file

[Andrew Simmons]

You are correct, it most definitely is a convoluted way to identify a path,
but this is one incredibly specific scenario. The case I'm talking about
only occurs when running a script in Rgui for Windows using Ctrl+R (or
pasting into the R Console) to run a piece of code. Scenarios such as
running from the Windows command-line / / Unix terminal / / using source,
sys.source, RStudio's debugSource, and testthat::source_file are handled in
a much different and less convoluted manner.
And in this case, the window handle relevant to the script has to exist,
otherwise you couldn't open the script in Rgui in the first place. I'm not
disagreeing that it's a horrible way to retrieve the path of the executing
script, but it's the only way if you're running from an open script in Rgui
for Windows.

On Thu, Sep 30, 2021 at 5:53 PM Jeff Newmiller <jdnewmil using dcn.davis.ca.us>
wrote:

> Expecting a window handle relevant to the script to exist for the purpose
> of identifying a path seem to be orthogonal problems to me. But Andrew has
> indicated offlist that he has alternate code for other cases only uses this
> technique when appropriate.
>
> I still feel this is too convoluted as a way to identify a path, but if he
> covers all cases then my opinion is just an opinion.
>
> On September 30, 2021 2:34:48 PM PDT, Duncan Murdoch <
> murdoch.duncan using gmail.com> wrote:
> >On 30/09/2021 5:21 p.m., Jeff Newmiller wrote:
> >> What if you are on Windows but running R at the command prompt, or via
> cygwin, or in the console window of RStudio?
> >>
> >> This seems unstable to me.
> >
> >Sorry, too much context missing.  What's unstable?
> >
> >Duncan Murdoch
> >
> >>
> >> On September 30, 2021 11:52:16 AM PDT, Andrew Simmons <
> akwsimmo using gmail.com> wrote:
> >>> Hello,
> >>>
> >>>
> >>> I'm updating my package 'this.path' which is supposed to retrieve the
> >>> absolute path of the executing script when called. It's similar to
> 'here',
> >>> except that 'here' constructs paths relative to a project directory,
> >>> whereas 'this.path' constructs paths relative to script directories. I
> was
> >>> updating the section where I retrieve the executing script's path while
> >>> running from a script open in Rgui for Windows, and I needed
> >>> utils::getWindowsHandles to do such a thing. But
> utils::getWindowsHandles
> >>> is a Windows only function, I
> >>> would imagine that 'utils' contains a similar line of code as above:
> >>>
> >>>
> >>> if (.Platform$OS.type == "windows")
> >>>     getWindowsHandles <- function() ...
> >>>
> >>>
> >>> and then in the NAMESPACE:
> >>>
> >>>
> >>> if (.Platform$OS.type == "windows")
> >>>     export(getWindowsHandles)
> >>>
> >>>
> >>> so I'd like to change my code to getWindowsHandles and import
> >>> getWindowsHandles from utils, but I can only do that on Windows, and
> so the
> >>> conditional importing should work for me. At no point does my function
> >>> mis-behave because of a attempting to use a function that isn't
> exported on
> >>> that platform, because within the function it only uses
> getWindowsHandles
> >>> if the OS is Windows.
> >>>
> >>>
> >>> On Thu, Sep 30, 2021 at 11:01 AM Mark Miller <
> mark.roman.miller using gmail.com>
> >>> wrote:
> >>>
> >>>> Returning to the original question, if it's helpful: I'd like to know
> what
> >>>> constraints led to considering an export only available on Windows,
> and see
> >>>> if we can suggest some other designs. It'd be good to keep the user's
> >>>> mental model abstracted from the platform they're working on. There
> are
> >>>> often unavoidable differences due to platform, but usually they're
> handled
> >>>> with warnings and errors rather than selective exports.
> >>>>
> >>>> On Thu, Sep 30, 2021 at 3:40 AM Berry Boessenkool <
> >>>> berryboessenkool using hotmail.com> wrote:
> >>>>
> >>>>>
> >>>>> One of the very best fortunes nominations!
> >>>>>
> >>>>> [...]
> >>>>>
> >>>>>    I suspect something like
> >>>>>
> >>>>>     if (stats::runif(1) > 0.5) export(someFunction)
> >>>>>
> >>>>> would work too, for a particularly frustrating experience for your
> >>>>> users.  It would mean half the installs export the function, and half
> >>>>> don't.
> >>>>>
> >>>>> Duncan Murdoch
> >>>>>
> >>>>>
> >>>>>          [[alternative HTML version deleted]]
> >>>>>
> >>>>> ______________________________________________
> >>>>> R-package-devel using r-project.org mailing list
> >>>>> https://stat.ethz.ch/mailman/listinfo/r-package-devel
> >>>>>
> >>>>
> >>>>          [[alternative HTML version deleted]]
> >>>>
> >>>> ______________________________________________
> >>>> R-package-devel using r-project.org mailing list
> >>>> https://stat.ethz.ch/mailman/listinfo/r-package-devel
> >>>>
> >>>
> >>>     [[alternative HTML version deleted]]
> >>>
> >>> ______________________________________________
> >>> R-package-devel using r-project.org mailing list
> >>> https://stat.ethz.ch/mailman/listinfo/r-package-devel
> >>
> >
>
> --
> Sent from my phone. Please excuse my brevity.
>

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