From murdoch.duncan at gmail.com  Sun Jun 29 21:43:01 2014
From: murdoch.duncan at gmail.com (Duncan Murdoch)
Date: Sun, 29 Jun 2014 21:43:01 +0200
Subject: [Rd] R CMD check warning with S3 method
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Message-ID: <53B06C45.30208@gmail.com>

On 29/06/2014, 3:07 PM, Michael Lawrence wrote:
> While the change to the symbol lookup is generally useful (e.g., for
> finding S4 methods that become available whenever a package is loaded),
> it seems that we ultimately want a mechanism by which a package
> namespace can formally declare that it is re-exporting a symbol from
> some package. Then, for example, the check mechanism can be made smart
> enough to avoid throwing such warnings.
> 
> I've developed a proof-of-concept exportFrom() namespace directive. This
> is the syntax:
> 
> exportFrom(utils, help)
> 
> Then:
> 
>> getNamespaceInfo("ReexportingPackage", "exports")$help
> [1] "help"
> attr(,"origin")
> [1] "utils"
> 
> Comments?

I don't see why this is needed.  What does it gain over documenting that
the symbol "help" is just a copy of the one from utils?  As of this
morning, that's easy...

Duncan Murdoch

> 
> Michael
> 
> 
> On Fri, Jun 27, 2014 at 8:32 PM, Yihui Xie <xie at yihui.name
> <mailto:xie at yihui.name>> wrote:
> 
>     Hi Duncan,
> 
>     Again, thanks a lot for making this change (help requests are tried
>     over all loaded instead of attached packages):
>     https://github.com/wch/r-source/commit/21d2f7430b4 This makes what I
>     proposed last time possible now: if pkg B imports FUN from A and
>     re-exports it, ?FUN will work after B is attached because A will also
>     be at least attached.
> 
>     Then it will be perfect if `R CMD check` can stop warning against the
>     missing documentation, which is not really missing.
> 
>     Regards,
>     Yihui
>     --
>     Yihui Xie <xieyihui at gmail.com <mailto:xieyihui at gmail.com>>
>     Web: http://yihui.name
> 
> 
>     On Fri, Jun 20, 2014 at 1:34 AM, Yihui Xie <xie at yihui.name
>     <mailto:xie at yihui.name>> wrote:
>     > but note that you will have to document it even if it is a function
>     > imported from another package... Perhaps help() should be intelligent
>     > enough to link the documentation of `FUN` from package A for package B
>     > when B imports `FUN` from A, and exports it in B's NAMESPACE. The
>     > package name of A may be obtained from
>     > environmentName(environment(FUN)). At the moment, since R CMD check
>     > will warn against the missing documentation of `FUN` in B, I have to
>     > copy FUN.Rd from A to B in this case, which seems to be inefficient
>     > and not a best way to maintain. Did I miss anything in the R-exts
>     > manual?
>     >
>     > Regards,
>     > Yihui
>     > --
>     > Yihui Xie <xieyihui at gmail.com <mailto:xieyihui at gmail.com>>
>     > Web: http://yihui.name
>     >
>     >
>     > On Fri, Jun 20, 2014 at 12:19 AM, Winston Chang
>     <winstonchang1 at gmail.com <mailto:winstonchang1 at gmail.com>> wrote:
>     >> On Thu, Jun 19, 2014 at 3:15 PM, Martyn Plummer <plummerm at iarc.fr
>     <mailto:plummerm at iarc.fr>> wrote:
>     >>
>     >>>  Export filter in the NAMESPACE file *without copying it* in the
>     R source
>     >>> code.
>     >>>
>     >>>
>     >> Ah, it works! Thank you!
>     >>
> 
>     ______________________________________________
>     R-devel at r-project.org <mailto:R-devel at r-project.org> mailing list
>     https://stat.ethz.ch/mailman/listinfo/r-devel
> 
>



[Rd] R CMD check warning with S3 method
Duncan Murdoch