From ligges at statistik.tu-dortmund.de  Thu Aug 28 00:25:10 2014
From: ligges at statistik.tu-dortmund.de (Uwe Ligges)
Date: Thu, 28 Aug 2014 00:25:10 +0200
Subject: [Rd] Re R CMD check checking in development version of R
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On 28.08.2014 00:19, Gavin Simpson wrote:
> On 27 August 2014 16:09, Dan Tenenbaum <dtenenba at fhcrc.org> wrote:
>
>> ----- Original Message -----
>>> From: "Gavin Simpson" <ucfagls at gmail.com>
>>> To: "Hadley Wickham" <h.wickham at gmail.com>
>>> Cc: r-devel at r-project.org
>>> Sent: Wednesday, August 27, 2014 3:01:53 PM
>>> Subject: Re: [Rd] Re R CMD check checking in development version of R
>>>
>>> On 27 August 2014 15:24, Hadley Wickham <h.wickham at gmail.com> wrote:
>>>
>>>>> Is that the cause of these NOTEs? Is the expectation that if I am
>>>>> using a
>>>>> function from a package, even a package that I have in Depends:,
>>>>> that I
>>>>> have to explicitly declare these imports in NAMESPACE?
>>>>
>>>> Yes.
>>
>
>
>>>> (And really you shouldn't have any packages in depends, they should
>>>> all be in imports)
>>>
>>>
>>> I disagree with *any*; having say vegan loaded when one is using
>>> analogue
>>> is a design decision as the latter borrows heavily from and builds
>>> upon
>>> vegan. In general I have moved packages that didn't need to be in
>>> Depends
>>> into Imports; in the version I am currently doing final tweaks on
>>> before it
>>> goes to CRAN I have remove all but vegan from Depends.
>>>
>>> Or am I thinking about this in the wrong way?
>>>
>>
>> I've found that if yourpkg (which Depends on theirpkg but does not import
>> it) has yourfunction() which calls some function in theirpkg, and if
>> someone else writes a package which imports yourpkg and calls yourfunction,
>> it will not work. Whereas if yourpkg imported theirpkg (in the NAMESPACE
>> file), it would work. I've had to write to many package maintainers asking
>> them to import things for this reason.
>>
>> So that in itself is a reason not to use Depends, or at least, to be sure
>> that you import (in your NAMESPACE) whatever's in Depends (in addition to
>> Imports).
>>
>> Dan
>
>
> Dan,
>
> I think we'll just have to differ on this point Dan. Why should I make it
> somewhat more complicated for the people I anticipate using my package just
> so that I make it easier for developers of other packages to *potentially*
> write code using my packages. analogue and vegan have been around for a
> long time, since before the required namespaces --- in vegan's case
> possibly before there were namespaces in R (or at least before the were in
> widespread use), so to change the standard behaviour of loading my package
> and getting vegan too is not something I'm going to do lightly. Especially
> as there are several papers out there with code written before the
> compulsory namespace stuff came to R that assumed vegan was loaded because
> thats what `library("analogue")` *did*.
>
> I'm happy to work with developers on issues as they arrive of course. I
> just don;t see why their envisioned future needs should trump the needs of
> the user now.
>
> If we take your and Hadley's reasoning to the extreme, not a single package
> should use Depends in which case what purpose is there for Depends? Until R
> Core remove Depends from DESCRIPTION and flag it under `R CMD check`-ing
> people, including me, are going to continue using it if that is what they
> think is best for their users.
>
> Again, I am happy to be re-educated on this though :-)

If you like, you can fill the search path with lots of packages (and 
make masking of functions more likely), but you shoudl really import 
into your namesoace so that unanticipated order of packages in your 
search path won't break your package.

Best,
Uwe Ligges



[Rd] Re R CMD check checking in development version of R
Uwe Ligges