From friendly at yorku.ca  Thu Aug 22 20:57:25 2013
From: friendly at yorku.ca (Michael Friendly)
Date: Thu, 22 Aug 2013 14:57:25 -0400
Subject: [Rd] legitimate use of :::
In-Reply-To: <5215F9BD.5030009@statistik.tu-dortmund.de>
References: <CANROs4dyoRyjoVHZLs7wDrFrjVX-1zvTTv2i4tBzF3f6Rx-XTA@mail.gmail.com>
	<5215F9BD.5030009@statistik.tu-dortmund.de>
Message-ID: <52165F15.1090500@yorku.ca>

On 8/22/2013 7:45 AM, Uwe Ligges wrote:
>
>
> On 22.08.2013 07:45, Yihui Xie wrote:
>> Hi,
>>
>> So now R CMD check starts to warn against :::, but I believe sometimes
>> it is legitimate to use it when developing R packages. For example, I
>> have some utils functions that are not exported but I want to share
>> them across the packages that I maintain. I do not need to coordinate
>> with other authors about these internal functions since I'm the only
>> author and I know clearly what I'm doing, and I want to avoid copying
>> and pasting the code across packages just to avoid the NOTE in R CMD
>> check. What should I do in this case?
>
> Nothing. The way you describe above seems to be a reasonable usage, iff
> you are the same maintainer who knows what is going on. Other
> maintainers should not use one of your not exported (hence non API)
> functions, of course.
>
> Uwe Ligges
>
>

Related to this is the use of other-package unexported utility functions 
that don't pass Uwe's iff test, but I, as maintainer,
want to use in my package.

Cases in point:  in heplots, I had used stats:::Pillai, stats:::Wilks,
stats:::Roy and stats:::LH for calculation in one of my functions.
Similarly, I had a need to use car:::df.terms, also unexported, but
don't want to ask John Fox to export it just for my use.  Uwe's
reply suggests that I should not be using car:::df.terms, however.

To avoid the NOTEs (which often triggers a 'pls fix' upon submission to
CRAN), I simply copied/pasted these functions to my package, but this 
seems wasteful.

-Michael


-- 
Michael Friendly     Email: friendly AT yorku DOT ca
Professor, Psychology Dept. & Chair, Quantitative Methods
York University      Voice: 416 736-2100 x66249 Fax: 416 736-5814
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[Rd] legitimate use of :::
Michael Friendly