From edd at debian.org  Fri Sep 13 18:00:04 2013
From: edd at debian.org (Dirk Eddelbuettel)
Date: Fri, 13 Sep 2013 11:00:04 -0500
Subject: [Rd] declaring package dependencies
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On 13 September 2013 at 11:42, Paul Gilbert wrote:
| On 13-09-13 11:02 AM, Dirk Eddelbuettel wrote:
| > It's not so much Rcpp itself or my 20-ish packages but the fact that we (as
| > in the Rcpp authors) now stand behind an API that also has to accomodate
| > changes in R CMD check. Case in point is current (unannounced) change that
| > makes all Depends: Rcpp become Imports: Rcpp because of the NAMESPACE checks.
| 
| I am a bit confused by this Dirk, so maybe I am missing something. I 
| think this is still a "Note" in R-devel so you do have some time to make 
| the change, at least several months, maybe more. It is not quite what I 
| think of as an "announcement", more like a shot across the bow, but it 
| is also not "unannounced".

One package author [as in user of Rcpp and not an author of it] was told by
CRAN this week to change his package and came to me for help -- so in that
small way the CRAN "non-communication policy" is already creating more work
for me, and makes me look silly as "I don't document what Rcpp-using packages
need" as I sadly still lack the time machine or psychic powers to infer what
may get changed this weekend.
 
| More importantly, I don't think that the requirement is necessarily to 
| change Depends: Rcpp to Imports: Rcpp, the requirement is to put 
| imports(Rcpp) in the NAMESPACE file. I think this is so that the package 
| continues to work even if the user does something with the search path. 
| The decision to change Depends: Rcpp to Imports: Rcpp really depends on 
| whether the package author wants Rcpp functions to be available directly 

Rcpp is a bit of an odd-ball as you mostly need it at compile-time, and you
require very few R-level functions (but there is package initialization etc
pp).  We also only about two handful of functions, and those are for
functionality not all 135 packages use (eg Modules etc).   

But the focus here should not be on my hobby package. The focus needs to be
on how four CRAN maintainers (who do a boatload of amazing work which is
_truly_ appreciated in its thoroughness and reach) could make the life of
authors of 4800+ packages easier by communicating and planning a tad more.

| by users without them needing to specifically attach Rcpp. They are 
| available with Depends but with Imports they are just used internally in 
| the package.
| 
| So, one of us is confused. Usually it is me.

No, no, I usually keep you company. 

Dirk

-- 
Dirk Eddelbuettel | edd at debian.org | http://dirk.eddelbuettel.com



[Rd] declaring package dependencies
Dirk Eddelbuettel