[R-pkg-devel] dependency cycle

[Dirk Eddelbuettel]

On 13 June 2017 at 13:01, Berry Boessenkool wrote:
| 
| Hi,
| 
| I have a package A. Some of its functions are used in package B.
| 
| B imports A in the DESCRIPTION, both are on CRAN.
| 
| A has a function fff where I want to add some optional functionality.
| 
| The problem: that optional stuff uses code in package B.
| 
| 
| I feel like I have two bad options:
| 
| - put fff in a package C that imports both A and B.
| However, C would really be too small to be on CRAN.
| Also, some people already know of A::fff and I'm rather inclined to keep it there.
| 
| - put B in Suggests and make the optional part of fff conditional on requireNamespace("B").
| 
| But then B imports A while A suggests B, which sounds dangerous.
| 
| 
| Any ideas on what I could/should do here?

My Google-Fu is weak this morning but I think we just that discussion here.

Usual tip: Disentangle.  Create package C with common code.  Have A use
it. Have B use A.  No cycles.

Dirk

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