[R-pkg-devel] Handling Not-Always-Needed Dependencies?

[Duncan Murdoch]

On 02/08/2016 1:41 PM, Dirk Eddelbuettel wrote:
>
> On 2 August 2016 at 13:12, Duncan Murdoch wrote:
> | On 02/08/2016 1:01 PM, Dirk Eddelbuettel wrote:
> | >
> | > On 2 August 2016 at 11:36, Joshua Ulrich wrote:
> | > | Maybe I'm missing something, but isn't that the point of calling
> | > | requireNamespace()?  For example:
> | > | if (requireNamespace("suggestedPackage"))
> | > |   stop("suggestedPackage required but not installed")
> | > |
> | > | That doesn't seem like a heavy burden for package writers when writing
> | > | infrequently used functions in their package.  You could even add the
> | > | install.packages command to the error message to instruct users to
> | > | install the required package.
> | >
> | > [...]
> | >
> | > | I personally would not want install.packages() to install packages I'm
> | > | unlikely to actually use.
> | > |
> | > | It's also not clear to me how importing rarely used functions causes
> | > | bloat, but installing all packages for all rarely-used functions does
> | > | not cause bloat.
> | >
> | > Sadly, some people whose advocacy is taken as religous gospel in some
> | > circles, particularly beginners, advocate pretty much that: treat Suggests:
> | > as Depends: and install it anyway because, hell, why would one tests.
> | >
> | > I regularly run (large) reverse depends checks against some of my more widely
> | > used packages and run into this all the time.
> | >
> | > We (as a community, including CRAN whose gatekeepers I have failed to
> | > convince about this on on multiple attempts) are doing this wrong.
> | > "Suggests:" really means optionally, rather than unconditionally.  But it
> | > would appear that you and I are about to only ones desiring that behaviour.
> |
> | I thought I understood Joshua's point (and agreed with it), but you also
> | seem to be agreeing with him and I don't understand at all what you're
> | saying.
> |
> | What is "this" in your last paragraph, that you have failed to convince
> | CRAN gatekeepers about?
>
> It is really simple:  Having _both_ Suggests: foo _and_ an unconditonal call
> to foo::bar() in the code.
>
> Whereas Josh and I argue that it needs to be conditional on requireNames()
> coming back TRUE.

I am feeling particularly dense today.  What about "Having _both_ 
Suggests: foo _and_ an unconditonal call to foo::bar() in the code." did 
you fail to convince CRAN about?  That it is a good thing, or a bad thing?

Duncan Murdoch