Is it necessary to export these functions? Can't they simply be inlined? If we prefer to avoid changing the NAMESPACE, etc. Otherwise, it's fine.

EDIT: Because, as you see in the mention above, others may start depending upon this driver, instead of just using the appropriate package designed and maintained for this. :)

Is it necessary to export these functions?

I have three or four (or five) other package where I am doing the pdfpages thing, and this approach is better. But to use it from another package I need to export them. I could put them elsewhere but these other packages also already use Rcpp so it makes some sense...

And yes I could use R.rsp but

> p <- tools::package_dependencies("R.rsp", recursive=TRUE, db=db)[[1]]
> p
[1] "methods"     "stats"       "tools"       "utils"       "R.methodsS3" "R.oo"        "R.utils"    
[8] "R.cache"     "digest"     
> 

it pulls half a dozen packages with it.

FWIW ... I'm in similar situation as @eddelbuettel - already using Rcpp and this seems like a very lightweight way to get the vignette.

The help entry is very helpful; you could make it less so and maybe indicate that it is intended for RcppCore use only if you really don't want the public to pick it up. I would definitely not use this if you said please don't use.

Anyway, thanks for showing us how to do this!

KTB

Hey @kylebaron thanks for chiming in! As you read along my musings, there really are three possible methods and this one (despite the added tiny export of two new functions -- but hey I found another one to retire so it's not all bad ...) is my current favourite. Because keeping rmarkdown (or otherwise) made pdfs 'as is' is good, and having a non-intrusive way to pass these one seems good too. And my previous approach (using latex pdfpages via Rnw) swallos pdf links so that is not as good as I thought it was...

Mmh, but it seems it is possible to register the vignette engine without exporting the weave and tangle function, as knitr does if I'm not missing anything.

The registration call would be (in another client package)

    tools::vignetteEngine("asis", package = pkgname, pattern = "[.](pdf|html)[.]asis$",
                          weave = Rcpp::asisWeave, tangle = Rcpp::asisTangle)	# nocov end

How can we do that without exporting the two tagged functions? There could well be a way I am not seeing right now, what we have in this PR follows the model of R.rsp and it exports the two and has them used by other packages. I was aiming for the same model. Can you do better than I have here?

But the client package just needs to set VignetteBuilder to Rcpp::asis, right?, because it's already registered by Rcpp.

I mean I certainly don't call tools::vignetteEngine in my packages to use knitr's engine, or R.rsp's for that matter. I just set the VignetteBuilder tag/variable and suggest the package with the engine.

Good point, I think I had overlooked that part. In which case asisWeave and asisTange may remain documented but not exported.

And confirmed by adopting RcppAnnoy to use this. Works without exporting, will commit small improvement to PR. Smaller exported surface is better, thanks for catching this.