[Rd] R CMD <custom>?

Duncan Murdoch murdoch.duncan at gmail.com
Mon Nov 28 21:16:15 CET 2011

On 28/11/2011 2:48 PM, Hadley Wickham wrote:
> It'd be cool if R CMD was user extensible through packages, so that (e.g.)
> R CMD mypackage::mycommand
> would do something like:
> path<- system.file("cmd", paste(command, ".r"), package = package)
> if (!file.exists(path)) {
>    stop("Command ", command, " in ", package, " does not exist")
> } else {
>    source(path)
> }
> And maybe `R CMD mypackage` would look in mypackcage/cmd/default.r.

That does seem to mix up namespaces quite a bit.  But what does it get 
you that "Rscript -e" doesn't already give you?  You can set up your 
package so that

R CMD mypackage::mycommand

executes a function, using delayedAssign or some of the more exotic 
features (like external pointers and finalizers).

Duncan Murdoch

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