[R] developing package: dealing with namespaces

[Duncan Murdoch]

On 04/02/2013 12:59 PM, Ross Boylan wrote:
> I am tweaking an R package for which I have the source; the relevant code
> is in R not C.   I'm making changes to the package code.
>
> What is the best workflow for doing this?  I recall the advice used to be
> to remove the NAMESPACE during development, but I don't think this is
> possible anymore.
>
> For simplicity, suppose I have an outer level function f defined in f.R
> and an innder g in g.R defined in the package.
>
> My understanding is that if I modify g.R and load it (e.g., C-c C-l in
> ESS) this will have no effect on the code the f calls, since the latter is
> in a namespace.
>
> If I modify f.R and import it, I'm not sure if it can find g at all if it
> has not been exported.
>
> Web searches and reviewing the R Extensions manual have turned up
> information on how to trace into functions in namesapces, but not on the
> larger development cycle.

I think the best workflow is to do the edits outside of R, and 
re-install the package to test.

It is possible to do edits to a loaded package, using the 
assignInNamespace() function, but I don't think there's a simple 
workflow that doesn't end up with multiple copies of functions, and 
possible confusion over which version
   - is in the source, so will be saved
   - is in the global env, so will be executed by a user at the top level
   - is in the namespace, so will be executed by calls from other 
functions in the namespace.

This is something that could probably be handled well by a smart 
editor.  I don't know if any of the existing IDEs do it.

Duncan Murdoch