Thanks Duncan. This was very helpful. -- Bert
On Tue, Sep 11, 2012 at 4:05 AM, Duncan Murdoch <murdoch.dun...@gmail.com> wrote: > On 12-09-10 12:11 PM, Bert Gunter wrote: >> >> Hi Folks: >> >> I'm writing a little package that may not ever hit CRAN or even be >> distributed beyond a relatively narrow audience at my company. >> Nevertheless, I have tried to adhere to practices that would work if >> it were. With that in mind, I have read the Writing R Extensions >> Manual (and my humble kudos to its writers, as it has successfully >> guided even an ignoramus like myself ) and Luke Tierney's R Newsletter >> documentation on Namespaces. However, it is still not clear to me (see >> above ignoramus comment!) what functions -- and especially which S3 >> methods whose generics I define in my package -- should be exported >> and which should not. Perusing other packages also didn't reveal any >> clear patterns from which I could infer best practice. >> >> So may I ask for advice or any references that would provide such >> guidelines. Feel free to keep replies private if this query in not >> appropriate for this list. Many thanks. > > > If you export it, then you need to document it, and it needs to be usable by > others. > > Often you'll have specialized functions in a package that do what you need, > but they are too specialized to be useful to others: don't export those. > > Once you export a function, people (or maybe just yourself in some other > package or script) will start using it, so you tend to get locked in to the > interface. So don't export functions unless you want to support them in > their current form for the life of the package. > > If you export a function with the same name as one exported from another > package, it becomes inconvenient to use either function once both packages > are attached. (Which one you get depends on the order of attaching the > packages.) So don't export trivial functions, and think carefully about the > names you use for the ones you do export. > > It is slightly less convenient to test or inspect functions if you don't > export them (you need the package:::foo style to refer to them from the > console). So during early development, you may want to export more, and > limit the exports when you are happy with the package. > > Duncan Murdoch -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
