[Gretl-devel] towards packages with R in the background

Hi, at the conference we agreed that in the future contributed function packages could use 'foreign' blocks that use R. (Just to be clear: the big difference here is "contributed". A function package per se can already use whatever is possible in hansl, for private use. But currently it won't be accepted to the package server if it relies on a foreign language.) We also discussed that the package author must specify the version requirement for R itself and then specify the needed R packages (along with their own versions). I would like to propose a way to put this information in the package's spec file, something like this: First a list of needed ingredients: R-packages = R glmnet The idea is that first 'R' itself needs to be explicitly mentioned, because it could be that no further R packages are needed. Also, it's just one character :-) Then the list of needed version requirements: R-versions = 3.4.3 1.9-9 Obviously, the ordering here must match that in the 'R-packages' line. As a refinement, several known-good versions might be specified in a grouped item enclosed in curly braces: R-versions = {3.4.3 3.4.4} 1.9-9 From what I understood of our discussion, gretl would not really check the version requirements, but would use this information to print a warning message at the 'include' stage. Something like: "This user-contributed gretl package requires a local R installation at the path configured in gretl's preferences. (Needed version: 3.4.3, 3.4.4) Required R packages: glmnet (version: 1.9-9) The package will likely fail (with obscure error messages) if any of those requirements are missing!" Again, since gretl won't do any real checking, the needed changes do not seem difficult, mainly a matter of documentation I guess. Comments welcome. thanks, sven