Runnable R packages

In summary, I'm convinced R would benefit from something similar to Java's
`Main-Class` header or Python's `__main__()` function. A new R CMD command
would take a package, install its dependencies, and run its "main"
function.

I just created and built a very boilerplate R package called "runme". I can
install its dependencies and run its "main" function with:

 $ R CMD INSTALL runme_0.0.0.9000.tar.gz
 $ R -e 'runme::main()'

No new R CMDs needed. Now my choice of "main" is arbitrary, whereas with
python and java and C the entrypoint is more tightly specified (__name__ ==
"__main__" in python, int main(..) in C and so on). But I don't think
that's much of a problem.

Does that not satisfy your requirements close enough? If you want it in one
line then:

R CMD INSTALL runme_0.0.0.9000.tar.gz && R -e 'runme::main()'

will do the second if the first succeeds (Unix shells).

You could write a script for $RHOME/bin/RUN which would be a two-liner and
that could mandate the use of "main" as an entry point. But good luck
getting anything into base R.

Barry

If we have this machinery available, we could even consider
reaching out to Spark (and other tech stacks) developers and make it easier
to develop R applications for those platforms.