From b@row||ng@on @end|ng |rom |@nc@@ter@@c@uk  Thu Jan 31 16:38:34 2019
From: b@row||ng@on @end|ng |rom |@nc@@ter@@c@uk (Barry Rowlingson)
Date: Thu, 31 Jan 2019 15:38:34 +0000
Subject: [Rd] Runnable R packages
In-Reply-To: <72b511b92df64f69ab43f2ce5c654584@LNXP265MB1705.GBRP265.PROD.OUTLOOK.COM>
References: <CAKtMxAFYFafUHOitKEUbRSPxXVgHd+sWe_937YHNHJOyNEm_3g@mail.gmail.com>
 <CAKtMxAHmoT=L211CJbyB034bY0ddyY8jg_QqB+LgWZCm_XgL3Q@mail.gmail.com>
 <CAPvvxJX_EFOE26vU4zBH_T2LuP7tRgV_CJx4LsvP6eN8PLZNLQ@mail.gmail.com>
 <CALEXWq2mJ=r7t4Z2akQGe1vDhu9RdHikYCGqdZy_xS1nx=YMnw@mail.gmail.com>
 <72b511b92df64f69ab43f2ce5c654584@LNXP265MB1705.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <CANVKczOZcSz0YLuKiWfdU0x3qMP0GvUAdqDgp32rmrPfHmK1tA@mail.gmail.com>

On Thu, Jan 31, 2019 at 3:14 PM David Lindelof <lindelof at ieee.org> wrote:

>
> 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.
>
>

	[[alternative HTML version deleted]]



[Rd] Runnable R packages
Barry Rowlingson