[Rd] ANN/RFC: package providing TAB completion for readline-based R

[Deepayan Sarkar]

Announcement:

(For those every-once-in-a-while occasions when you run R from a
terminal instead of Emacs, and then wish something would happen when
you hit TAB...)

Last week, I started looking at the GNU Readline documentation to see
if I could figure out how to use it for command completion within R.
It turned out to be easier than I had expected, and I now have a beta
version of the 'rcompletion' package available at

http://www.stat.wisc.edu/~deepayan/R/rcompletion_0.0-6.tar.gz

>From the help page:

Description:

     This package provides pseudo-intelligent TAB completion for a
     readline enabled instance of R when it is run from a terminal (or
     more specifically, an interface which uses readline to accept user
     input). It has no effect on the various GUI interfaces to R,
     including ESS and the standard Windows interface.

For more details, install and load the package, then type

package?rcompletion

at the R prompt. Testing and feedback would be appreciated. Feature
requests and patches are also welcome, of course.


Questions:

There are a couple of things about which I would like some advice:

(1) The package currently contains a very rudimentary configure script
which stops installation when readline is not found. I'm not sure if
this is portable enough. .../src/unix/sys-std.c has more sophisticated
conditional directives, but I don't know enough about this sort of
thing to interpret those. Any thoughts or suggestions on this would be
appreciated.

(2) What's the recommended procedure to distribute this, given that
(a) it's not relevant on Windows (i.e. won't do anything even if it
could be installed) and (b) may or may not be relevant on Macs, some
of which apparently have a fake readline that doesn't support
completion?

-Deepayan