R devel - Aug 2010 - readline operate-and-get-next

Both Bash and Octave have a nifty addition to the readline library called
"operate-and-get-next", bound to "C-o".  This function
accepts the
current line for execution and fetch the next line relative to the
current line from the history for editing (see
http://www.faqs.org/docs/bashman/bashref_101.html).

This feature has a huge impact in my productivity using Bash and Octave
interactively, since it avoids those numerous arrow key strokes in order
to rerun a previous block of commands. 

I looked at the Bash sources and it does not seem too complicate to
implement.  Octave has borrowed practically the same code from Bash.
Before I start looking at the R code, I would like to know whether the R
developers had already planned to include the operate-and-get-next
feature into R.

Best regards,

Rafael Laboissiere

Okay, I could not refrain myself and implemented the change in
src/unix/sys-std.c.  The patch is attached below.  I tested it in the
2.11.1 source and it worked fine.  At any rate, the patch applies cleanly
to the SVN source.

Three notes about this patch:

1. The code is taken from the bash source (bashline.c) with minimal
   changes.
   
2. The changes are put inside #ifdef HAVE_READLINE_HISTORY_H, because
   it uses history related functions.
   
3. In the call to rl_add_defun, the operate-and-get-next function is
   bound to C-o.  This is not the behavior of Bash and Octave, which
   depends on the user to define the key binding in ~/.inputrc.  To
   mimic this behavior, the code should be rather:

   rl_add_defun ("operate-and-get-next", operate_and_get_next, -1);


Best regards,

Rafael Laboissiere

* Rafael Laboissiere <rafael.laboissiere at inserm.fr> [2010-08-07 13:07]:
> Both Bash and Octave have a nifty addition to the readline library called
> "operate-and-get-next", bound to "C-o".  This function
accepts the
> current line for execution and fetch the next line relative to the
> current line from the history for editing (see
> http://www.faqs.org/docs/bashman/bashref_101.html).
> 
> This feature has a huge impact in my productivity using Bash and Octave
> interactively, since it avoids those numerous arrow key strokes in order
> to rerun a previous block of commands. 
> 
> I looked at the Bash sources and it does not seem too complicate to
> implement.  Octave has borrowed practically the same code from Bash.
> Before I start looking at the R code, I would like to know whether the R
> developers had already planned to include the operate-and-get-next
> feature into R.
> 
> Best regards,
> 
> Rafael Laboissiere
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Dear Prof Ripley,

* Rafael Laboissiere <rafael.laboissiere at inserm.fr> [2010-08-14 20:55]:
> * Rafael Laboissiere <rafael.laboissiere at inserm.fr> [2010-08-12
20:24]:
> 
> I did not hear from you but I went ahead and prepared a patch according
> to your recommendations, attached below.  I hope that the copyright and
> licensing issues are correctly sorted out now.
> 
> [snip]
Have you had a chance to review the operate-and-get-next patch that I
posted to r-devel last month?

Best regards,

Rafael Laboissi?re