[ESS] Hanging emacs with ESS and R (and regretting it)

[Rodney Sparapani]

Vitalie Spinu wrote:
> Hi Rodney,
>
> I have tried all the pieces and indeed they hang emacs if
> ess-eval-visibly-p is t, irrespective of having ess-tracebug on or
> off.
>
> When I evaluate the code invisibly (C-u C-c C-b for example)
> everything is fine.
>
> There is a good reason for this, ess-eval-linewise (which does the
> visible evaluation) waits for each line to finish execution before
> sending the next one.
>
> By the way, with ess-tracebug you might consider using M-c s (aka
> _s_ource) instead of C-c C-b. It sources the file and outputs all the
> errors into the inferior buffer. In that case you can use M-[ and M-]
> to quickly navigate to the error location in the buffer. See
> navigation (http://code.google.com/p/ess-tracebug/#Navigation) and
> work-flow (http://code.google.com/p/ess-tracebug/#Work-Flow) sections
> for details.
>
> HTH,
> Vitalie.
>   
Hi Vitalie:

Excellent analysis (I wasn't blaming ess-tracebug, but merely
acknowledging it's presence ;o)  But, this is troubling to me (I'd
say this is an ESS bug rather than a feature).

The default for ess-eval-visibly-p is t (contrary to the ESS manual
which says "the behavior is controlled by the variable |ess-eval-visibly-p|
whose default is |nil|").  So, by default, a naive user (who will most
likely not have changed the default) will hang their emacs session
and think this is normal and/or acceptable behavior.  It seems to
me that the docs should, at least, mention the brackets tip/trick
(and be corrected, of course).  If no one objects, I will do that
(eventually).

-- 
Rodney Sparapani, PhD  Center for Patient Care and Outcomes Research
Sr. Biostatistician               http://www.mcw.edu/pcor
4 wheels good, 2 wheels better!   Medical College of Wisconsin (MCW)
WWLD?:  What Would Lombardi Do?   Milwaukee, WI, USA