From lgautier at gmail.com  Sun Mar  8 20:22:19 2009
From: lgautier at gmail.com (Laurent Gautier)
Date: Sun, 08 Mar 2009 20:22:19 +0100
Subject: [Rd] Follow-up on the wish for a visibility flag with tryEval ?
In-Reply-To: <49B2F49A.90904@stats.uwo.ca>
References: <49B289EC.7040608@gmail.com> <49B2F49A.90904@stats.uwo.ca>
Message-ID: <49B41AEB.6090903@gmail.com>

I guess that I should have been reminding that the thread referred to is 
mostly about C API-level utilities (and the subject for this thread 
should be mentioning more precisely *R_tryEval()* ).

Wrapping evaluation from C-level in an R-level withVisible() call is 
certainly possible if this is the only way to do it:

- a C-level utility function is probably becoming handy (and that's 
mostly what the wish is about, AFAIUI).

- the traceback has at least one added layer from the call to 
withVisible(); this is something supplementary to take care of when 
writing a GUI for example.

Those are possible reasons why the threads tells that withVisible() 
[R-level] is a temporary option, waiting for something like 
R_tryEvalWithVis() [C-level].


Can't I find any such C-level because there isn't any, or because I just 
missed it ?



Thanks,





L.




Duncan Murdoch wrote:
> On 07/03/2009 9:51 AM, Laurent Gautier wrote:
>> Dear list,
>>
>> Did the wish for an official API for evaluating expressions while 
>> keeping an eye on the R_Visible flag (see:
>> https://stat.ethz.ch/pipermail/r-devel/2007-April/045258.html
>> ) lead to something ?
>>
>> I could not find a sign of it the current (R-2.8.1 and R-2.9-dev) R 
>> defines.
> 
> You should read the NEWS file, where you'll find withVisible mentioned.
> 
> Duncan Murdoch



[Rd] Follow-up on the wish for a visibility flag with tryEval ?
Laurent Gautier