This is getting pretty convoluted.
The current behavior is consistent with the description at the top of
the help page -- it does not promise to stop evaluation once the first
non-TRUE is found. That seems OK to me -- if you want sequencing you
can use
stopifnot(A)
stopifnot(B)
or
stopifnot(A && B)
I could see an argument for a change that in the multiple argumetn
case reports _all_ that fail; that would seem more useful to me than
twisting the code into knots.
Best,
luke
On Mon, 15 May 2017, Martin Maechler wrote:
Serguei Sokol <so...@insa-toulouse.fr>
on Mon, 15 May 2017 16:32:20 +0200 writes:
> Le 15/05/2017 à 15:37, Martin Maechler a écrit :
>>>>>>> Serguei Sokol <so...@insa-toulouse.fr>
>>>>>>> on Mon, 15 May 2017 13:14:34 +0200 writes:
>> > I see in the archives that the attachment cannot pass.
>> > So, here is the code:
>>
>> [....... MM: I needed to reformat etc to match closely to
>> the current source code which is in
>> https://svn.r-project.org/R/trunk/src/library/base/R/stop.R
>> or its corresponding github mirror
>> https://github.com/wch/r-source/blob/trunk/src/library/base/R/stop.R
>> ]
>>
>> > Best,
>> > Serguei.
>>
>> Yes, something like that seems even simpler than Peter's
>> suggestion...
>>
>> It currently breaks 'make check' in the R sources,
>> specifically in tests/reg-tests-2.R (lines 6574 ff),
>> the new code now gives
>>
>> > ## error messages from (C-level) evalList
>> > tst <- function(y) { stopifnot(is.numeric(y)); y+ 1 }
>> > try(tst())
>> Error in eval(cl.i, pfr) : argument "y" is missing, with no default
>>
>> whereas previously it gave
>>
>> Error in stopifnot(is.numeric(y)) :
>> argument "y" is missing, with no default
>>
>>
>> But I think that change (of call stack in such an error case) is
>> unavoidable and not a big problem.
> It can be avoided but at price of customizing error() and warning() calls
with something like:
> wrn <- function(w) {w$call <- cl.i; warning(w)}
> err <- function(e) {e$call <- cl.i; stop(e)}
> ...
> tryCatch(r <- eval(cl.i, pfr), warning=wrn, error=err)
> Serguei.
Well, a good idea, but the 'warning' case is more complicated
(and the above incorrect): I do want the warning there, but
_not_ return the warning, but rather, the result of eval() :
So this needs even more sophistication, using withCallingHandlers(.)
and maybe that really get's too sophisticated and no
more "readable" to 99.9% of the R users ... ?
I now do append my current version -- in case some may want to
comment or improve further.
Martin
--
Luke Tierney
Ralph E. Wareham Professor of Mathematical Sciences
University of Iowa Phone: 319-335-3386
Department of Statistics and Fax: 319-335-3017
Actuarial Science
241 Schaeffer Hall email: luke-tier...@uiowa.edu
Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel