r-devel@r-project.org
Hi everyone The following behavior (in R 3.6.1 and R-devel r77040) caught me by surprise today: truthy <- c(TRUE, FALSE) falsy <- c(FALSE, TRUE, FALSE) if (truthy) "check" #> Warning in if (truthy) "check": the condition has length > 1 and only the #> first element will be used #> [1] "check" if (falsy) "check" #> Warning in if (falsy) "check": the condition has length > 1 and only the #> first element will be used if (FALSE || truthy) "check" #> [1] "check" if (FALSE || falsy) "check" if (truthy || FALSE) "check" #> [1] "check" if (falsy || FALSE) "check" The || operator gobbles the warning about a length > 1 vector. I wonder if the existing checks for length 1 can be extended to the operands of the || and && operators. Thanks (and apologies if this has been raised before). Best regards Kirill __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
r-devel@r-project.org
NEWS for R 3.6.0:
* Experimentally, setting environment variable
_R_CHECK_LENGTH_1_LOGIC2_ will lead to warnings (or errors if the
variable is set to a ‘true’ value) when && or || encounter and use
arguments of length more than one.
> Sys.setenv("_R_CHECK_LENGTH_1_LOGIC2_" = "TRUE")
> if (FALSE || truthy) "check"
Error in FALSE || truthy :
'length(x) = 2 > 1' in coercion to 'logical(1)'
Some more info and breadcrumbs at
https://github.com/HenrikBengtsson/Wishlist-for-R/issues/48
/Henrik
On Mon, Aug 19, 2019 at 4:19 PM Kirill Müller wrote:
>
> Hi everyone
>
>
> The following behavior (in R 3.6.1 and R-devel r77040) caught me by
> surprise today:
>
> truthy <- c(TRUE, FALSE)
> falsy <- c(FALSE, TRUE, FALSE)
>
> if (truthy) "check"
> #> Warning in if (truthy) "check": the condition has length > 1 and only the
> #> first element will be used
> #> [1] "check"
> if (falsy) "check"
> #> Warning in if (falsy) "check": the condition has length > 1 and only the
> #> first element will be used
> if (FALSE || truthy) "check"
> #> [1] "check"
> if (FALSE || falsy) "check"
> if (truthy || FALSE) "check"
> #> [1] "check"
> if (falsy || FALSE) "check"
>
> The || operator gobbles the warning about a length > 1 vector. I wonder
> if the existing checks for length 1 can be extended to the operands of
> the || and && operators. Thanks (and apologies if this has been raised
> before).
>
>
> Best regards
>
> Kirill
>
> __
> R-devel@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
__
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
r-devel@r-project.org
On 19/08/2019 10:19 a.m., Kirill Müller wrote: Hi everyone The following behavior (in R 3.6.1 and R-devel r77040) caught me by surprise today: truthy <- c(TRUE, FALSE) falsy <- c(FALSE, TRUE, FALSE) if (truthy) "check" #> Warning in if (truthy) "check": the condition has length > 1 and only the #> first element will be used #> [1] "check" if (falsy) "check" #> Warning in if (falsy) "check": the condition has length > 1 and only the #> first element will be used if (FALSE || truthy) "check" #> [1] "check" if (FALSE || falsy) "check" if (truthy || FALSE) "check" #> [1] "check" if (falsy || FALSE) "check" The || operator gobbles the warning about a length > 1 vector. I wonder if the existing checks for length 1 can be extended to the operands of the || and && operators. Thanks (and apologies if this has been raised before). This seems to be an August topic. It was discussed last year in a long thread starting with this message: https://stat.ethz.ch/pipermail/r-devel/2018-August/076678.html I think there was general agreement that it would be a good idea to add some warnings. News for R 3.6.0 includes this: "Experimentally, setting environment variable _R_CHECK_LENGTH_1_LOGIC2_ will lead to warnings (or errors if the variable is set to a ‘true’ value) when && or || encounter and use arguments of length more than one." You get a warning if you set that variable to "warn", you get an error if you set it to "true". Duncan Murdoch Duncan Murdoch __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
[Rd] class() bug when used within a validity method
Hi,
This is a long-standing bug where 'class(object)' does not
return the actual class of 'object' when used inside a validity
method. Instead it seems to return the class for which the validity
method is defined. For example:
setClass("A", slots=c(stuff="ANY"))
setValidity("A", function(object) {
cat("validating an object of class:", class(object), "\n")
TRUE
})
Then:
a <- new("A")
validObject(a)
# validating an object of class: A
# [1] TRUE
which is OK. But trying to validate an object that belongs to a
subclass of A leads to a big surprise:
setClass("B", contains="A")
b <- new("B")
class(b)
# [1] "B"
validObject(b)
# validating an object of class: A
# [1] TRUE
The class of object 'b' as seen by class() is wrong.
Note that this doesn't happen if A is defined as a VIRTUAL class.
Cheers,
H.
--
Hervé Pagès
Program in Computational Biology
Division of Public Health Sciences
Fred Hutchinson Cancer Research Center
1100 Fairview Ave. N, M1-B514
P.O. Box 19024
Seattle, WA 98109-1024
E-mail: hpa...@fredhutch.org
Phone: (206) 667-5791
Fax:(206) 667-1319
__
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Re: [Rd] class() bug when used within a validity method
On 8/19/19 16:23, Pages, Herve wrote:
...
> Note that this doesn't happen if A is defined as a VIRTUAL class.
To be precise, when A is a VIRTUAL class, it requires at least
one additional level of class extension to break class():
setClass("A", contains="VIRTUAL", slots=c(stuff="ANY"))
setValidity("A", function(object) {
cat("validating an object of class:", class(object), "\n")
TRUE
})
setClass("B", contains="A")
setClass("C", contains="B")
Then:
c <- new("C")
validObject(c)
# validating an object of class: B
# [1] TRUE
H.
--
Hervé Pagès
Program in Computational Biology
Division of Public Health Sciences
Fred Hutchinson Cancer Research Center
1100 Fairview Ave. N, M1-B514
P.O. Box 19024
Seattle, WA 98109-1024
E-mail: hpa...@fredhutch.org
Phone: (206) 667-5791
Fax:(206) 667-1319
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