Hi Martin et al,
On Thu, May 21, 2020 at 9:42 AM Martin Maechler
<maech...@stat.math.ethz.ch <mailto:maech...@stat.math.ethz.ch>> wrote:
>>>>> Hervé Pagès
>>>>> on Fri, 15 May 2020 13:44:28 -0700 writes:
> There is still the situation where **both** 'sep' and
'collapse' are
> specified:
>> paste(integer(0), "nth", sep="", collapse=",")
> [1] "nth"
> In that case 'recycle0' should **not** be ignored i.e.
> paste(integer(0), "nth", sep="", collapse=",", recycle0=TRUE)
> should return the empty string (and not character(0) like it
does at the
> moment).
> In other words, 'recycle0' should only control the first
operation (the
> operation controlled by 'sep'). Which makes plenty of sense:
the 1st
> operation is binary (or n-ary) while the collapse operation
is unary.
> There is no concept of recycling in the context of unary
operations.
Interesting, ..., and sounding somewhat convincing.
> On 5/15/20 11:25, Gabriel Becker wrote:
>> Hi all,
>>
>> This makes sense to me, but I would think that recycle0 and
collapse
>> should actually be incompatible and paste should throw an
error if
>> recycle0 were TRUE and collapse were declared in the same
call. I don't
>> think the value of recycle0 should be silently ignored if it
is actively
>> specified.
>>
>> ~G
Just to summarize what I think we should know and agree (or be
be "disproven") and where this comes from ...
1) recycle0 is a new R 4.0.0 option in paste() / paste0() which by
default
(recycle0 = FALSE) should (and *does* AFAIK) not change anything,
hence paste() / paste0() behave completely back-compatible
if recycle0 is kept to FALSE.
2) recycle0 = TRUE is meant to give different behavior, notably
0-length arguments (among '...') should result in 0-length results.
The above does not specify what this means in detail, see 3)
3) The current R 4.0.0 implementation (for which I'm primarily
responsible)
and help(paste) are in accordance.
Notably the help page (Arguments -> 'recycle0' ; Details 1st
para ; Examples)
says and shows how the 4.0.0 implementation has been meant to work.
4) Several provenly smart members of the R community argue that
both the implementation and the documentation of 'recycle0 =
TRUE' should be changed to be more logical / coherent / sensical ..
Is the above all correct in your view?
Assuming yes, I read basically two proposals, both agreeing
that recycle0 = TRUE should only ever apply to the action of 'sep'
but not the action of 'collapse'.
1) Bill and Hervé (I think) propose that 'recycle0' should have
no effect whenever 'collapse = <string>'
2) Gabe proposes that 'collapse = <string>' and 'recycle0 = TRUE'
should be declared incompatible and error. If going in that
direction, I could also see them to give a warning (and
continue as if recycle = FALSE).
Herve makes a good point about when sep and collapse are both set. That
said, if the user explicitly sets recycle0, Personally, I don't think it
should be silently ignored under any configuration of other arguments.
If all of the arguments are to go into effect, the question then becomes
one of ordering, I think.
Consider
paste(c("a", "b"), NULL, c("c", "d"), sep = " ", collapse = ",",
recycle0=TRUE)
Currently that returns character(0), becuase the logic is
essenttially (in pseudo-code)
collapse(paste(c("a", "b"), NULL, c("c", "d"), sep = " ",
recycle0=TRUE), collapse = ", ", recycle0=TRUE)
-> collapse(character(0), collapse = ", " recycle0=TRUE)
-> character(0)
Now Bill Dunlap argued, fairly convincingly I think, that paste(...,
collapse=<string>) should /always/ return a character vector of length
exactly one. With recycle0, though, it will return "" via the progression
paste(c("a", "b"), NULL, c("c", "d"), sep = " ", collapse = ",",
recycle0=TRUE)
-> collapse(character(0), collapse = ", ")
-> ""
because recycle0 is still applied to the sep-based operation which
occurs before collapse, thus leaving a vector of length 0 to collapse.
That is consistent but seems unlikely to be what the user wanted, imho.
I think if it does this there should be at least a warning when paste
collapses to "" this way, if it is allowed at all (ie if mixing
collapse=<string>and recycle0=TRUEis not simply made an error).
I would like to hear others' thoughts as well though. @Pages, Herve
<mailto:hpa...@fredhutch.org> @William Dunlap
<mailto:wdun...@tibco.com> is "" what you envision as thee desired and
useful behavior there?
Best,
~G
I have not yet my mind up but would tend to agree to "you guys",
but I think that other R Core members should chime in, too.
Martin
>> On Fri, May 15, 2020 at 11:05 AM Hervé Pagès
<hpa...@fredhutch.org <mailto:hpa...@fredhutch.org>
>> <mailto:hpa...@fredhutch.org <mailto:hpa...@fredhutch.org>>>
wrote:
>>
>> Totally agree with that.
>>
>> H.
>>
>> On 5/15/20 10:34, William Dunlap via R-devel wrote:
>> > I agree: paste(collapse="something", ...) should always
return a
>> single
>> > character string, regardless of the value of recycle0.
This would be
>> > similar to when there are no non-NULL arguments to paste;
>> collapse="."
>> > gives a single empty string and collapse=NULL gives a zero
long
>> character
>> > vector.
>> >> paste()
>> > character(0)
>> >> paste(collapse=", ")
>> > [1] ""
>> >
>> > Bill Dunlap
>> > TIBCO Software
>> > wdunlap tibco.com
<https://urldefense.proofpoint.com/v2/url?u=http-3A__tibco.com&d=DwMFaQ&c=eRAMFD45gAfqt84VtBcfhQ&r=BK7q3XeAvimeWdGbWY_wJYbW0WYiZvSXAJJKaaPhzWA&m=q5ueyHReS5hHK6TZ0dJ1N7Ro8dx-rsLHys8GrCugOls&s=o9ozvxBK-kVvAUFro7U1RrI5w0U8EPb0uyjQwMvOpt8&e=>
>>
<https://urldefense.proofpoint.com/v2/url?u=http-3A__tibco.com&d=DwMFaQ&c=eRAMFD45gAfqt84VtBcfhQ&r=BK7q3XeAvimeWdGbWY_wJYbW0WYiZvSXAJJKaaPhzWA&m=cC2qctlVXd0qHMPvCyYvuVMqR8GU3DjTTqKJ0zjIFj8&s=rXIwWqf4U4HZS_bjUT3KfA9ARaV5YTb_kEcXWHnkt-c&e=>
>> >
>> >
>> > On Thu, Apr 30, 2020 at 9:56 PM suharto_anggono--- via
R-devel <
>> > r-devel@r-project.org <mailto:r-devel@r-project.org>
<mailto:r-devel@r-project.org <mailto:r-devel@r-project.org>>> wrote:
>> >
>> >> Without 'collapse', 'paste' pastes (concatenates) its
arguments
>> >> elementwise (separated by 'sep', " " by default). New in
R devel
>> and R
>> >> patched, specifying recycle0 = FALSE makes mixing
zero-length and
>> >> nonzero-length arguments results in length zero. The
result of
>> paste(n,
>> >> "th", sep = "", recycle0 = FALSE) always have the same
length as
>> 'n'.
>> >> Previously, the result is still as long as the longest
argument,
>> with the
>> >> zero-length argument like "". If all og the arguments have
>> length zero,
>> >> 'recycle0' doesn't matter.
>> >>
>> >> As far as I understand, 'paste' with 'collapse' as a
character
>> string is
>> >> supposed to put together elements of a vector into a single
>> character
>> >> string. I think 'recycle0' shouldn't change it.
>> >>
>> >> In current R devel and R patched, paste(character(0),
collapse = "",
>> >> recycle0 = FALSE) is character(0). I think it should be
"", like
>> >> paste(character(0), collapse="").
>> >>
>> >> paste(c("4", "5"), "th", sep = "", collapse = ", ",
recycle0 =
>> FALSE)
>> >> is
>> >> "4th, 5th".
>> >> paste(c("4" ), "th", sep = "", collapse = ", ",
recycle0 =
>> FALSE)
>> >> is
>> >> "4th".
>> >> I think
>> >> paste(c( ), "th", sep = "", collapse = ", ",
recycle0 =
>> FALSE)
>> >> should be
>> >> "",
>> >> not character(0).
>> >>
>> >> ______________________________________________
>> >> R-devel@r-project.org <mailto:R-devel@r-project.org>
<mailto:R-devel@r-project.org <mailto:R-devel@r-project.org>>
mailing list
>> >>
>>
https://urldefense.proofpoint.com/v2/url?u=https-3A__stat.ethz.ch_mailman_listinfo_r-2Ddevel&d=DwICAg&c=eRAMFD45gAfqt84VtBcfhQ&r=BK7q3XeAvimeWdGbWY_wJYbW0WYiZvSXAJJKaaPhzWA&m=776IovW06eUHr1EDrabHLY7F47rU9CCUEItSDI96zc0&s=xN84DhkZeoxzn6SG0QTMpOGg2w_ThmjZmZymGUuD0Uw&e=
>> >>
>> >
>> > [[alternative HTML version deleted]]
>> >
>> > ______________________________________________
>> > R-devel@r-project.org <mailto:R-devel@r-project.org>
<mailto:R-devel@r-project.org <mailto:R-devel@r-project.org>>
mailing list
>> >
>>
https://urldefense.proofpoint.com/v2/url?u=https-3A__stat.ethz.ch_mailman_listinfo_r-2Ddevel&d=DwICAg&c=eRAMFD45gAfqt84VtBcfhQ&r=BK7q3XeAvimeWdGbWY_wJYbW0WYiZvSXAJJKaaPhzWA&m=776IovW06eUHr1EDrabHLY7F47rU9CCUEItSDI96zc0&s=xN84DhkZeoxzn6SG0QTMpOGg2w_ThmjZmZymGUuD0Uw&e=
>> >
>>
>> --
>> 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 <mailto:hpa...@fredhutch.org>
<mailto:hpa...@fredhutch.org <mailto:hpa...@fredhutch.org>>
>> Phone: (206) 667-5791
>> Fax: (206) 667-1319
>>
>> ______________________________________________
>> R-devel@r-project.org <mailto:R-devel@r-project.org>
<mailto:R-devel@r-project.org <mailto:R-devel@r-project.org>>
mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-devel
<https://urldefense.proofpoint.com/v2/url?u=https-3A__stat.ethz.ch_mailman_listinfo_r-2Ddevel&d=DwMFaQ&c=eRAMFD45gAfqt84VtBcfhQ&r=BK7q3XeAvimeWdGbWY_wJYbW0WYiZvSXAJJKaaPhzWA&m=q5ueyHReS5hHK6TZ0dJ1N7Ro8dx-rsLHys8GrCugOls&s=OLA7CqaU5uKeid1aGw41XJ_2Uq7JXbcwpPOrTWWG2v4&e=>
>>
<https://urldefense.proofpoint.com/v2/url?u=https-3A__stat.ethz.ch_mailman_listinfo_r-2Ddevel&d=DwMFaQ&c=eRAMFD45gAfqt84VtBcfhQ&r=BK7q3XeAvimeWdGbWY_wJYbW0WYiZvSXAJJKaaPhzWA&m=cC2qctlVXd0qHMPvCyYvuVMqR8GU3DjTTqKJ0zjIFj8&s=COnDeGgHNnHJlLLZOznMlhcaFU1nIRlkaSbssvlrMvw&e=>
>>
> --
> 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 <mailto:hpa...@fredhutch.org>
> Phone: (206) 667-5791
> Fax: (206) 667-1319
> ______________________________________________
> R-devel@r-project.org <mailto:R-devel@r-project.org> mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
<https://urldefense.proofpoint.com/v2/url?u=https-3A__stat.ethz.ch_mailman_listinfo_r-2Ddevel&d=DwMFaQ&c=eRAMFD45gAfqt84VtBcfhQ&r=BK7q3XeAvimeWdGbWY_wJYbW0WYiZvSXAJJKaaPhzWA&m=q5ueyHReS5hHK6TZ0dJ1N7Ro8dx-rsLHys8GrCugOls&s=OLA7CqaU5uKeid1aGw41XJ_2Uq7JXbcwpPOrTWWG2v4&e=>
