[Rd] List's `[[` method with "" tag
Hi, I notice that one can assign a variable to an R list by using an empty string key but one cannot get that variable back from the list by using the empty string key: ```r l <- list() l[[""]] <- "An empty string as list key" names(l) l[[""]] # Returns a `NULL` l[[names(l) == ""]] # Returns first value with `""` tag ``` Instead of `l[[""]]` returning a `NULL` I'd "expect" it to instead return the first variable named `""` i.e. in this case "An empty string as list key". It would be nice if the `[[` method of a list was updated to "fix" this. Additionally, I observe that if a list is named but has certain elements without names then those are currently "named" `""`: ```r names(list(a = 1, 2, c = 3, 4)) ``` This latter change may be a breaking change but I speculate that perhaps it may be more intuitive if missing names were indicated with `NA_character_` instead of `""`. Thanks, Trevor [[alternative HTML version deleted]] __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
Re: [Rd] List's `[[` method with "" tag
It's per design: ?names ... The name '""' is special: it is used to indicate that there is no name associated with an element of a (atomic or generic) vector. Subscripting by '""' will match nothing (not even elements which have no name). ... Best, Serguei. Le 2023-09-11 18:29, Trevor Davis a écrit : > Hi, > > I notice that one can assign a variable to an R list by using an empty > string key but one cannot get that variable back from the list by using the > empty string key: > > ```r > l <- list() > l[[""]] <- "An empty string as list key" > names(l) > l[[""]] # Returns a `NULL` > l[[names(l) == ""]] # Returns first value with `""` tag > ``` > > Instead of `l[[""]]` returning a `NULL` I'd "expect" it to instead return > the first variable named `""` i.e. in this case "An empty string as list > key". It would be nice if the `[[` method of a list was updated to "fix" > this. > > Additionally, I observe that if a list is named but has certain elements > without names then those are currently "named" `""`: > > ```r > names(list(a = 1, 2, c = 3, 4)) > ``` > > This latter change may be a breaking change but I speculate that perhaps it > may be more intuitive if missing names were indicated with `NA_character_` > instead of `""`. > > Thanks, > > Trevor > > [[alternative HTML version deleted]] > > __ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel [[alternative HTML version deleted]] __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
Re: [Rd] FYI: daily R source tarballs from ETH: *.xz instead of *.bz2)
On 09/09/2023 01:56, Hervé Pagès wrote: Hi Martin, Sounds good. Are there any plans to support the xz compression for package source tarballs? What makes you think it is not supported? R CMD INSTALL happily installs .tar.xz files, and the name is not used to detect compression so .tar.gz files could be bzip2- or xz-compressed. Note that tarball compression is pretty much irrelevant where the tarball contains large compressed files, for example .rda files or vendor.tar.xz files of Rust sources. You have to arrange that the first compression is the bast possible. -- Brian D. Ripley, rip...@stats.ox.ac.uk Emeritus Professor of Applied Statistics, University of Oxford __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
