[R] Partial matching list elements in R 4.0

[William Dunlap]

Another symptom of this problem is:

> {x <- list(Abc=list(Pqr="Old Abc$Pqr")); x$Ab$Pqr <- "New Ab$Pqr" ; x}
R version 3.6.2 (2019-12-12) | R version 4.0.0 (2020-04-24)
List of 2                    | List of 2
 $ Abc:List of 1             |  $ Abc:List of 1
  ..$ Pqr: chr "Old Abc$Pqr" |   ..$ Pqr: chr "New Ab$Pqr"
 $ Ab :List of 1             |  $ Ab :List of 1
  ..$ Pqr: chr "New Ab$Pqr"  |   ..$ Pqr: chr "New Ab$Pqr"

Bill Dunlap
TIBCO Software
wdunlap tibco.com


On Tue, May 26, 2020 at 10:45 AM John Harrold <john.m.harrold using gmail.com>
wrote:

> Hello,
>
>
> I'm testing some code in R 4.0, and I'm having an issue with the following"
>
> # -------------
> rm(list=ls())
> graphics.off()
> #load("/tmp/post.RData")
> var = list();
> # If I uncomment this it fixes things:
> # var$options = list(mi   = list(),
> #                    misc = list())
> #
> var$options$misc$abc = "123"
> var$options$mi$something    = 13
> #------------
>
> This is a stripped down example but it exhibits the issue I"m having.
> Basically when I create the list element var$options$mi the contents of
> var$options$misc move over to var$options$mi. And what was in
> var$options$misc become NULL:
>
> So now var$options looks like:
>
> var$options
> $misc
> $misc$abc
> NULL
>
> $mi
> $mi$abc
> [1] "123"
> $mi$something
> [1] 13
>
> This worked (still works) in R 3.5.1. I understand partial matching, but is
> this normal lists moving over to elements like this? I can uncomment the
> text mentioned in the example and it seems to fix it, but I'm wondering if
> this is a bug or just my poor programming coming back to bite me.
>
> I've included my sessionInfo() at the bottom.
>
> Thanks
> John
> :wq
>
>
> sessionInfo()
>
> R version 4.0.0 (2020-04-24)
>
> Platform: x86_64-apple-darwin17.0 (64-bit)
>
> Running under: macOS Mojave 10.14.5
>
>
> Matrix products: default
>
> BLAS:
> /Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRblas.dylib
>
> LAPACK:
> /Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRlapack.dylib
>
>
> locale:
>
> [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
>
>
> attached base packages:
>
> [1] stats     graphics  grDevices utils     datasets  methods   base
>
>
> other attached packages:
>
> [1] gdata_2.18.0  ggplot2_3.3.0 deSolve_1.28
>
>
> loaded via a namespace (and not attached):
>
>  [1] Rcpp_1.0.4.6     gtools_3.8.2     withr_2.2.0      assertthat_0.2.1
>
>  [5] dplyr_0.8.5      digest_0.6.25    crayon_1.3.4     grid_4.0.0
>
>  [9] R6_2.4.1         lifecycle_0.2.0  gtable_0.3.0     magrittr_1.5
>
> [13] scales_1.1.1     pillar_1.4.4     rlang_0.4.6      vctrs_0.3.0
>
> [17] ellipsis_0.3.1   glue_1.4.1       purrr_0.3.4      munsell_0.5.0
>
> [21] compiler_4.0.0   pkgconfig_2.0.3  colorspace_1.4-1 tidyselect_1.1.0
>
> [25] tibble_3.0.1
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

	[[alternative HTML version deleted]]