On 03/28/2018 08:31 AM, Jialin Ma wrote:
Dear all,
It seems that as.pairlist does not convert call objects, producing
results like the following:
is.pairlist(as.pairlist(quote(x + y)))
[1] FALSE
Should this behavior be expected?
The documentation says that the behavior of as.pairlist is undocumented
in this case:
"
‘as.pairlist’ is implemented as ‘as.vector(x, "pairlist")’, and
hence will dispatch methods for the generic function ‘as.vector’.
Lists are copied element-by-element into a pairlist and the names
of the list used as tags for the pairlist: the return value for
other types of argument is undocumented.
"
as.pairlist implementation does currently nothing for a language object
(because it is internally represented using a linked list). is.pairlist
implementation is checking whether it's argument is a user-level
pairlist, which language object is not, so it returns FALSE in the example.
These functions are rather low-level and should not be needed in user
programs. Certainly programs should not depend on undocumented behavior.
Tomas
Thanks,
Jialin
sessionInfo()
R version 3.4.1 (2017-06-30)
Platform: x86_64-suse-linux-gnu (64-bit)
Running under: openSUSE Tumbleweed
Matrix products: default
BLAS: /usr/lib64/R/lib/libRblas.so
LAPACK: /usr/lib64/R/lib/libRlapack.so
locale:
[1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C
[3] LC_TIME=en_US.UTF-8 LC_COLLATE=en_US.UTF-8
[5] LC_MONETARY=en_US.UTF-8 LC_MESSAGES=en_US.UTF-8
[7] LC_PAPER=en_US.UTF-8 LC_NAME=C
[9] LC_ADDRESS=C LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
attached base packages:
[1] stats graphics grDevices utils datasets methods
[7] base
other attached packages:
[1] magrittr_1.5
______________________________________________
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
