[Rd] str() not displaying names

Martin Maechler maechler at stat.math.ethz.ch
Sat Nov 25 22:06:08 CET 2017

>>>>> Martin Maechler <maechler at stat.math.ethz.ch>
>>>>>     on Thu, 16 Nov 2017 22:00:16 +0100 writes:

    > [This is a "re-post" -- for some reason it never appeared
    > on R-devel]
>>>>> Etienne Sanchez <etiennesanchez2 at gmail.com>
>>>>> on Tue, 14 Nov 2017 19:33:07 +0100 writes:

    >> In some cases, str() does not print the "names" attribute
    >> of the object:
    >> u <- structure(c(5, 6), names = c("a", "b"), color =
    >> "blue")

    >> str(u) # atomic [1:2] 5 6 # - attr(*, "color")= chr
    >> "blue"
    >> Is it a bug or a design choice?

    >> Originally asked here:
    >> https://stackoverflow.com/q/47185756/6656269

    > It's not a bug in the sense that a long time ago -- when I
    > wrote the first version of str(), for S-plus, before R
    > existed -- I had decided that when is.vector(.) was false,
    > for whatever reason, the atomic vectors should be shown as
    > above.

    > I don't remember if S-plus used the same somewhat
    > surprising definition of is.vector(.) as R does (but I
    > think it did): it is only TRUE for a vector that has no
    > other attributes than possibly "names".

    > I did occasionally find that the historical choice
    > probably was not quite the best in hindsight, but never
    > got convinced that it should be changed...  Once I'll have
    > finished the deparse/dput/dump changes in R-devel
    > (hopefully within a week), and as R-devel has quite a few
    > small changes to R <= 3.4.x anyway, I may consider to
    > change utils:::str.default here ... and have a few dozens
    > of package maintainers and R users live with the fact the
    > str() outputs will have changed in late spring next year
    > ...

    > Notably if you or other give convincing reasons why it's
    > worth to change... but note that it's quite easy to give
    > "Pro" reasons, but there are "Cons" and for such cases a
    > lot of "Cons" are related to "there must 100's of 1000s of
    > R code lines using str(), and so there will be 100s of
    > places where the output changes, ( ... but then I'd
    > guestimate that the change would be to the better in most
    > cases).

I have been daring (again!)  and did change  str()   so it will
typically no longer print the ominous  "atomic" in such cases.

This is for "R-devel" with svn rev >= 73780 ..

It will slightly change str() output for such cases, but in the
half a dozen cases I've looked the cases were always for the


Martin Maechler
ETH Zurich and R Core

More information about the R-devel mailing list