[R] Strange behavior of is.na() on lists

[Duncan Murdoch]

On Sat, 25 Sep 2004 18:26:11 +0200, Adrian Alexa
<adrian.alexa at gmail.com> wrote:

>Hello R-users, 
>
>
>I have observed that is.na() behaves strange on some lists. Here is a
>simple example:
>
>
>> a = list(list('asd'))
>> a
>[[1]]
>[[1]][[1]]
>[1] "asd"
>
>
>> for(i in 1:5)
>+ print(is.na(a))
>[1] TRUE
>[1] FALSE
>[1] TRUE
>[1] TRUE
>[1] TRUE

Yes, this is a bug.  The problem is that the code leaves the result
unset in this case (no default on an incomplete switch statement).
I'll fix it.

Thanks for the report!

Duncan Murdoch