[Rd] "$<-" fails (invalid subscript type 'language')

[David Winsemius]

On Oct 24, 2010, at 5:35 AM, Vitalie S. wrote:

>
> This might be just beyond of my understanding of how assignment  
> works in R, but
> the documentation does not say anything about:
>
>> tv <- c(a="dsf", b="sss")
>> tl <- list(232)
>> `$<-`(tl, tv[[1]], "sdfdsfdsfsd")
> Error: invalid subscript type 'language'

Are either of these what you should have done to get what it appears  
you were aiming for but didn't specify?

  `$<-`(tl, "sdfdsfdsfsd", tv[[1]])
# yields
[[1]]
[1] 232

$sdfdsfdsfsd
[1] "dsf"

 > `[<-`(tl, tv[[1]], "sdfdsfdsfsd")
[[1]]
[1] 232

$dsf
[1] "sdfdsfdsfsd"

The "$" operator does not evaluate the index whereas the "[" function  
does. And the documentation is quite clear about that distinction.

-- 
David Winsemius.


>
> This happens even before the method is dispatched. I can not handle  
> the
> "name" argument in my S4 method, because it's not even entered.
>
> Thanks,
> Vitalie.