[R-pkg-devel] tibbles are not data frames

[Göran Broström]

I am beginning to get complaints from users of my CRAN packages 
(especially 'eha') to the effect that they get error messages like 
"Error: Unsupported use of matrix or array for column indexing".

It turns out that they are sticking in tibbles into functions that 
expect data frames as input. And I am using the kind of subsetting that 
Hadley dislikes (eha is an old package, much older than tibbles). It is 
of course a simple matter to change the code so it handles both data 
frames and tibbles correctly, but this affects many functions, and it 
will take some time. And when the next guy introduces 'troubles' as an 
improvement of 'tibbles', I will have to rewrite the code again.

While I like Hadley's way of doing it, I think it is a mistake to let a 
tibble also be of class data frame. To me it is a matter of inheritance 
and backwards compability: A tibble should add nice things to a data 
frame, not change basic behaviour, in order to call itself a data frame.

Is it correct to let a tibble be of class "data.frame"?

Göran Broström