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

On Tue, Sep 26, 2017 at 11:56 AM, G?bor Cs?rdi <csardi.gabor at gmail.com> wrote:

On Tue, Sep 26, 2017 at 10:35 AM, Joris Meys <Joris.Meys at ugent.be> wrote:

I don't like the dropping of dimensions either. That doesn't change the
fact that a tibble reacts different from a data.frame. So tibbles do not
inherit correctly from the class data.frame, and it can thus be argued that
it's against OOP paradigms to pretend tibbles inherit from the class
data.frame.

I have yet to see an OOP system in which a subclass cannot override the methods
of its superclass. Not only is this in line with OOP paradigms, it is
actually one of the essential OOP features.

Not if this compromises type safety. Formal OOP languages enforce the
signature matches when you override a method. The fact that R is
dynamically typed puts this responsibility at the developer. The fact
that tibble [ returns a data frame where it's parent class returns an
atomic vector violates this principle, resulting in the obvious type
errors where tibbles are used as data frames.