On Tue, Sep 26, 2017 at 8:28 AM, Jeroen Ooms <jeroeno...@gmail.com> wrote: > On Tue, Sep 26, 2017 at 11:56 AM, Gábor Csárdi <csardi.ga...@gmail.com> wrote: >> >> On Tue, Sep 26, 2017 at 10:35 AM, Joris Meys <joris.m...@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.
Where its parent class _sometimes_ returns an atomic vector and _sometimes_ returns a data frame. Hadley -- http://hadley.nz ______________________________________________ R-package-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-package-devel
