2015-06-30 11:30 GMT+02:00 Tudor Girba <[email protected]>: > What he means is that just because subclassing is available as a technical > mechanism, we should only use it for modeling subtyping and not > implementation reuse (only in very few cases this is actually useful in the > long run). >
Given how Smalltalk defines types and subtyping, I consider that subclassing should be used for implementation reuse and not for subtyping. Any Smalltalk class hierarchy which has instance variables defined in the superclass does implementation sharing/reuse. Modeling is another consideration. (I still consider the meaning of Stef phrase confusing...) > For reference, this goes under the name of Liskov substitution principle > and one nice article that explains it is this one: > http://www.objectmentor.com/resources/articles/lsp.pdf > This reference is too much into how that particular principle turns out in an ill-designed type and code sharing mechanism (C++) to be of much help ;) Thierry > > > Cheers, > Doru > > > On Tue, Jun 30, 2015 at 11:21 AM, Thierry Goubier < > [email protected]> wrote: > >> >> >> 2015-06-30 11:00 GMT+02:00 stepharo <[email protected]>: >> >>> >>>> >>> What I mean is that this is not good to have subclassing when we can use >>> subclassing. >>> >> >> Are you sure you mean that? *confused* >> >> Thierry >> > > > > -- > www.tudorgirba.com > > "Every thing has its own flow" >
