On 31 March 2011 22:03, Stéphane Ducasse <[email protected]> wrote: >>> >> >> Stef, >> >> I'm sure you really miss last year, but we're entering the second quarter of >> 2011 ;-) >> >> []s >> >> Getting back to the technical part of your post, I also always tried to >> understand why in some cases we end up with this strange hierarchy > > people long time ago thought that inheritance = reuse. >
It is strange, because i learned that inheritance is _specialization_. And i actually haven't took much care about subtleties of this, before i met smalltalk and start coding in it. It is in smalltalk, where it become apparent to me: - subclassing is not a way to "extend" a superclass, it is a way to specialize a superclass. >> (which you mock saying Car inherits from Wheel), specially if we take in >> account Smalltalk is a single inheritance language, so you have only a shot >> to specialize a given class. >> >> Maybe the folks that did it in the past were less used to composing than >> inheriting and the second way saves writing some new methods to avoid >> breaking the Demeter principle? > > I'm quite sure that LOD was not their concern. >> >> Perhaps understanding the "crucial incident" could lead us to better >> roadmap. . . > > No. We know design. We should just implement it. > > Stef > -- Best regards, Igor Stasenko AKA sig.
