Carl Banks wrote: > Jan Theodore Galkowski wrote: >>> We've not had >>> an excellent dynamic OO language since Smalltalk, IMO. > > I would say that "excellence" in object oriented programming is not a > strong design goal of Python. Python tries to support OOP well, but > not to enhance OOP to the detriment of other, more important goals. > > [snip] >>> Guido was opposed to modifying builtin types before Java existed. It's >>> similar to his opposition to dynamic syntax. >> Opposition or not, the language definition is there. Surely Smalltalk's >> OO style can be respected. Smalltalkers have been doing OO in a dynamic >> context longer than many. There are things to learn there. > > Well, that Smalltalk and Ruby do this at least suggests that it won't > be the end of the world as we know it if it were to happen in Python. > Personally, I'm with Guido here. Allowing this might make Python's OOP > more "excellent", but it would be to the detriment of other, more > important goals, like minimizing surprise. > >> There are two things here that need to be kept straight, I think. >> >> One is the primacy of builtin types. >> >> The other is placing those builtins at the top of their own object >> hierarchy. Is "int", properly speaking, a descendent of "object"? No, >> it's the root of its own tree. > > Are you saying that it shouldn't be a descendant of "object", or that > it isn't? "int" is certainly a subclass of "object" in Python (as are > all objects). > >> Smalltalk has "int" as well, as a >> *subclass* of Number. It's primitive. > > Number is primitive? I thought all types in Smalltalk had a common > base type. > > Anyways, Python 3000 is exploring the idea of an abstract hierarchy > that has classes (interfaces?) like Number and Sequence. In fact, I > even saw some talk about somehow being able to retrofit classes to > support one of these interfaces/ABCs, though it was pretty conjectural. > >> In any case, as respectful of Mr/Dr van Rossum as I am, simply because >> so-and-so says something is bad and therefore it must be true is a >> fallacious response. > > The same could be said of Smalltalk, i.e., because Smalltalk does it > therefore it is good is just as fallacious. > > Regardless, whatever Guido pronounces is what happens. If he's > adamantly against something, it's pretty much an academic discussion. > Just to be perverse, there was an example recently where a developer asked (on python-dev) about the best way to trap and note the creation of all objects.
With a proper hierarchy, in which everything calls its parent's constructor all the way up to object, in theory (and ignoring old-style classes) it would be possible to simply modify the behaviour of object. Unfortunately this is a no-no because object's behaviour is hard-wired into the CPython interpreter. The general feeling on python-dev seems to be that this is a step too far, and that the confusion engendered by this kind of patching would not be worth the benefits gained. Certainly it appears to this reader that such a feature woudl be more abused than used. The principle of least surprise thus reigns for now. regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://del.icio.us/steve.holden Blog of Note: http://holdenweb.blogspot.com -- http://mail.python.org/mailman/listinfo/python-list
