[Paul] > > Aside: While I am at it, let me reiterate what I have said to the > > other developers privately: there is NO value to inheriting from the > > array class. Don't try to achieve that capability if it costs > > anything, even just effort, because it buys you nothing. Those of you > > who keep remarking on this as if it would simply haven't thought it > > through IMHO. It sounds so intellectually appealing that David Ascher > > and I had a version of Numeric that almost did it before we realized > > our folly.
[Travis] > I appreciate some of what Paul is saying here, but I'm not fully > convinced that this is still true with Python 2.2 and up new-style > c-types. The concerns seem to be over the fact that you have to > re-implement everything in the sub-class because the base-class will > always return one of its objects instead of a sub-class object. > It seems to me, however, that if the C methods use the object type > alloc function when creating new objects then some of this problem is > avoided (i.e. if the method is called with a sub-class type passed in, > then a sub-class type gets set). This would severely constrain the __new__ method of the subclass. > Have you looked at how Python now allows sub-classing in C? I'm not an > expert here, but it seems like a lot of the problems you were discussing > have been ameliorated. There are probably still issues, but.... > > I will know more when I seen what happens with a Matrix Object > inheriting from a Python C-array object. And why would a Matrix need to inherit from a C-array? Wouldn't it make more sense from an OO POV for the Matrix to *have* a C-array without *being* one? > I'm wondering if anyone else with more knowledge about new-style c-types > could help here and show me the error of my thinking. I'm trying... -- --Guido van Rossum (home page: http://www.python.org/~guido/) _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com