On Tue, Aug 6, 2013 at 2:58 PM, BrJohan <brjo...@gmail.com> wrote: > On 06/08/2013 11:30, Chris Angelico wrote: >> >> On Tue, Aug 6, 2013 at 10:10 AM, BrJohan <brjo...@gmail.com> wrote: >>> >>> Now, I want to create instances of the correct subclasstype as decided by >>> the common baseclass, like this: >>> >>> i = Sup(args_allowing_the_baseclass_to_deduce_correct_subclass) >>> >>> where i can be of any class except Sup itself (as decided by Sup) >> >> >> Can you do this as a factory function instead of the class itself? >> Then all you need to do is call the appropriate class. >> >> ChrisA >> > > My classhierarchy is like a multilevel tree where each non-leaf node (class) > is given knowledge about its nearest subclasses and their 'capacities'. > > So, my idea is to let the 'upper' class recursively choose which of its > nearest subclasses is the 'correct' one, until approaching a 'leaf' class > from which the instance should be created. And, given my knowledge that a > solution along the lines of this idea has been designed and was working, I'm > still hopeful ... (or I'll have to investigate all those old backup-DVDs)
[ responding on-list - I hope it was mere oversight that had this come privately to me alone ] This is code smell; this recursive search for the "right" class seems likely to be wrong. Can you have the classes perhaps register themselves in some way? On what basis is a superclass to determine that one of its subclasses should handle this request? ChrisA -- http://mail.python.org/mailman/listinfo/python-list
