On Nov 24, 2009, at 3:30 PM, Sean Owen wrote: > I'm willing to be convinced but what is the theoretical argument for this?
See the Lucene archives: http://search.lucidimagination.com. There has been a lot of discussion on it. And I mean a lot. And then some. :-) Search for anything on interfaces, abstract classes or back compatibility. > > I am all for interfaces *and* abstract classes. You write the API in > terms of interfaces for maximum flexibility. You provide abstract > partial implementations for convenience. Everyone is happy. I agree. > > The best argument I've seen against it is that it can be overkill. In > super-performance-critical situations the dynamic dispatch overhead is > perhaps worth thinking about, but that's rare. What else? > > I take the point about interfaces changing, but this is significant > when you expect a lot of third-party implementers of your interfaces. > I don't think that is true here. I disagree here. In open source, you never know where the next good idea is coming from. We should just always assume they will change. > > On Tue, Nov 24, 2009 at 8:08 PM, Ted Dunning <ted.dunn...@gmail.com> wrote: >> Yes. Interfaces are the problem that commons math have boxed themselves in >> with. The Hadoop crew (especially Doug C) are adamant about using as few >> interfaces as possible except as mixin signals and only in cases where the >> interface really is going to be very, very stable. >> >> Our vector interfaces are definitely not going to be that stable for quite a >> while. >> >> On Tue, Nov 24, 2009 at 12:03 PM, Jake Mannix <jake.man...@gmail.com> wrote: >> >>> Well we do use AbstractVector. Are you suggesting that we *not* have a >>> Vector interface >>> at all, and *only* have an abstract base class? Similarly for Matrix? >>> >>> -jake >>> >>> On Tue, Nov 24, 2009 at 11:57 AM, Ted Dunning <ted.dunn...@gmail.com> >>> wrote: >>> >>>> We should use abstract classes almost everywhere instead of interfaces to >>>> ease backward compatibility issues with user written extensions to >>> Vectors >>>> and Matrices. >>>> >>>> On Tue, Nov 24, 2009 at 9:38 AM, Grant Ingersoll (JIRA) <j...@apache.org >>>>> wrote: >>>> >>>>> It seems like there is still some commonality between the two >>>>> implementations (size, cardinality, etc.) that I think it would be >>>>> worthwhile to keep SparseVector as an abstract class which the other >>> two >>>>> extend. >>>>> >>>> >>>> >>>> >>>> -- >>>> Ted Dunning, CTO >>>> DeepDyve >>>> >>> >> >> >> >> -- >> Ted Dunning, CTO >> DeepDyve >> -------------------------- Grant Ingersoll http://www.lucidimagination.com/ Search the Lucene ecosystem (Lucene/Solr/Nutch/Mahout/Tika/Droids) using Solr/Lucene: http://www.lucidimagination.com/search
