----- Original Message ---- > From: Jon Lang <datawea...@gmail.com>
> > Actually, I'd prefer to go much further than this: > > > > use Core 'MyCore'; > > > > And have that override core classes lexically. > > > > That solves the "but I want it MY way" issue that many Perl and Ruby > programmers have, but they don't shoot anyone else in the foot. > > Since 'use' imports its elements into the current lexical scope, the > version-based approach can do this. > > The only catch that I can think of has to do with derived classes: > does the existence of a customized version of a class result in > same-way-customized versions of the classes that are derived from the > original class? That is, if I added an "updated" version of Foo, and > Bar has previously been defined as being derived from Foo, would I get > a default "updated version" of Bar as well? Or would I have to > explicitly update each derived class to conform to the updated base > class? I'm not sure I understand you. If 'Bar' inherits from 'Foo' and 'Foo' has extended the core Array class to lexically implement a .shuffle method, then I would expect 'Bar' to have that also. There are two things involved: 1. Liskov should be respected, when appropriate (http://www.oreillynet.com/onlamp/blog/2008/02/the_liskov_substitution_princi.html) 2. 'Bar' is coupled to 'Foo' and needs to know 'Foo's implementation (a charming anti-inheritance argument). See #1 :) Or did you mean something completely different? Note that Liskov is great, but has issues at times when composition is unclear. Cheers, Ovid -- Buy the book - http://www.oreilly.com/catalog/perlhks/ Tech blog - http://use.perl.org/~Ovid/journal/ Twitter - http://twitter.com/OvidPerl Official Perl 6 Wiki - http://www.perlfoundation.org/perl6
