From: Tim Hochberg <tim.hochberg@...>
Date: 2001-08-15T01:30:29+09:00
Subject: [ruby-talk:19705] Re: Perl/Python/Ruby common backend (Parrot, can Ruby play too?)


"Andrew Dalke" <dalke@acm.org> wrote in message
news:9kpeft$kbm$1@slb4.atl.mindspring.net...
[snip]
> I learned a couple weeks ago of a reason to be able to add new
> methods dynamically.  I was at a talk where the speaker presented
> a development system for non-programmers.  It allowed them to
> tweak the class definitions in-place.  She chose Tcl (with an
> object extension) over Python because Python's ability to add
> new methods is not obvious[*] and because existing instances
> are not updated with the new class definitions
>
> [*] Here are two ways - of many - that would be "obvious"
>  == 1 (backwards compatible) ==
[snip]
>  == 2 (not backwards compatible, but when I started Python
>        I thought this would work) ==
>
> class Spam:
>   def what(self):
>     print "spam"
>
> class Spam:
>   def slice(self):
>     print "sliced"

This looks kind of similar and appears to work (at the expense of slowing
down all your lookups). (1) is prettier though...:

class Spam:
   def what(self):
      print "spam"

class Spam(Spam):
   def slice(self):
      print "sliced"

-tim