IMHO, inheritance is quickly becoming _near_ to obsolete (not totally
obsolete, just near to it).  For years it was the rage, but it seems to
me that good OO design really should emphasize the HAS-A relationship,
not the IS-A.

I have seen a lot of systems with an overabundance of inheritance, and
all it has done is make the system harder to understand and maintain,
and the bugs harder to track down.  When I see a system that uses MI or
a great deal of inheritance in general, it speaks to me of a refactoring
opportunity.  (In fact, I can't remember the last time that I saw a good
use of MI.)  When those C++ guys bring it up, I would question them on
their overall design goals.  MI is really just an escape route.

However, what I do like is the concept of an interface -- a promise to
answer certain questions.  If I look at myself as an object in an OO
system, I would see a Person who is a Father, a Husband, an Employee, a
Son, etc.  That may speak of MI.  But, I rather like to look at it as 'I
answer certain questions per the role I am currently playing'.  This is
accomplished through the contracts of the interfaces, and perhaps (in
implementation) as adaptors on Person.

Sorry for spouting so much.

=jason
[:question | ^One] 

  >  -----Original Message-----
  >  From: squeak-dev-admin at lists.squeakfoundation.org 
  >  [mailto:squeak-dev-admin at lists.squeakfoundation.org] On 
  >  Behalf Of Karl Ramberg
  >  Sent: Friday, October 11, 2002 3:24 PM
  >  To: squeak-dev at lists.squeakfoundation.org
  >  Subject: Re: is Missing multiple inheritance in sqeak a drawback ?
  >  
  >  
  >  
  >  
  >  Hans Beck wrote:
  >  > 
  >  > Hi,
  >  > 
  >  > I'm using squeak for prototyping our LCD measurement 
  >  system software.  
  >  > From time to time, some colleagues look at my display and are 
  >  > astonished ;-)) But they are c++ freaks, and if we 
  >  discuss about the 
  >  > usability  of squeak for prototyping, always there comes 
  >  the argument 
  >  > of lacking multiple inheritance.
  >  > 
  >  > So because I'm not a theoretican for computer languages 
  >  but  I suppose 
  >  > there are a lot very good guys on this list, I would ask the 
  >  > community, how far multiple inheritance is really 
  >  needed, or is it bad 
  >  > or what ever ? (Looking from a more or less theoretical 
  >  viewpoint of 
  >  > object oriented concepts ) ?
  >  
  >  Take a look at this:	
  >  http://www.unicavia.com/Squeak/MultipleInheritanceInST80.html
  >  
  >  Karl
  >  
  >  
  >  
  >  ---
  >  Incoming mail is certified Virus Free.
  >  Checked by AVG anti-virus system (http://www.grisoft.com).
  >  Version: 6.0.384 / Virus Database: 216 - Release Date: 8/21/2002
  >   
  >  

---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.384 / Virus Database: 216 - Release Date: 8/21/2002