Re: Ada95 OOP Questions

[cosc19z5@Bayou.UH.EDU (Spasmo)]

David Wheeler (wheeler@aphrodite.csed.ida.org) wrote:
: Andre Spiegel (spiegel@berlin.informatik.uni-stuttgart.de) wrote:
: : Spasmo writes:

[Snip]

: : With a use-clause, it looks better

: :     with Persons; use Persons;

: :     P : Person;

: :     Walk (P);
: :     Talk (P);
: :     Eat  (P);

Well since I try to avoid using a use-clause (I like the
namespace protection I get), the above really (to me) doesn't
look any better (not that the first one looked bad).  



: : > Correct me if I'm wrong on this.  So you're still passing parameters
: : > which means that data and subprograms are still 2 different entities
: : > which sorta hurts the abstraction, rather than in say C++ where 
: : > you've got a unified object.   

: : You _are_ wrong.  The subprograms actually _are_ a part of the object,
: : and they "go" with it, so to speak of, whereever you take the object.
: : It is just less obvious from the syntax in Ada.

Oh.


: Spiegel's right.  Spasmo - you're concentrating on minor syntactic variance.
: Ada treats all calls with the same syntax; C++'s syntax varies depending
: on how it's defined.  The difference is unimportant.

Well I can live with passing parameters but still the question
of inheriting operations from a parent class defined in a
different module is IMO a big deal.  I mean, I've looked at
the Lovelace tutorial and checked on this, even looked at the
OOP section in the "Core Language" section of the rationale 
(after a while I started skimming), but I've yet to see
this.  


: To see an example of OO in Ada95, look at my "Small" program at:
:   "http://lglwww.epfl.ch/Ada/Tutorials/Lovelace/small.htm"
: You'll see lots of OO concepts, and operations unified with the object.

Indeed, this is what I need to do.  I'm heading over there
right now and looking at the program.  I hope a good example
(Small is mentioned a lot) will be the thing to make me realize
just what it is I've been missing.


: --- David A. Wheeler
: Net address: dwheeler@ida.org


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