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From: John Robinson <chat@jr-and-assoc.demon.co.uk>
Subject: Re: pointers & OOP
Date: 1999/05/03
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In article <m3k8uszln5.fsf@mheaney.ni.net>, Matthew Heaney
<matthew_heaney@acm.org> writes
>John Robinson <john@jr-and-assoc.demon.co.uk> writes:
>
>> It is difficult to do anything really useful with Ada 95 OOP features
>> without the use of pointers.
>
<snip>
>
>> Any collection class for example will need to use pointers, even if
>> the collection is based around a fixed length array.  
>
>Yes, a collection whose items have a class-wide type will require
>pointer use.  But you can use a smart pointer, so you don't have to
>worry about any pointer manipulation headaches.  Gives you the same as a
>reference in other OO languages.
>

I still stand by the assertion that to do a full OO application you will
need to use pointers (smart or otherwise) somewhere along the line.
Yes, you can hide the implementation detail (and you should) but you
will still need them.

I accept that one can also gain an advantage in many areas by using the
OOP features to do individual jobs (such as the use of controlled types
which Robert used as an example).  I also accept that some parts of a
system may be able to avoid pointers where other languages would need
them (such as the factory method which you described).

<snip>

>
>I don't think they'd disagree that Ada95 has better compile time
>checking.  The argument is, How important is compile-time checking to
>the programmer?  
>
>Most programmers are oblivious to the benefits of rigorous compile-time
>checking, and many programmers actually like having bugs (because they
>get to find them and fix them), so "Ada95 has better checking" is a
>tough sell.

I agree.  The software profession will only become a profession when
programmers accept that they have a job to do and are not paid to have
"fun" whilst "playing" with their bugs!


-- 
John Robinson
John Robinson & Associates
www.jr-and-assoc.demon.co.uk