Path: utzoo!attcan!uunet!lll-winken!lll-tis!mordor!joyce!ames!nrl-cmf!ukma!rutgers!att!cuuxb!mmengel
From: mmengel@cuuxb.ATT.COM (~XT4103000~Marc Mengel~C25~G25~6184~)
Newsgroups: comp.lang.misc
Subject: Object Oriented vs. Overloaded
Keywords: sloppy code, overload, object oriented, ada, c++, smalltalk
Message-ID: <2058@cuuxb.ATT.COM>
Date: 12 Sep 88 19:29:15 GMT
Reply-To: mmengel@cuuxb.UUCP (Marc W. Mengel)
Organization: AT&T, Data Systems Division, Lisle, IL
Lines: 47

In article <2854@utah-gr.UUCP> u-jleigh%sundial.utah.edu.UUCP@utah-gr.UUCP (Jason Leigh) writes:
>I do not agree with your notion that using a '+' to concat two strings
>causes 'sloppy' code.  Such an allowance is called 'overloading' which
>is a concept availabe on most modern object oriented programming languages
>such as Ada and C++.  The purpose of overloading is to enhance the 
>readability of code by hiding as much unnecessary information as possible.
>I am surprised that after having written an Ada compiler, you never came
>across overloading...

Overloading is NOT equivalent to object oriented programming.  Object oriented
programming is a paradigm which *can* be used in *most* programming languages.
(a variation on "Real programmers can write FORTRAN in any language...")

Overloading when taken to the extreme creates a program that the author
can read, but nobody else can.  If you have to walk in cold and read

	mytype a,b,c;

	foo()
	{
		a = a + b;
		a++;
		c = c - a;
	}

and guess that a, b, and c are vectors of linked lists, and "+" involves
an O(n**2) combinatorial mixture of the two operands; the code is not
clear.  (sure you can document it with comments, etc.  but the problem
is that you can also *not* document it...).  It is even more confusing
if the "-" operation is unrelated to the "+" operation, etc.  It may make
perfect sense to the author, but some poor sod who gets hired to maintain
the code 5 years later when a bug is discovered has to learn someone else's
notation in order to make sense of the code.

Smalltalk is the only language I know of that *forces* you to operate within
the Object Oriented paradigm.  C++ allows some syntactic sugar on the front
of C, but not much else (There are many who disagree on this point -- flames
to me, not the net).  Ada doesn't really provide any concept of classes,
sub-classes or inheritance, so it doesn't have many built-in's for Object
Oriented programming, although you can construct such a system.

>Jason Leigh

-- 
 Marc Mengel			       
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