Path: utzoo!attcan!uunet!mcvax!enea!sommar
From: sommar@enea.se (Erland Sommarskog)
Newsgroups: comp.lang.misc
Subject: Re: What is B&D? (Re: Bondage and Discipline Languages)
Message-ID: <4267@enea.se>
Date: 24 Jan 89 22:45:33 GMT
Organization: ENEA DATA AB, Sweden
Lines: 37

David Gudeman (gudeman@arizona.edu) writes:
>Kevin S. Van Horn (kevin@cit-vax.Caltech.Edu) writes:
>>Give me a break!  What's so horribly difficult and inconvenient about writing
>>x.f1 when you want to use x as a variable of type t1, and x.f2 when you want
>>to use it as a variable of type t2?

Gudeman goes on with with various objections that this is "inconvenient".
Before I comment that, let me first say I find this of less interest
in this case; variant records as a mean of conversion in Pascal and 
Modula.
  Inconvenient or not - it's certainly not a good method. When you
are using x.f1 and x.f2 you are far away from the declaration and
you don't see that you are referring to the same field. And to make
it even more fun: it's compiler dependent too. Look at:
     CASE boolean OF
        true  : (ch1, ch2, ch3, ch4 : char);
        false : (int : integer);
     END;
In which order the chars are allocated is up to the compiler to decide. 

>Maybe _you_ want language designers protecting you from yourself, but
>I can get along fine without their help.  ...
>But _I_ still don't want such practices forced
>on me by my programming language.
(And lot of similar deleted.)

You may not want to be protected, and you if write code for your very
own private use, there's no problem. But if I were your boss, I'm sorry,
I'd prefer you waste some extra time and money with those small
"inconveniences" (I'm not talking variant records here, rather Ada
style or type-cast operator a la VAX-Pascal) than have to pay a lot
more money due to the mistakes you made because there was no type
checking. 
-- 
Erland Sommarskog
ENEA Data, Stockholm              This signature is not to be quoted.
sommar@enea.se