Re: Ada95 for Windows 95 Reviewers Wanted

[Ted Dennison <dennison@escmail.orl.mmc.com>]

Jere W. Retzer wrote:
> 
> Two of the advantages of Ada being its readability and portability, I would

Any language's portability ENDS when you venture out of the defined
language and into the OS. Ada is no different here.

> be interested in what people think of the readability of windows Ada code.
> My first reaction to the win32 bindings code I have seen is that it is
> difficult to read, but I am admittedly new.  Also, what happens to

Your first reaction would be correct in this case. Any Ada code that 
makes heavy use of thin OS bindings is ugly, and generally tough to
follow. GUI code is particularly heinous. (Note that I don't say "C" 
bindings. In Win32's case, they are technically Pascal bindings.)

That's why I tend to write thick bindings whenever I'm going to use a
significant amount of OS bindings.

> portability in general when the program is targeted to an environment that
> requires bindings?  For that matter, will we have portability problems if we
> use bindings from different vendors as implied above?  Are these two
> attributes affected by the 'thickness' of the binding as it is being
> discussed here?

1 - It goes out the window. 
2 - Yes.
3 - Somewhat.

3 deserves a more detailed answer. Yes, any "thick" bindings you have
will probably be completely different when you switch vendors (assuming 
your vendors even give you thick bindings). However, the difference in
vendor's thin bindings is likely to be something that will require minor
changes to EVERY binding call. And with thin binding there are a LOT of
calls.

Also, note that if you write your own thick bindings, you will have the
ability to make the nessecary changes in only the body of the bindings 
packages when you change vendors. This significantly reduces the impact.

-- 
T.E.D.          
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