Re: Ada -vs- GNAT

[Stephen Leake <stephen.a.leake.1@gsfc.nasa.gov>]

Richard Riehle <richard@adaworks.com> writes:

> <snip>    XP is a reaction to the Industrial
> Engineering model that has characterized so much software engineering
> practice.

Well, I find that Ada and XP go well together. 

As to whether having a Standard for Ada is a good thing, I think it
is. It means I can use GNAT to write and unit test code, then
recompile with DDCI for the 1750 target, with full confidence that the
language semantics is the same, and all of it is implemented.

One of the reasons I _don't_ like C++ is that I cannot do this with
confidence. On another current project, we're using Gnu C++ for unit
tests, and Green Hills for the target. We are _not_ allowed to use the
full C++ language, because neither compiler meets the standard.

> When a Standard keeps a language from meeting its full potential, is
> that a good thing. 

Standards do not limit languages; customers limit languages. That
includes me! 

GNAT is open source; if you want an Ada variant, go fund it! As Robert
keeps pointing out, that was one of the original motivations behind
producing an open source Ada compiler; people (mainly universities)
would be free to play around with the language. Yet no one has done it
yet in a serious way.

> <snip>
> So, it ACT deems it useful to add something as simply as attibutes to its
> compiler to accomplish things not pre-determined by the standard, so
> be it.

As long as there is a way to say "warn me if I deviate from the
standard", I agree with this (GNAT has such a switch, last I checked).

> This could be one of the features that differentiates their product
> from that of other compiler publishers.   

That's the Microsoft way. The true ACT way is to distinguish their
real product (which is support and service) by delivering better
quality. 

-- 
-- Stephe