From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED.fn3LatRFkm9/xzEj7F2/NQ.user.gioia.aioe.org!not-for-mail From: "Dmitry A. Kazakov" Newsgroups: comp.lang.ada Subject: Re: Ada in command / control systems Date: Fri, 1 Mar 2019 11:46:23 +0100 Organization: Aioe.org NNTP Server Message-ID: References: <2199b15b-d704-403f-a6c4-00fab29792d5@googlegroups.com> <72738cc8-3f65-4cc1-8c61-b1166cb5e3c2@googlegroups.com> <9807ec3a-4c34-4641-acfa-e9cf22de95ce@googlegroups.com> <51611452-1f49-4d8d-b93d-363cbbee29d0@googlegroups.com> NNTP-Posting-Host: fn3LatRFkm9/xzEj7F2/NQ.user.gioia.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 Content-Language: en-US X-Notice: Filtered by postfilter v. 0.9.2 Xref: reader01.eternal-september.org comp.lang.ada:55730 Date: 2019-03-01T11:46:23+01:00 List-Id: On 2019-03-01 10:22, Maciej Sobczak wrote: >> How would I pass a complex input to a block, a matrix, user credentials? > > I think it has aggregate signals (or buses), even with multiple levels of nesting. That is, what looks like a single line on the screen can be an aggregate of multiple values, even other aggregates. The problem is with the operations. You might be able to aggregate but not operate these aggregates as entities of the corresponding semantics. And of course there is an even larger problem on the horizon: the code generator. You need to put down and numerically solve a system of differential equations corresponding to the diagram. Once you let user-defined stuff in, you risk a situation when there would be no corresponding system of equations or no solution of the system. Simulink, wisely, does not attempt to resolve this. It admits defeat allowing so-called s-functions: a piece of code written in a *sane* language that implements what Simulink cannot (more or less everything). So much for modeling... >> The problem is software decomposition and reuse. Simulink's is an ultra >> low-level language, lower than assembler, IMO. > > Then let's stop talking about Simulink. Since the beginning, I'm stressing that it's not Simulink vs. Ada, it's rather MBD vs. source code. That is, don't argue that MBD does not work just because Simulink does not have your pet feature. Simulink is an example of why this does not work on larger scale. You can have a small subcomponent in Simulink, but all falls apart once you move to larger components and their interplay. My suspicion is that there cannot be such thing as a unified model language, in some strong fundamental way. >> You mean Simulink has a better diagnostics? > > You have complained that it crashed after you have hacked its files by hand. Well, I can imagine that some of its later versions might not crash after such abuse. Or that some other tool would not crash. If your argument against MBD depends on some particular tool version crashing, then it's a poor argument. I have crashed compilers, too. Yes, but you do not start patching the object code. Assembler insertions are extremely rare. s-functions is a norm, you have to break out of the model abstraction and write a lot around it in order to make that puny model work. >> They can keep on inventing more and more bizarre forms of "non-code" to >> write, that will not make it work. > > Then they will keep inventing. Compilers, libraries and frameworks are now free, which makes them kind of hobby thing. There is no business incentive to come back to source code, so companies will do their best to keep us from writing it. There is no any business involved because the software product itself is "free". But there is a strong trend to end this. Companies cannot claim software free of any liability anymore. Even giants like Facebook and Amazon get charged. I don't know how the industry is going to refund these new liabilities. At some point they will have to and the pyramid will collapse. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de