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Airbus Chooses GNAT Pro Ada for Development of Unmanned Aerial System

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Re: Airbus Chooses GNAT Pro Ada for Development of Unmanned Aerial System

#151

Post by foerbert »

sai_c wrote: post #65
_1gwx wrote: post #6

Not an expert in ADA, but after playing around with it for a while, I don't know why this language doesn't get more praise. It seems to solve a lot of the memory problems Rust solves, albeit in a different way. Its first-class arrays and strong type system seem to go a long way into not having to deal with pointers often, for example. These "features" today would likely be considered part of "a better C", except that…

Because Ada is not a language for quick and dirty. It's a language that is only fun and usable if you apply engineering methods to the whole project (a.k.a requirements, documentation etc.). Most projects out there don't. Quite frankly, it's not a hackers language. EDIT: Oh and the price tag.

It's in gcc. Or available from AdaCore under GPL-3 (yeah, I know). Unless you're in the sort of position where you need a support contract anyway, price isn't really an issue.

Re: Airbus Chooses GNAT Pro Ada for Development of Unmanned Aerial System

#152

Post by EdPF »

geofft wrote: post #142
Rochus wrote: post #77

Earlier quoted context omitted.

Yes, thanks. There are a lot more examples. I wish someone with deep knowledge and real experience in both Ada and Rust would write a side-by-side comparison covering all relevant aspects, including more recent developments like https://www.adacore.com/papers/safe-dynamic-memory-managemen... .

I've seen that before - is there an implementation, and also, how do the usual users of Ada feel about it? I feel like one of the attractions to Ada for this sort of use case is its maturity, and "here's a proposal for a complicated feature, inspired by Rust, a language which young and rapidly evolving and in particular switched to a new borrow checker implementation less than two years ago and shipped it with known…

There's a telegram group https://t.me/ada_lang you could open that question on. Also, there's work (I think on GitLab) on a package manager called Alire. And the very old standby comp.lang.ada which tends to have some interesting conversations.

Re: Airbus Chooses GNAT Pro Ada for Development of Unmanned Aerial System

#153

Post by EdPF »

geofft wrote: post #142
Rochus wrote: post #77

Earlier quoted context omitted.

Yes, thanks. There are a lot more examples. I wish someone with deep knowledge and real experience in both Ada and Rust would write a side-by-side comparison covering all relevant aspects, including more recent developments like https://www.adacore.com/papers/safe-dynamic-memory-managemen... .

I've seen that before - is there an implementation, and also, how do the usual users of Ada feel about it? I feel like one of the attractions to Ada for this sort of use case is its maturity, and "here's a proposal for a complicated feature, inspired by Rust, a language which young and rapidly evolving and in particular switched to a new borrow checker implementation less than two years ago and shipped it with known…

Whoops, forgot. The borrow checking memory management is available on GNAT Community Edition 2020, for SPARK and (I believe) also Ada itself. The GNAT Ada compiler is used to compile and build SPARK apps. Since SPARK is very strict, the implementation is robust even at this relatively early stage.

Re: Airbus Chooses GNAT Pro Ada for Development of Unmanned Aerial System

#154

Post by igouy »

protomyth wrote: post #148
igouy wrote: post #146

Earlier quoted context omitted.

March 7, 1988 — "Smalltalk/V 286 is available now and costs $199.95, the company said. Registered users of Digitalk's Smalltalk/V can upgrade for $75 until June 1." https://books.google.com/books?id=CD8EAAAAMBAJ&lpg=PA25&ots=...

which quickly became Visual Smalltalk Enterprise, which you can ask various companies about how that went commercially.

Factually, October 22 1989 — "… an OS/2 version of the Smalltalk language, Smalltalk V/PM … The $500 product is designed to cut the time it takes to prototype user-interface-intensive applications for Presentation Manager."

https://www.cbronline.com/news/digitalk_has_first_compiled_v...

Re: Airbus Chooses GNAT Pro Ada for Development of Unmanned Aerial System

#155

Post by foerbert »

Rochus wrote: post #122
7thaccount wrote: post #111

Earlier quoted context omitted.

Thank you! Is the FSF GNAT version ancient or pretty close to the Adacore version in terms of updates?

I'm not up to date. Last time I checked (about five years ago) the FSF GNAT was about a year behind AdaCore GPL GNAT. Maybe someone else has more recent information.

At least as of a year or two ago, AdaCore seemed to be putting in more effort to shore up the differences between FSF and GPL GNAT.

Re: Airbus Chooses GNAT Pro Ada for Development of Unmanned Aerial System

#156

Post by Jtsummers »

p_l wrote: post #147
Jtsummers wrote: post #18

Earlier quoted context omitted.

It hasn't been a requirement for a long time, though it is used in some DOD projects still.

Last I heard, the first major project that had blanket allowance to not use Ada was F-35... ... And I honestly don't think it benefitted from that exception ;)

That's still 20 years, and the mandate wasn't terribly successful. Lots of systems from the late 80s and 90s were developed in non-Ada languages, including new development (not just continuations of older systems). Now, whole platforms, that was probably harder to move away from the mandate until later. But components could be and were developed in other languages.

Re: Airbus Chooses GNAT Pro Ada for Development of Unmanned Aerial System

#158

Post by foerbert »

geofft wrote: post #64
_1gwx wrote: post #6

Not an expert in ADA, but after playing around with it for a while, I don't know why this language doesn't get more praise. It seems to solve a lot of the memory problems Rust solves, albeit in a different way. Its first-class arrays and strong type system seem to go a long way into not having to deal with pointers often, for example. These "features" today would likely be considered part of "a better C", except that…

Ada doesn't have compile-time-safe dynamic memory allocation and deallocation (i.e., tracking a pointer so that you know statically that it's no longer used elsewhere in the function that frees it). Rust does it through the lifetime system, which is based on Cyclone, which long postdates Ada. The usual alternatives are to statically allocate all your memory, to convince yourself it's safe to use Unchecked_Deallocatio…

I'm not super knowledgeable about Rust, but I have tried poking at it a few times, so... you know.

Rust seems to be extremely focused on memory safety. Meanwhile Ada is much more focused on correctness in general. Restricting the discussion to simply memory safety ignores, well, most of anything that might be programmed.

Ada also has more memory safety options than people tend to talk about. As others have mentioned, it's possible to allocate quite a bit on the stack. Other rules also prevent some reference issues.

One thing I rarely see mentioned are memory pools and subpools. It is possible to ensure whole types are allocated in a particular subpool, and deallocation can be left for when the subpool falls out of scope.

Re: Airbus Chooses GNAT Pro Ada for Development of Unmanned Aerial System

#159

Post by EdPF »

non-entity wrote: post #30
yjftsjthsd-h wrote: post #23

Earlier quoted context omitted.

Honestly, I wonder why Pascal doesn't dominate, too. Safer than C while still just as powerful, "teaching language" (easy to learn) but used for serious software (as you note, Apple used it for system programming). FPC is amazingly feature rich.

> "teaching language" (easy to learn) I think that worked against it as well.

The thing I saw with Pascal in the late 70's / early 80's was that in order to handle industrial use cases, each computer company invented its own dialect (I worked on one at Burroughs).

That was one of the problems Ada addressed. But its initial problem was the cost of compilation and builds on the hardware of the time. That got sorted out by the end of the 80's, but then other factors like contractors not wanting their customer telling them how to do their work came into play. Sort of a confusion of requirements and implementation methods.

Re: Airbus Chooses GNAT Pro Ada for Development of Unmanned Aerial System

#160

Post by sbuttgereit »

goatinaboat wrote: post #59
svvcfb1212 wrote: post #15

Earlier quoted context omitted.

Ada, not ADA. It’s named after Ada Lovelace, not an abbreviation.

The core of Oracles PL/SQL is called DIANA, distributed intermediate annotated notation (for) Ada.

And while I'm not too sure of the development history behind PostgreSQL's PL/pgSQL (I suspect Oracle's PL/SQL had influence), the Ada influence necessarily shows there as well.
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