I'm missing SPARK, the restricted and formally defined language based on Ada, extending Ada with contracts and aspects, and disallowing the insecure parts.
https://en.wikipedia.org/wiki/SPARK_(programming_language)
This is the real highlight of Ada.
Why Ada Is the Language You Want to Be Programming Your Systems With
111–120 of 330 posts
Re: Why Ada Is the Language You Want to Be Programming Your Systems With
#112Earlier quoted context omitted.
Because they overlap almost entiely in use case?
From my own analysis, about a year ago, I do not believe this to be true. Rust is memory safe, but it does not offer the type system that Ada does. The type system is where a large portion of Ada's safety comes from. They're both tackling software/system safety, but from different directions and to different ends. Additionally, modern Ada (after the introduction of SPARK, what 15 years ago now?) offers even more safe…
Hmm on further investigation I think most of the use cases I'd have for contracts are met by the borrow checker. Side effects are going to get wrapped in unsafe or be explicit in the function signature.
Re: Why Ada Is the Language You Want to Be Programming Your Systems With
#113Earlier quoted context omitted.
I understand what you're getting at here I tbink, but one of the ecosystem challenges we run into is that while Rust is abstractly a fantastic choice for the domain of systems development that would often be served by Ada (in fact we think it's a lot better in some respects because we can do more statically ahead of time, that Ada does dynamically at runtime, by abusing the Rust type system and borrow-checker), the R…
> ore attention provided to things like Wasm than there is to things like embedded use cases for example. Things might be better, but last time I checked rust's compiler was a lot slower than C and the binaries were several times bigger. That last one is a big deal for embedded.
Another consideration: Rust’s compiler is also slower because it does a lot more forces you to add error handling.
In terms of real impact on developers I never felt it was dramatic. The rust language support in editors is so good that you will catch most errors before compiling. So once everything is dealt with you usually compile and it just works.
Binary size is also one of these areas they are dealing with atm.
Re: Why Ada Is the Language You Want to Be Programming Your Systems With
#114> Ada code controls rockets like the Ariane 4 and 5, many satellites, and countless other systems where small glitches can have major consequences. A somewhat amusing endorsement given that the infamous failure of the maiden launch of the Ariane 5 due to series of interconnected software bugs - a reminder perhaps that the choice of implementation language does not automatically make for a reliable system.
A language doesn't make code automatically reliable, but it can certainly help. Ada can do overflow checking, so choice of language can have an impact on reliability, but the software engineers deliberately disabled some of those checks to save CPU cycles on a computer that was running at/near capacity. Their reasoning was that it was impossible for the variables in question to overflow given the known flight charact…
This is why I always document considerations like these with stuff like: “This error case can’t happen because foo” or even better, enforce these things by type system and let the compiler decide if it really can’t happen once you changed something in the other part of the code.
Re: Why Ada Is the Language You Want to Be Programming Your Systems With
#115This article promotes a popular misconception of the programming situation for defense projects in the 1970s. There may have been "hundreds of specialized programming languages" in existence that could be used, but just a handful actually predominated. Most aeronautical projects were done in JOVIAL. I've talked about this history with engineers from the 1960s-70s. They did not regard the introduction of Ada as a good…
As I've probably posted before, I was at a Dijkstra lecture in the early 80s where he put up one of his famous hand-drawn slides that said "Ada: The latest government boondoggle that will take 5 years and 5 million dollars to kill." [5 million dollars was a lot of money back then.] So yeah, even the academics didn't much care for Ada.
Re: Why Ada Is the Language You Want to Be Programming Your Systems With
#116First, this is a great introduction article to Ada. It's a great history lesson, and analysis of where it's used and why. That said, it seems to be arguing for something in a vacuum. Where is the mention of other new programming languages that also fit this category? Where is the mention of Rust? Rust fits all the same requirements: - A general, flexible design that adapts to satisfy the needs of embedded computer ap…
> - Easy to implement the language specification. All features should be easy to understand. I'm not sure this is at all applicable to rust. Perhaps once there are more than the one, quickly mutating, implementation, we can say that it's easy to implement the specification. > - Reliability. The language should aid the design and development of reliable programs. This one feels a touch questionable, given the built-in…
> given the built-in "succeed or die" macros that simplify code at the cost of reliability.
I would consider a program that dies early to be more reliable (but less robust) than one that just soldiers on, probably doing wrong (and possibly dangerous) things.
Regardless, it is the programmers choice whether to call panic!() or to try to handle an error gracefully and continue.
Re: Why Ada Is the Language You Want to Be Programming Your Systems With
#117Earlier quoted context omitted.
The situation hasn't changed, ESR just flat-out never had a good read on Ada. You really cannot take the Jargon file seriously, its author's ignorances are glaring and numerous. Ada's "elphantine bulk" is smaller than many modern languages, and even some which the Jargon File praises, like Common Lisp. Its inter-process communication and exception handling functionality were relatively forward-thinking at the time an…
The kindest thing one can say about esr is that he is not as clever as he thinks he is.
Which is also the least kind thing.
Re: Why Ada Is the Language You Want to Be Programming Your Systems With
#118Earlier quoted context omitted.
In this discussion, Rust is actually relevant, nearest comparison I can think of. It's not necessarily as much Rust as the desperate need to get something safer than C/C++ without compromising performance and interoperability.
>as the desperate need to get something safer than C/C++ without compromising performance and interoperability Object Pascal D ATS Common Lisp Ada even Fortran!! the list can go on and on
I think the fact that all of those have been around for decades, and yet haven't gained much traction, implies that there's something wrong with them that makes them unsuitable.
If it's just a matter of marketing and failing the subjectivity of a popularity contest, that's a shame, but I wouldn't leap to assume that's the sole reason.
Re: Why Ada Is the Language You Want to Be Programming Your Systems With
#119This article promotes a popular misconception of the programming situation for defense projects in the 1970s. There may have been "hundreds of specialized programming languages" in existence that could be used, but just a handful actually predominated. Most aeronautical projects were done in JOVIAL. I've talked about this history with engineers from the 1960s-70s. They did not regard the introduction of Ada as a good…
Seems like "the next big thing" has existed in the tech world from the start. I remember using Ada 95 in university, after learning C++, Java and Python in other projects. It worked very well for concurrent processes, but it was so basic as a developer experience. In C++ (98 I think) I needed to build length dynamic arrays, in Ada 95 I had to build dynamic length strings .
> in Ada 95 I had to build dynamic length strings.
Ada95 did have dynamic strings, they were provided by Ada.Strings.Unbounded package.
Re: Why Ada Is the Language You Want to Be Programming Your Systems With
#120If you've done VHDL, you'll be familiar with Ada's syntax. When the DoD commissioned the design of VHDL, they required that its syntax be based on Ada. https://en.wikipedia.org/wiki/VHDL#History
Also if you've written any PL/SQL stored procedures in Oracle.
PL/SQL has remained faithful to the Ada zeitgeist. I've found spotting flaws in PL/SQL during peer review to be easier than some other languages.