Live data from Hacker News

Ada, its design, and the language that built the languages

iqiipi.com

181–190 of 242 posts

Re: Ada, its design, and the language that built the languages

#182

The article states, quoting: "JavaScript's module system — introduced in 2015, thirty-two years after Ada's — provides import and export but no mechanism for a type to have a specification whose representation is hidden from importers." Then: "in Ada, the implementation of a private type is not merely inaccessible, it is syntactically absent from the client's view of the world." Am I missing something -- a JavaScript…

See my comment here for an example: https://news.ycombinator.com/item?id=47810686

Re: Ada, its design, and the language that built the languages

#184
post #175

I like Ada. I can’t believe this whole discussion about how types are handled missed the entire ML family of languages. ML, Standard ML, Concurrent ML, Caml, OCaml, and more have structural types, supported and enforced by the compiler. Ada has one of the same primary issues as PL/I, PHP, and Perl. As much as one might like it, it’s a huge language with loads of syntax and semantics baked into the core language. The…

As far as I can tell you cannot create your own bounded Integer/Floating point types in any of the ML languages. That's one example of one of the core Ada type features. Most people have never experienced a type system like Ada and you will be surprised by how it helps you write higher quality software that is also more reliable.

[deleted]

Re: Ada, its design, and the language that built the languages

#185
>Ada's deployment domain meant that Ada's successes were invisible. A software project that compiles without error, runs without race conditions, and has been formally verified to satisfy its specification does not generate incident reports or post-mortems or conference talks about what went wrong. Ada's successes — the aircraft that have not crashed, the railway signalling systems that have not failed, the missile guidance software that has not misguided — are invisible precisely because they are successes.

Um... this is most certainly not true. Back in the late 1990s and early 2000s, Ada was the language of choice at my Australian university for both computer science and software engineering degrees.

I distinctly recall my lecturer telling us a story about a fancy presentation of Ada in military tank (AFV) systems for the DoD. The story goes that during the presentation, in front of a live audience, the presenter AND the audience had to duck after the tank's turret began spinning around and around. The code had entered an infinite loop!

Re: Ada, its design, and the language that built the languages

#186
post #36

I really don't want this to be AI writing because I enjoyed it, but as other commenters have pointed out, the rate of publishing (according to the linked Twitter account) is very rapid. I'm worried that I can't tell.

> it — a crisis not of computer science but of procurement

> a subtype — not in the object-oriented sense of a type that extends another, but in the mathematical sense of a constrained set

A number of em dashes and "not X, but Y" constructs unfortunately, sometimes even right next to each other like the above.

I'm not convinced this work is wholly AI but it has at least the smell of augmentation or assistance, and a sloppy mindset in terms overseeing it. That indicates a lack of investment from the author which I always think is... unfortunate as a reader, to say the least.

Re: Ada, its design, and the language that built the languages

#187

Earlier quoted context omitted.

The ADA compiler for OpenVMS was over $200,000 in the 1990s.

Probably because only defense contractors used it. Now imagine that kind of gouging occuring for everything else they spend money on.

Ada was designed to solve different problems in harsher environments than other PLs at the time. Mostly, it was designed for the defense and aeronautics industries and had to compete against other PL designs to become a govt standard, similar to how weapons of war are developed and chosen. Think developing for hardcore code audits. There is no way the language could check all the boxes and remain compatible with, say, Pascal or Modula syntax.

Re: Ada, its design, and the language that built the languages

#188
post #51

Earlier quoted context omitted.

Mind you, that suggests that the sentence is at least half-true even if "much more complex" is a big overstatement, since Rust, "modern" C++ and the later evolutions of C# are all relatively recent. (What would have compared to Ada in complexity back in the day? Common Lisp, Algol 68?) As a matter of general interest, what features or elements of Ada make it particularly hard to compile, or compile well? (And are the…

You're right in your first part. Ada 83 is less complex than modern C++ or Rust. However Ada kept evolving, and a lot of complexity was added in later revisions, such as Ada 95, which added a kind of bastardized and very complex Java style object model layer. Ada features that are hard to compile are very common in the language. It is generally a language that is hard to compile to efficient code, because rules were…

And despite all that complexity, you make it work very well (I've used GNAT since about 2002).

Re: Ada, its design, and the language that built the languages

#189
post #175

I like Ada. I can’t believe this whole discussion about how types are handled missed the entire ML family of languages. ML, Standard ML, Concurrent ML, Caml, OCaml, and more have structural types, supported and enforced by the compiler. Ada has one of the same primary issues as PL/I, PHP, and Perl. As much as one might like it, it’s a huge language with loads of syntax and semantics baked into the core language. The…

As far as I can tell you cannot create your own bounded Integer/Floating point types in any of the ML languages. That's one example of one of the core Ada type features. Most people have never experienced a type system like Ada and you will be surprised by how it helps you write higher quality software that is also more reliable.

F# has units, does it not support bounds on those units?

Re: Ada, its design, and the language that built the languages

#190

Ada was also ignored because the typical compiler cost tens of thousands of dollars. No open source or free compiler existed during the decades where popular languages could be had for free. I think that is the biggest factor of all.

This. Nothing can compete with free.

There were effectively no free compilers in the 80s. If you had an expensive UNIX workstation it might come with one, but everyone in the micro world had to pay. Or they wrote in Assembly or a BASIC interpreter.

Granted, some were pretty cheap, at least by the early 90s.

Post reply on HN