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

Post by sa46 » Sat, Apr 18, 2026, 3:15 AM UTC

init1 wrote: post #178

hackrmn wrote: post #136

I find multiple "strange" flaws with the article, even for my appreciation of Ada _and_ the article as an essay: * The article claims only Ada has true separation of implementation vs specification (the interface), but as far as I am able to reason, also e.g. JavaScript is perfectly able to define "private" elements (not exported by an ES6 module) while being usable in the module that declares them -- if this isn't "…

> The article claims only Ada has true separation of implementation vs specification (the interface), but as far as I am able to reason, also e.g. JavaScript is perfectly able to define "private" elements (not exported by an ES6 module) while being usable in the module that declares them -- if this isn't "syntactical" (and semantical) separation like what is prescribed to Ada, what is the difference(s) the article tr…

Post by OneWingedShark » Sat, Apr 18, 2026, 3:23 AM UTC

ako wrote: post #152

jll29 wrote: post #106

Earlier quoted context omitted.

I have not seen it, but there is something close to what you ask about: Turbo Modula-2 (an implementation of MODULA-2 written by Martin Odersky), as both MODULA-2 and PASCAL were Niklaus Wirth-invented languages that looks very similar to Ada: "Shortly before we finished our compiler, Borland came out with Turbo Pascal, and they were considering going into the Modula-2 market as well. In fact, Borland decided to buy…

I think Oracle PlSQL was also based on Ada, basically Ada + SQL embedded. So it may be the widest used version of "Ada".

Post by OneWingedShark » Sat, Apr 18, 2026, 3:53 AM UTC

mcdonje wrote: post #68

donatj wrote: post #41

I like the article overall but the continually repeated 'Language X didn't have that until ' is very grating after the first ten or so. I also wish there were concrete code examples. Show me what you are talking about rather than just telling me how great it is. Put some side by side comparisons!

I imagine an ada dev would find the pattern grating over the decades, so it reads like an expression of that experience.

    Generic
      Type Index   is ();                                      -- Any discrete type.
      Type Element is limited private;                           -- Any non-discriminated type.
      Type Vector  is array(index range ) of element;          -- An array-type of Element, indexed by Index.
      with Function "="(Left, Right: Element) return Boolean ; -- Equal, defaulted.
      with Function "; -- Less-than, defaulted.
    Function Generic_Sort( X : Vector ) return Vector;

    Function Sort is new Generic_Sort( Index => Integer, Element => Integer, Vector => Integer_Array, " ">");

Post by OneWingedShark » Sat, Apr 18, 2026, 4:06 AM UTC

phplovesong wrote: post #59

I would never work on projects that ADA is used for. 1. Would never work on "missile tech" or other "kills people" tech. 2. Would never work for (civ) aircraft tech, as i would probably burn out for the stress of messing something up and having a airplane crash. That said, im sure its also used for stuff that does not kill people, or does not have a high stress level.

Post by hackrmn » Sat, Apr 18, 2026, 8:26 AM UTC

wrs wrote: post #174

hackrmn wrote: post #142

Earlier quoted context omitted.

* only if `x` is _an object_ (read: has methods) To preempt the obvious: yes, I know _everything_ (nearly) in JavaScript is an object, but a module exporting a `Function` can expect the caller to use the function, not enumerate it for methods. And the function can use a declaration in the module that wasn't exported, with the caller none the wiser about it.

I think you're confusing values with types. JS modules can certainly keep a value private, but there's no way for them to expose an opaque type , because that concept simply doesn't exist in JS. The language only has a few types, and you don't get to make more of them. TypeScript adds a lot of type mechanism on top, but because it's restricted to being strippable from the actual JS code, it doesn't fundamentally chan…

    class Age {
        #value;
        constructor(value) {
            if(typeof value != "number") throw new Error("Not a number");
            this.#value = value;
        }
    }