Ada holding up F-22 Raptor upgrades
defensenews.com
defensenews.com
Now I'm not in this industry, but I know that planes these days are extremely complicated beasts and require a ton of code to run everything properly. I worry that if development is artificially sped up, that code problems that would have been caught in the testing get caught in production.
Of course the above kind of assumes a decent dev team and a good code base. What I said could be moot if what's really happening is the technical debt of some of this code is so massive that simple changes take months to make and ensure correct, which would be a problem for sure.
Either way, blaming the language probably isn't the right way to go about this.
http://www.defenseindustrydaily.com/f22-squadron-shot-down-b...
He was trying to be funny to make a point... but there is definitely a nugget of truth to it. Time is hard. (I write embedded DVR software these days)
But seriously, Ada is well designed and not difficult. Ada is not part of the problem, this would take longer and be less reliable in C++.
I'll bet it is. A car is significantly simpler than a fighter plane (at all levels of resolution), even when you discount weapons and detection systems. Which you can't discount when you're building software for a plane.
Furthermore, the risks involved in a fly-by-wire avionics soft are much greater than in cars in case of bug or crash: there are no drive-by-wire production cars today, although there are many electronics systems.
And even if the F22 is 10x as complex, Ford still has 100,000 cars to spread the cost across.
So, safely automating cars is a harder problem, but not because the car itself is a more complex vehicle.
I agree totally with you then. Even accounting for avionics, control surfaces, target acquisition, and so on and so forth, automating cars is a much harder nut to crack, software-wise.
1. http://en.wikipedia.org/wiki/Electronic_throttle_control 2. http://en.wikipedia.org/wiki/Brake-by-wire
http://en.wikipedia.org/wiki/Power_steering#Electric_systems
Several years ago, a friend bought a BMW M6 the year they came out. A few days later, he noticed when the tires were pointed straight forward, the steering wheel was not centered. He took it to the shop, and they told them "that's a software bug".
Though I can't claim any professional experience, lots of my college education was straight from DoD/Navy expats who wrote military software.
There are lots of firms in the midwest that write this kind of software. John Deere, Lockheed, etc.
On projects like this I would worry more about accumulated technical debt from decades of modification than the language they're written in. (I suppose the language can complicate the task of hiring programmers who are skilled with its idiosyncrasies, but that's hardly an insurmountable or crippling problem.)
Our compiler package also came with an extensive concurrency API that offered a variety of threadsafe containers comparable (again) to java.concurrent - and this was software from the late 80s/early 90s!
What was bad about Ada was Ada 95. It strove to make Ada into an object-oriented language, but did a poor job of it with some very tortured syntax. edit what Masklinn said - "bolted on" is a perfect way to put it.
1. It's a very lawyery language, there are very few things the compiler will accept to infer, which makes Ada tedious to read and write.
2. The strange mix of underscores and uppercases that is the normal Ada writing style (I believe Ada identifiers are case-insensitive, code from the 80s tends to be VERY_UPPERCASE_HEAVY while the same code now Tends_To_Be_Strangely_Capitalized) makes my head hurt.
And since this is avionics, they're probably dealing with embedded code (which tends to be even less readable) as well...
And as totalc notes, the OO additions of Ada 95 (if you have access to them) feel very bolted on and unnatural.
The Ada class started in '94 if a timeframe helps
Well not really, but Ada is alive and well in the guise of PL/SQL. You can see it if you look closely, type "desc sys.diana" into any Oracle DB, DIANA is "descriptive intermediate annotated notation for Ada".
Most static typed languages - C, Java, Haskell, etc are memory representation centric in their primitive types. Ada is usage centric.
You see that two ways.
First, in most languages any item with underlying implementation X can represent any legal value of X, even if it makes no sense. If you want to represent a quantity whose maximum value is one million, putting it in anything shaped like a 32-bit int will let it contain the illegal value "one million and one". Contrast Ada which will let you cap its legal range.
Second, in most languages any item with underlying implementation X can contain anything else with the same implementation. Your typedef'd int can be put into anything else int-sized. Contrast Ada, which won't permit you to mix apples and oranges if they are defined as distinct types with int storage.
If you're writing real-time avionics software, your choices are really only Ada, C and C++. Most companies I know of, including Airbus, are using C. Typically, avionics software has to be qualified to DO-178B/ED-12B standards which specifies certain development, testing and proofing requirements. Software verification tools like Astrée are also governed by DO-178B/ED-12B, though they are subject to a lighter verification process.