Airbus Chooses GNAT Pro Ada for Development of Unmanned Aerial System • Hacker News Board

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

#201

Post by micronian2 » Sun, Sep 20, 2020, 7:42 AM UTC

etaioinshrdlu wrote: post #27

Does anyone use Ada for general purpose programming, like for where one might otherwise use Python, Go, nodejs, or something like that? Is it used for any low-reliability areas?

I don't know Python, Go, or nodejs, but with regard to general purpose programming, you can look at some of the free tools and libraries on AdaIC (https://www.adaic.org/ada-resources/tools-libraries/). There is a man named Gautier, who actively develops a variety of tools (e.g. 3D gfx, Excel file producer, games, code editors, etc). Check out his blog page: https://gautiersblog.blogspot.com/search/label/Ada

In addition, I know for a fact that Rapita Systems (https://www.rapitasystems.com/) uses Ada a lot in their products.

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

#202

Post by OneWingedShark » Mon, Sep 21, 2020, 4:20 PM UTC

andi999 wrote: post #137

kqr wrote: post #74

Earlier quoted context omitted.

Key word in that sentence: had. I picked up Ada essentially because it seemed to me a more actively maintained Pascal. (I've since learned that Free Pascal/Lazarus might not be as dead as it first appeared.)

How are compile times in ada? (Best thing about pascal/delphi)

They are typically pretty good; the design helps the compiler to not have to re-compile everything any time something is changed, so most of your variance is going to boil down to "how much did you change."

That said, Delphi is blazing fast so Ada will seem a bit slower, typically… but [IME] it's generally not going to be something as slow as a lot of C++ programs.

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

#203

Post by OneWingedShark » Mon, Sep 21, 2020, 5:58 PM UTC

c-cube wrote: post #115

tasogare wrote: post #104

Earlier quoted context omitted.

Rust is akin to the JS framework du jour in respect to safe languages: overpaid bored engineers started a project without bothering checking existing work or dismissing what they found, then they market the resulting (still unfinished) language as something radically new and solving most programming language issues. Some people followed because of the novelty effect and the company that spanned it, which allowed for…

That is just incorrect. Ada seems pretty nice, but it does not have a borrow checker, does it? I think deallocation is considered unsafe? Documentation points to [Unchecked_Deallocation]( https://docs.adacore.com/live/wave/arm12/html/arm12/arm12-13... ) . Rust has automatic (as in, you don't even need to call `free()`), safe deallocation of resources. Of course, the syntax, ergonomics, and the modern looking website…

> Ada seems pretty nice, but it does not have a borrow checker, does it? IIUC, there is a SPARK implementation that does: https://blog.adacore.com/using-pointers-in-spark / https://www.adacore.com/uploads/techPapers/Safe-Dynamic-Memo...

That said, there are whole classes of problems where, thanks to Ada's design, you don't even NEED pointers where you would in C or similar languages: http://video.fosdem.org/2016/aw1124/memory-management-with-a...

> I think deallocation is considered unsafe? This too depends; Ada was designed so that a garbage-collector could be used, even in Ada83, most implementations do not take advantage of this. (There are JVM and DOTNET implementations where GC is required though.)

To achieve safe deallocation it is often delegated to scopes so that exiting a scope clears out all the memory you were using; see stack-allocation, pools/subpools, and local-declarations/inline-declarations.