brainfuck-web-app VS z3

> Javascripts can be different, there is no guarantee that some half supported engine will run that specific code.

Half supported? Where is your source? Java Nashhorn was passing all ECMAScript 5.1 tests in 2012 (https://twitter.com/asz/status/258995374847565825)

> Same as brainfuck: https://github.com/EvanHahn/brainfuck-web-app

Brainfuck? JavaScript is most popular programming language (https://www.stackscale.com/blog/most-popular-programming-lan...) You're comparing apples to oranges. By the way I mostly work in Java, but I do not look down on JavaScript, it's shows ignorance.

As others have already said, person who wrote the library may not be familiar with your favorite language, moreover certain things are easier to do in some languages. This is not the attitude that we should be showing when receiving free work from someone. If you don't want to port it to your favorite language when needed that's ok, I'm just glad that it exists.

Has been done

See https://cacm.acm.org/magazines/2023/6/273222-the-silent-revo... and also modern production rules engines like https://drools.org/

Oddly, back when “expert system shells” were cool people thought 10,000 rules were difficult to handle, now 1,000,000 might not be a problem at all. Back then the RETE algorithm was still under development and people were using linear search and not hash tables to do their lookups.

Also https://github.com/Z3Prover/z3

Note “the semantic web” is both an advance and a retreat in that OWL is a subset of first order logic which is really decidable and sorta kinda fast. It can do a lot but people aren’t really happy with what it can do.

Code correctness is a lost art. I requirement to think in abstractions is what scares a lot of devs to avoid it. The higher abstraction language (formal specs) focus on a dedicated language to describe code, whereas lower abstractions (code contracts) basically replace validation logic with a better model.

C# once had Code Contracts[1]; a simple yet powerful way to make formal specifications. The contracts was checked at compile time using the Z3 SMT solver[2]. It was unfortunately deprecated after a few years[3] and once removed from the .NET Runtime it was declared dead.

The closest thing C# now have is probably Dafny[4] while the C# dev guys still try to figure out how to implement it directly in the language[5].

[1] https://www.microsoft.com/en-us/research/project/code-contra...

[2] https://github.com/Z3Prover/z3

[3] https://github.com/microsoft/CodeContracts

[4] https://github.com/dafny-lang/dafny

[5] https://github.com/dotnet/csharplang/issues/105

I believe, Nim also has this functionality, although, it uses the [0]Z3Prover tool with a nim frontend [1]"DrNim" for proving.

[0]https://github.com/Z3Prover/z3

Don't get me wrong, there are times when Microsoft got it right the first time that was technically far superior to their competitors. Windows IOCP was theoretically capable of doing C10K as far back in 1994-95 when there wasn't any hardware support yet and UNIX world was bickering over how to do asynchronous I/O. Years later POSIX came up with select which was a shoddy little shit in comparison. Linux caved in finally only as recently as 2019 and implemented io_uring. Microsoft research has contributed some very interesting things to computer science like Z3 SAT solver and in collaboration with INRIA made languages like F* and Low* for formal specification and verification. But all this dwarfs in comparison to all the harm they did.

Z3 theorem prover SMT solver might help you.

Other than that, you should look at Z3 which is pretty damn good at these sort of theorems/constraints.

In the end I used Z3 Julia bindings instead. The hardest part was to get the result back from it, because I kept running into assertion violations from inside Z3

I'm trying to learn a little bit about Predicate Transformer Semantics (PTS) as part of a quick exploration of Z3.

> And you propose me instead to go and reverse engineer library Js code which I am not that proficient in, and rewrite all code in Java instead?..

Yes, rather than demand others cater to your whims, frankly.

Do you realise how hypocritical it sounds to complain that you are not proficient in Javascript, when others might not be proficient in ?

Go use Z3 if you need a prover in C++ (or Java), its far more robust (provided its the type you're after) than someones 700 LoC JavaScript implementation.

https://github.com/Z3Prover/z3