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Java 21 makes me like Java again

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Re: Java 21 makes me like Java again

#411

Post by peterashford »

quelltext wrote: post #326
iopq wrote: post #321

Earlier quoted context omitted.

Checked exceptions are gross, they get in the way when you're prototyping, and you end up just ignoring them anyway (since you're prototyping)

The ergonomics of checked exceptions may be debatable but compared to golangs explicit error handling at essentially each function call is definitely worse.

Yeah, I've got a lot of Java experience and a wee bit of Go language experience and I agree with you. I like Go in almost every way except for it's error handling. It's just wrong to have to check every goddam function one by one

Re: Java 21 makes me like Java again

#412

Post by mrkeen »

slotrans wrote: post #231

> This set of changes allows Java to express one of the foundations of functional programming that the language never could before - Algebraic data types, along with idiomatic ways of using them. And here I thought the foundation of functional programming was functions , which Java still doesn't have. Seriously, functional programming is about functions, not types.

> And here I thought the foundation of functional programming was functions, which Java still doesn't have.

> Seriously, functional programming is about functions, not types.

Well it does have methods and it does have "Functions" (not to mention "Bifunctions", whatever those are). And there's certainly nonsense around exceptions and referring to outer variables. And no currying.

But if I understand you correctly, you real complaint is about not having effect-free functions, right? But then it becomes about the type system again, because that would be the mechanism to prevent effects.

Re: Java 21 makes me like Java again

#413

Post by speedgoose »

classabove wrote: post #316
speedgoose wrote: post #264

Earlier quoted context omitted.

My main pet peeve with Golang is to use single letter or very short abbreviations when naming variables. The Golang documentation recommends what is considered a bad practice by most programmers communities.

Are you specifically referring to method function receiver type annotations? Those are often left shorthand but shouldn't exist out of the type definition file anyway eh?

I’m referring to this guideline:

> Variable names in Go should be short rather than long. This is especially true for local variables with limited scope. Prefer c to lineCount. Prefer i to sliceIndex.

https://github.com/golang/go/wiki/CodeReviewComments#variabl...

Re: Java 21 makes me like Java again

#414

Post by lenkite »

osigurdson wrote: post #334
northern-lights wrote: post #31

The biggest feature in Java 21 is the release of Virtual Threads: https://openjdk.org/jeps/444 For some reason, this is missing from the article. If there was any feature that would sway existing Golang developers to switch to Java, it would be this. It would perhaps also convince the haters of the reactive-style concurrency patterns.

I once posted an Ask HN: what are your build times. A golang developer stated their 25 million line project compiles in less than half a second. If that is really the case, I must say, this is very impressive and potentially a reason to switch from other languages.

Isn't this an exaggeration ? I have a 100k line go project and it takes several seconds to compile. No idea how a 25m line project compiles in less than half a second.

Re: Java 21 makes me like Java again

#415

Post by tommiegannert »

jjav wrote: post #366
northern-lights wrote: post #31

The biggest feature in Java 21 is the release of Virtual Threads: https://openjdk.org/jeps/444 For some reason, this is missing from the article. If there was any feature that would sway existing Golang developers to switch to Java, it would be this. It would perhaps also convince the haters of the reactive-style concurrency patterns.

> The biggest feature in Java 21 is the release of Virtual Threads Is there a good honest writeup on why is this interesting? Very curious. The earliest JVMs had this, green threads. Performance was terrible so it was eventually dropped. I want to fully utilize every CPU and every core I have, why do I want green/virtual threads again?

For me, it's the difference between code structure and resource usage.

Green threads are for a cleaner code structure. async/await comes quite close, but requires function coloring, creating high coupling. The threads have to have low overhead, so that I don't have to think about whether I should create a new one or not.

Kernel threads are for parallelism and scaling across cores.

Re: Java 21 makes me like Java again

#416

Post by peterashford »

osigurdson wrote: post #334
northern-lights wrote: post #31

The biggest feature in Java 21 is the release of Virtual Threads: https://openjdk.org/jeps/444 For some reason, this is missing from the article. If there was any feature that would sway existing Golang developers to switch to Java, it would be this. It would perhaps also convince the haters of the reactive-style concurrency patterns.

I once posted an Ask HN: what are your build times. A golang developer stated their 25 million line project compiles in less than half a second. If that is really the case, I must say, this is very impressive and potentially a reason to switch from other languages.

I work on a product written in Go which is considerably smaller than 25 million lines and our compile times are... really... really long. I really don't believe that claim at all. If it's true, I would love to see how it's done because that is SOOO far away from my daily experience.

Re: Java 21 makes me like Java again

#417

Post by neonsunset »

kaba0 wrote: post #385
neonsunset wrote: post #226

Earlier quoted context omitted.

Java is an inferior language to C#. To get a superior language you would likely have to go for Kotlin. There is no comparison, because Java gets features today that C# had for years. Not even mentioning having to retrofit green threads because adopting async/await (used by TS, Rust, Swift and other languages) is impossible at this point.

You can’t decide language superiority by the number of features. While C# indeed has many cool features, I do think it has already went into C++ territory where all the different, independently cool features have very non-trivial interactions that make it very hard to reason about. Also, async-await is not a good thing — virtual threads are superior in every way in case of a managed language.

Why async/await is not a good thing? What makes green threads better? Do you know the difference, the issues async/await addresses that green threads simply do not?

Re: Java 21 makes me like Java again

#418

Post by lenkite »

riku_iki wrote: post #194
kaba0 wrote: post #190

Earlier quoted context omitted.

> you have full control and bare-metal-native performance without compromises. Not even you believe that, right? Especially with regards to Go.. Go is closer to JS than to Rust/C++.

as soon as you copy your struct by value around, it is easy task for escape analysis to decide to put struct on stack. also, golang has arena API now, and it also makes heap allocations super cheap if you manage to integrate it into app life cycle.

Golang doesn't have copy elison unlike C++ so in principle you need to leverage the heap escape anyways.

Golang's arenas were an experiment that has already been ditched by the maintainer as un-feasible.

Re: Java 21 makes me like Java again

#419

Post by mrkeen »

kaba0 wrote: post #105
insanitybit wrote: post #16

The problems with Java can't be fixed by adding new things, you can't undo decades of ecosystem development, training, and ideology built on top of the idea that inheritance is really good idea and belongs everywhere. edit: I will say that as a Java developer I am grateful every day for the improvements to the language. Java is a very impressive language and I have a lot of respect for the people working on it.

Prefer composition over inheritance has been a common mantra for at least a decade, if not more. Maybe you should undergo the last decade of development and training. There will always be shitty devs, and since java is one of the biggest languages, it definitely has more than some ultra niche academic language no one uses. I don't think it is the fault of the language though, or if that somehow were a reason to choos…

> Prefer composition over inheritance has been a common mantra for at least a decade, if not more. Maybe you should undergo the last decade of development and training.

What are some other well known mantras? The null reference is a billion dollar mistake? Minimise mutability?

Maybe the language designers and library writers could catch up too.

Re: Java 21 makes me like Java again

#420

Post by trenchgun »

aranchelk wrote: post #110

> Why do we call them product types anyway? Answer in the piece is not wrong, but put more intuitively and succinctly: the total number of possible value (inhabitants) in a product type is the product of the quantity of inhabitants of the constituent types. Replace the “product”s with “sum”s and it works too. Interestingly, the total number of unique functions (judged only in terms of input and output) from a -> b ca…

>Answer in the piece is not wrong, but put more intuitively and succinctly: the total number of possible value (inhabitants) in a product type is the product of the quantity of inhabitants of the constituent types.

More intuitively and succintly: product type is equivalent to a cartesian product of sets

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