Java/C# vs Rust [LWN.net]

Java/C# vs Rust

Posted Aug 18, 2024 12:58 UTC (Sun) by pizza (subscriber, #46)
In reply to: Java/C# vs Rust by khim
Parent article: Standards for use of unsafe Rust in the kernel

> Sure, Java have shown that you may develop things in a managed code, but List machines did that before Java. Java have shown that you may write portable code but AS/400 did that before.
>None of achievements that Java may show are new and the ones that are new are completely unrelated to these things that Java was supposed to achieve.

Congratulations, you just demonstrated my point.

Lisp machines and AS/400s were about as far removed from commodity systems as it could get, and were effectively unobtanium for mere mortals.

...Unlike Java, which you could obtain for low-to-zero cost and could run on the systems you already had.

Like it or not, Java's particular combination of features and accessibility changed the entire trajectory of the industry.

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Java/C# vs Rust

Posted Aug 18, 2024 13:35 UTC (Sun) by khim (subscriber, #9252) [Link] (5 responses)

> Lisp machines and AS/400s were about as far removed from commodity systems as it could get, and were effectively unobtanium for mere mortals.

And how is that a bad thing? They were solving programs that either are not needed by mere mortals or are not solved by Java.

Java managed to [ab]use managed code but failed to achieve thing that managed code is really good for: forward compatibility. While AS/400 doesn't even give you an ability to execute in native code it's not uncommon for a Java program to code with it's own version of JRE because it may misbehave with any other version and conversion between .NET 1.x, 2.x and .NET core is pretty damn non-trivial.

Thus, in the end, C# and Java achieved intermediate goals these exotic systems achieved in pursit of worthwhile goals yet failed to achieve anything worthwhile outside of hype train.

> Like it or not, Java's particular combination of features and accessibility changed the entire trajectory of the industry.

Isn't that my original point? Java have diverged the industry, made it waste trillions of dollars on mirage that never materialized, sent it into a dead end, and now we would need to spend more trillions of dollars to undo all that damage.

Hardly something to celebrate.

Java/C# vs Rust

Posted Aug 18, 2024 13:58 UTC (Sun) by pizza (subscriber, #46) [Link] (4 responses)

> Java have diverged the industry, made it waste trillions of dollars on mirage that never materialized

...So billions of lines of inherently memory-safe code deployed onto commodity systems never happened?

Java/C# vs Rust

Posted Aug 18, 2024 14:55 UTC (Sun) by khim (subscriber, #9252) [Link] (3 responses)

> ...So billions of lines of inherently memory-safe code deployed onto commodity systems never happened?

Of course they happened! Billions of lines of code already written is various memory-safe language (from COBOL and Clarion to Visual Basic and FoxPro) were, with great pains, rewritten in two other, more resource hungry memory safe languages.

Yes, these languages never have been using “managed code” or “tracing garbage collection”, but they were perfectly memory safe and they worked perfectly fine.

No matter how you look on it the whole thing it looks like a net negative to me: we haven't gotten any tangible benefits from that rewrite (although some industries have gotten rich, that's true, but that's like burning the house to heat a stew), code that was before than “grand revolution” written in memory safe languages was still written in memory safe languages (only now with lots of more unneeded complexity) and code written in non-memory safe languages continued to use non-memory safe languages.

Java/C# vs Rust

Posted Aug 19, 2024 12:48 UTC (Mon) by pizza (subscriber, #46) [Link] (2 responses)

> No matter how you look on it the whole thing it looks like a net negative to me: we haven't gotten any tangible benefits from that rewrite

Wait, _rewrite_? Surely you jest.

New stuff only rarely replaces the old stuff; instead it's layered on top. It's turtles all the way down.

And again, it is a simple FACT that Java is vastly more approachable than the stuff it supplanted, and was useful for nearly everything, from deeply embedded stuff [1] to teaching/toy problems [2] to desktop applications [3] to enterprise consultant wet dreams -- All from the same base tooling. That was a *HUGE* change over the former status quo.

Sure, many of its use cases have since been better served with newer stuff. So what? Isn't that the fate of all technology?

[1] Multiple generations of ARM processors ran the Java bytecode natively
[2] Completely supplanting Pascal in introductory programming courses
[3] Including browser applets. Which I don't miss.

Java/C# vs Rust

Posted Aug 19, 2024 13:39 UTC (Mon) by khim (subscriber, #9252) [Link] (1 responses)

> New stuff only rarely replaces the old stuff; instead it's layered on top. It's turtles all the way down.

> And again, it is a simple FACT that Java is vastly more approachable than the stuff it supplanted

Can you stop contradicting yourself at least in two adjacent sentences?

> Multiple generations of ARM processors ran the Java bytecode natively

Nope. Few ARMv5 CPUs has the ability to run some small subset of Java bytecode. It was, basically, to run few games on some phones and for nothing else. Starting from ARMv6 only “null” implementation of Jazelle is supported.

So that's another example of pointless waste (thankfully very limited compared to the damage caused by the large C#/Java crazyness).

> Completely supplanting Pascal in introductory programming courses

Yeah. And also Scheme in some course. Another negative.

> That was a *HUGE* change over the former status quo.

Where do you see me objecting? Sure, C#/Java caused lots of changes. Almost all of them negative.

But you are arguing as if I'm objecting about magnitude of change… I'm not! C#/Java caused absolutely huge negative change.

There were, also, some minuscule positive changes, sure, but compared to problems that C#/Java craze caused they are hard to even notice.

> Sure, many of its use cases have since been better served with newer stuff.

That's not important. What is important is that almost all use cases are better served by older stuff.

> Isn't that the fate of all technology?

Sure. But C#/Java is different: that's the rare case where bad technology was replaced with worse one.

Wanted to say that it's the only such change, but nope, there are many other like that: solar and win power plants, electric cars, etc. That have only started happening recently. About quarter century ago. But, sadly, it's not limited to IT and not limited to C#/Java. True.

But the fact that was achieved by temporary disconnect between feasibility of technology and availability of funding doesn't make that change good and we would pay for that stupidity, and, it looks like, rather sooner than later.

Microsoft and Sun have already paid the price, but I doubt it would be limited to that.

Maybe this is enough?

Posted Aug 19, 2024 14:17 UTC (Mon) by corbet (editor, #1) [Link]

So this has gone on for quite some time; I don't think any minds will be changed at this point. Maybe time to wind it down?

Thank you.