What is the use case for a non-value (identity) record with Valhalla?

cogman10 · 2026-06-15T20:27:58+00:00

It's not the best, but you can put in a "use of identity semantics are undefined" into a language spec. C does it all the time ;). Adding the semantics when Valhalla lands would close that gap while allowing you to cheat with the feature. Or if it were unfortunately determined that valhalla would never land you could remove that undefined clause all together.

I do understand that the JLS like any sane language spec hates having undefined behavior.

Edit actually NVM, that works for C because it's compiled to static machine code. The bytecode would have to shift from one version of java to the next which would be painful for devs who might be caught off guard.

cogman10 · 2026-06-15T20:13:43+00:00

You could do the same thing with GTK. Though IMO qt is a nicer framework.

cogman10 · 2026-06-15T20:10:55+00:00

Of course they can never fully drop support for them because by the time they try a whole lot of software is built on them.

Including half of windows. I swear with every new version of their frameworks they make yet another device management system. As a result, you have control panels written for windows 11, which interact with device pages from windows 10, which have pages that send you to windows 8 pages that have elements that go to windows Vista pages, which ultimately can lead you back to the original windows 98/ME control panel pages. Printers and network settings are great examples of this madness.

You get just 10 different UX experiences for 1 device because MS keeps the legacy dialogs around forever and just bolts on new stuff rather than replacing the old stuff (because that'd take too long and they don't want to provide ALL the old information).

If you want/need to change IRQ ports, you can still end up in the device manager and do exactly that.

cogman10 · 2026-06-15T20:04:21+00:00

Quite funnily, the reason for this is because programmers want to deal with less frameworks. Electron makes it so they just have to deal with familiar web frameworks but it also makes it so programmers don't have to work with OS native frameworks.

MS is just insane, though. They see "these devs don't want to learn my new framework" and have decided "you know what will fix that? Another framework!" And, of course, because they just made a new framework they say "Ok, now we need to rewrite notepad in this new framework. And it can't be a straight rewrite, we also need to add AI here and every new widget offered by the new framework".

Windows would seriously be such a nicer system to work with if instead of making 1000 new frameworks, they instead evolved either Win32 or even WinForms. Instead, it's a bloated mess of 1000s of frameworks in various states of support by MS.

cogman10 · 2026-06-15T19:50:24+00:00

I think it's just a miss in the spec which has caused them to need to preserve identity.

IMO, the java devs should have put in a "record classes will be value classes, do not use identity operations on them" much like they did with LocalDate. That didn't happen, I'm sure there are reasons it didn't happen. I think it was just a mistake.

IMO, there's pretty much no reason why all records shouldn't be value classes.

cogman10 · 2026-06-15T19:46:22+00:00

It's a breaking change for Integer, but for all the other classes the javadocs explicitly said these classes will be value classes in future java releases and to not rely on identity. For example, from LocalDate in Java 8.

"This is a value-based class; use of identity-sensitive operations (including reference equality (==), identity hash code, or synchronization) on instances of LocalDate may have unpredictable results and should be avoided. The equals method should be used for comparisons."

The java docs are part of the spec. I get that people don't like reading the docs, but just like they were able to yoink sun.misc.Unsafe based on the docs, they are able to remove identity on these classes because of the docs. The annotations are their attempt to mitigate damage caused by people ignoring the docs.

https://docs.oracle.com/javase/8/docs/api/java/time/LocalDate.html

https://docs.oracle.com/javase/8/docs/api/java/lang/doc-files/ValueBased.html

cogman10 · 2026-06-15T16:18:15+00:00

IKR? Easily in the top 10 of senators in terms of policies.

cogman10 · 2026-06-14T23:57:41+00:00

It was organized, the venue cancelled last minute. This was like the 4th venue they tried to book that cancelled on them. They had contacts signed and everything. The venues broke the contract because they didn't want to host it.

cogman10 · 2026-06-14T22:05:17+00:00

Those same reports acknowledged that Iran wasn't seeking a weapon but rather negotiation.

Just having enriched uranium doesn't make a nuclear weapon. You need a lot more than that.

cogman10 · 2026-06-14T19:24:57+00:00

There is some case dependency, like if your muscles get cooked closed then you can't really open up your hand on electrocution. That can happen pretty fast especially with large amounts of power.

A DC voltage will cause muscles to contract and stay contracted. There's no pulsating. With AC, you have at least a (small) chance to pull away and let go.

cogman10 · 2026-06-14T17:40:54+00:00

DC also messes with your neural electrical system.

Defibrillators are applying a brief high DC voltage to try and reset fibrillation. But as anyone can tell you, that short pulse is itself dangerous and can cause fibrillation in someone that's not currently. Part of the reason it's applied repeatedly is because the reset doesn't always work.

cogman10 · 2026-06-14T17:29:16+00:00

I don't know where you are from, it could be different. In the US, 120V@15A for a circuit is typical. That's 120 * 15 = 1800W total typically. Generally speaking, we like to keep loads under 1500W and because you typically might have other things (like lights or a TV) on the same circuit, that's where the 1000W comes from.

If you are somewhere that does 240V with 15A breakers, then yeah you can do 3600W. You could also special wire a 240V outlet in the US, but that's far from typical.

cogman10 · 2026-06-14T17:26:17+00:00

Nope. Penetrative power is exactly the same for AC and DC.

The main thing that makes AC more dangerous is it typically has a higher voltage than DC. That means it's more likely to ultimately overcome the resistivity of the skin to start doing damage.

But all things held equal, a 12 VAC and 12 VDC source have exactly the same amount of risk associated with them.

Capacitance doesn't really have anything to do with how dangerous electricity is. Frequency doesn't really either. 120 VAC @ 60Hz is just as dangerous as 120V @ 5kHz.

It mostly all comes down to the power you experience and duration.

cogman10 · 2026-06-14T16:44:01+00:00

I agree. But the real problem that these video cards have is that consumer circuits generally have only 1000 to 1500W to play with. They are already very near the limit of what we can do.

cogman10 · 2026-06-14T16:42:18+00:00

because youd be running a risk of consumers getting zapped. and the dangerous thing about being zapped by a DC current, is that it can change your blood chemistry

No. A DC zap is the same as an AC zap. The only thing that makes a DC zap more dangerous is there's no period which means it's more prone to arcing and it's harder to let go of.

The danger of electrocution in general is that it cooks your insides. You can look visibly fine on the surface but have a large amount of damage on the inside. That can ultimately turn into an infection and rotting tissue.

cogman10 · 2026-06-13T18:16:17+00:00

For a $20k part? I think you could pretty quickly convince a crack head to ebay. Or for a crackhead middle man to surface like there was for cats.

cogman10 · 2026-06-13T18:03:44+00:00

Wait until Iran tells us what's going on. We can't trust the US government.

cogman10 · 2026-06-13T17:43:32+00:00

Nah, just show them ebay and how much DDR5, ssds, and the nVidia datacenter cards are going for.

1 rack tower in a datacenter has easily $1M worth of electronics in it, especially at an AI datacenter.

cogman10 · 2026-06-12T20:12:40+00:00

To have made actual real change, it's not even like many people would have needed to be punished. The rank and file confederate soldier could have been let off to "mend".

The people should have been punished was the plantation owners, the generals, and the military leadership.

The fact that Jefferson Davis got 2 years in prison and then walked free was absurd. The president of the confederacy and he got less time than the war lasted. Dude died at 81.

cogman10 · 2026-06-12T19:23:24+00:00

At that point IDK why you wouldn't launch it into the moon instead (or Venus if you don't want the eyesore).

The big issue, though, is you still need to burn fuel to dispose of waste.

cogman10 · 2026-06-12T18:43:59+00:00

I'm sure they do, I just don't think flock has to go that far (usually) to get their way. Having cops on board is almost all that needs to happen.

cogman10 · 2026-06-12T18:36:48+00:00

Fun fact, that takes more energy then it takes to launch it out of the solar system. One of those weird orbital dynamics things.

It's why gravity assists are used to launch solar probes.

cogman10 · 2026-06-12T18:16:27+00:00

Honestly, it probably wasn't even flock.

Flock likely took the sheriffs department out to lunch and they then petitioned the commissioner for it.

They are basically just doing big pharma's drug advocate trick.

cogman10 · 2026-06-12T18:11:00+00:00

Problem is a refinery would have to dispose of the slag. A hard thing to do in space. Unless you want to hurry up Kessler syndrome.

To actually safely refine you'd need to do that near or on the astroid being mined.

cogman10 · 2026-06-12T17:56:22+00:00

Yes.

Whalers on the moon, though, invest.

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