[kstenerud]

I'm surprised that Apple didn't opt for a hybrid approach.

They control the OS. They also control Swift. So why not embed the Swift version that the app was built against, and then download that swift version to the user's device when they download an app that uses it. Then:

- The app runs against the exact Swift version it was built against

- The app size is smaller because you're no longer shipping the Swift libraries with the app

- The impact on the user's device space is minimized since it only downloads each version of Swift once (to be shared by all apps that use that version), and only on demand.

- If a new version of Swift comes out before an OS upgrade, simply add it to the list. It gets downloaded the same as the rest.

They could even add some predictive Swift downloading for the most popular versions of Swift to avoid unnecessary delays downloading it.

[e28eta]

I think you’re forgetting about apple’s frameworks, and the fact that _they_ want to use Swift. Their code runs inside your address space, and I think you’ll need a more complicated scheme to solve those problems.

[mort96]

I guess the problem then is that you end up with one copy of Swift installed per Swift version that's ever released more or less, which doesn't seem ideal from a space perspective.

[worewood]

That's what MS does with .net and DirectX for example.

Apple only needs to do this because they are charging a pornographic premium for storage.

[dangus]

MS does this because they aren’t in the same business as Apple.

Apple is in the device business. They make most of their revenue by selling you a new device.

A 10 year old Mac is basically a brick unless you want to mess with OpenCore Legacy.

The solution to this problem is to target a newer OS like Apple wants you to. Their users are going to buy a new system anyway, they’re the most affluent segment of the PC market.

[smoldesu]

> Their users are going to buy a new system anyway, they’re the most affluent segment of the PC market.

I thought Apple users were more likely to buy/own used devices than PC users were? I'm not fully caught-up on the statistics, but I'd assume that's still true.

[pjmlp]

Meanwhile PC users, plug a new disk into their desktop, or replace the hard disk on their laptop (plenty of options still available where disk, memory and battery can be exchanged).

[pmcp]

Still doing weekly live dj sets with my macbook from 2013, editing in Logic, researching music online, listening to Spotify,… Except for the battery, there is nothing wrong with this device of more than 10 years old.

[dangus]

So you’ve already lost feature and most security updates, 3 major releases behind.

I’ve got a 2012 Mac mini and it’s limping along with the OpenCore Legacy patcher. I got the kernel panics to stop but they came back with a recent update. I’m gonna sell the thing and probably switch those duties to a Linux server.

[eviks]

Wouldn't you be able to only store the diff of every version to some base version instead?

[mort96]

That should in theory be possible, yeah, though I can't imagine a great way of doing it. Do you want to add a bunch of complexity to the system's dynamic linker to make it understand "base + binary patch" dynamic libraries?

In any case, maybe you can add heaps of complexity to core OS things and save some disk space; but you still need the full patched dynamic library in memory when the process is running, so at the very least you'll end up with bloat from lots of versions of the dynamic libraries loaded in memory when processes with different versions are running...

Maybe you could tackle both of the problems by storing a base version of the dylibs and then have other dylibs which provide replacements for only the symbols which have changed between versions... but this would severely limit the kind of thing you can do without just basically having to override all symbols. And automating this process would be hard, since compiler upgrades could cause small code gen changes to a bunch of symbols whose behavior haven't changed and you wouldn't want to ship overrides for those.

In the end, while I'm sure there are things you could do to make this work (Apple has some talented engineers), I also understand why they wouldn't.