3 ms·

> Can’t you just break them? They’re violating the spec! > No, you can’t break them. You can. A vendor playing nice may provide advance warnings, fallbacks, a

> Can’t you just break them? They’re violating the spec! > No, you can’t break them. You can. A vendor playing nice may provide advance warnings, fallbacks, assess blast radius etc, but that's no way a given, some vendors will not act nicely and leave you out cold if you ignore the spec. Java 7 switched array.sort() to TimSort. It broke some users, they switched nevertheless and offered an override option for some time so people could migrate. Java 9 introduced the modules, which broke some things that tried to access internals, there were overrides for some time so people could migrate. By default Rust does not specify the field order of its structs, people relied on it anyway. Several releases changed the ordering algorithm, no opt-out was offered since there already was an annotation to specify a fixed layout, people just had to use it. It's called "API contract" for a reason, it puts obligations on both sides.

jerf 2y ago
I am reminded of how Postel's Law has fallen from Iron Law of the Internet to somewhat distasteful in the past 5-10 years. Yes, it's no fun to break your clients and customers today. But if you don't do it today, and you don't do it next month, next year, or the next four years, you'll find yourself in a position where you can't do anything anymore because you've basically let Hyrum's Law "build up" in your system until there's no room to move. Obviously, one should not willy-nilly break customers for no reason. The point is not to create a management metric around Number Of Times We've Broken The Customer and reward the team for getting their numbers up, up, up. The point is to retain flexibility and the ability to move forward, and that is done through intelligent design up front to the extent possible, and carefully selecting when to break customers over the course of years. It's always expensive and should definitely be treated as an expense, not a benefit on its own terms. But as the Hyrum's Law "builds up" its expense to the company over all will in not really all that long overwhelm the costs of the occasional breakage to stay up-to-date with the world.

jerf 2y ago

I am reminded of how Postel's Law has fallen from Iron Law of the Internet to somewhat distasteful in the past 5-10 years. Yes, it's no fun to break your clients and customers today. But if you don't do it today, and you don't do it next month, next year, or the next four years, you'll find yourself in a position where you can't do anything anymore because you've basically let Hyrum's Law "build up" in your system until there's no room to move. Obviously, one should not willy-nilly break customers for no reason. The point is not to create a management metric around Number Of Times We've Broken The Customer and reward the team for getting their numbers up, up, up. The point is to retain flexibility and the ability to move forward, and that is done through intelligent design up front to the extent possible, and carefully selecting when to break customers over the course of years. It's always expensive and should definitely be treated as an expense, not a benefit on its own terms. But as the Hyrum's Law "builds up" its expense to the company over all will in not really all that long overwhelm the costs of the occasional breakage to stay up-to-date with the world.