4 ms·

> just want you to either do what I asked you to do or fail gracefully And most of the time, this is EXACTLY what happens. In fact most libraries that do use

> just want you to either do what I asked you to do or fail gracefully And most of the time, this is EXACTLY what happens. In fact most libraries that do use panics, recover them internally and return errors to the callers. Again: panics are not errors, panics are not exceptions. A library should never panic in a way that it's caller notices, UNLESS it met a condition that simply is not recoverable, not by the library itself, and not by it's caller. Yes, this requires care by the libraries authors not to overuse panics. Yes, there are libraries that do overuse them. No, this doesn't change anything about what I wrote. If a library I use would do that, I would either fix the library, or find a better one. > Uh, no. If a piece of the road is missing Okay, let me try again with a better analogy: If a cars engine breaks down, the car will stop. It doesn't matter if the driver wants the car to go for another 100 kilometers. It stops. Period. Not because anyone or anything "wants" the car to stop, but because its engine "package" met a condition, under which the further running of whatever context it is used in (in this case, the car), is no longer feasible and/or possible. That is exactly what panicking in a way that hits the runtime communicates: Oh noes, the engine just broke down, and now the machine can no longer run.

zoky 3y ago
I’m not sure how valuable these analogies actually are, but your example of the broken engine really seems to go towards my point. If the car breaks down, the driver still has several options: coast downhill, switch to a different car, pull a bicycle out of the trunk, or just get out and continue on foot. But the car enforcing the end of the trip by simply exploding and killing the driver isn’t really an acceptable response to engine failure. A library that unrecoverably crashes your program for any reason is defective by design, and a programming language that purposely allows a library to do so as a design choice is also defective by design in my opinion.
- usrbinbash 3y ago
  > If the car breaks down, the driver still has several options: The one option he doesn't have though: Continue running the car as-is. And that's the point I am making. > and a programming language that purposely allows a library to do so as a design choice is also defective by design in my opinion. You are entitled to your opinion of course, but I'm not going to agree, and it seems a lot of people are completely fine with that design decision: https://madnight.github.io/githut/#/pull_requests/2023/3 https://madnight.github.io/githut/#/pull_requests/2023/3 Again, the library isn't "crashing the program". The library meets a condition under which it can no longer function, no matter what the caller does, and can no longer function in a way that makes running the entire program infeasible. That is the point of panicking and not recovering it within the library. And yes that is the libraries call to make. Yes, it needs to have a very good reason to make that call. Very few libraries panic in that way. And the ones that do, and are widely used, have very good reasons to. If libraries do so without a good reason, then people stop using them.
  - zoky 3y ago
    > The one option he doesn't have though: Continue running the car as-is. And that's the point I am making. Exactly! So raise an EngineFailure exception and let the driver decide how to proceed. But don’t kill the driver because you can’t figure out how anyone could possibly recover from what seems to you like the end of the world, when it might just be a speed bump as far as the driver is concerned. > You are entitled to your opinion of course, but I'm not going to agree, and it seems a lot of people are completely fine with that design decision: https://madnight.github.io/githut/#/pull_requests/2023/3 https://madnight.github.io/githut/#/pull_requests/2023/3 I mean, a lot of people are fine with programming in PHP, that doesn’t make it a good choice. > And yes that is the libraries call to make. No. Absolutely, 100%, beyond question not. The library can’t possibly know every conceivable circumstance in which it is called, and therefore it is a guarantee that there is some conceivable set of circumstances from which what appears to be a fatal error from the library’s perspective is nothing more than a blip, or even a complete non-issue, from the perspective of the caller. Panicking the calling program so it can’t possibly continue is an abuse of trust, and any library that does so shouldn’t be admitted to any repo, and any language that allows it to do so is broken by design and should be considered harmful.
    - usrbinbash 3y ago
      > Exactly! So raise an EngineFailure exception and let the driver decide how to proceed. In the analogy, the car is the program. The ENTIRE program. It is the limit of the analogy. The car driving is the program running. The car no longer being able to drive, is the program not running. Everything outside of that is out of the scope of the analogy. > I mean, a lot of people are fine with programming in PHP, that doesn’t make it a good choice. That is absolutely true, but it doesn't make PHP "defective". If someone is unhappy with how Go's `panic` works, they can use something else, same as I am not going to use PHP. > No. Absolutely, 100%, beyond question not. Yes, absolutely, 100%, beyond question it is. The library is an implementation hidden behind a public interface. Same as I don't have to worry about how it performs it's functions, I don't have to worry how it determines what it considers to be an irrecoverable failure condition. If I disagree with a libraries decision on that, I have the same options I have if I disagree with how it's interface works (assuming it is open source): 1) I can fork it and roll my own implementation. 2) I can vendor-copy it and adapt it locally for the scope of that project. 3) I can use another lib (including writing my own from scratch). > The library can’t possibly know every conceivable circumstance in which it is called It doesn't have to. If the engine breaks down, it does't matter if the car is yellow, the sun is up, or the driver was born on a Tuesday. The engine is broken, and cannot run. End of story. If there are conceivable circumstances under which the lib should continue running instead of panicking, it is the libs job to implement it, same as it is its decison what these circumstances are, and when they apply. > and any language that allows it to do so is broken by design and should be considered harmful. Well, I think we are gonna have to agree to disagree on this. Considering Go's success and continuous growth, it is pretty safe to say that many people and industries don't consider it broken, nor harmful.

zoky 3y ago

I’m not sure how valuable these analogies actually are, but your example of the broken engine really seems to go towards my point. If the car breaks down, the driver still has several options: coast downhill, switch to a different car, pull a bicycle out of the trunk, or just get out and continue on foot. But the car enforcing the end of the trip by simply exploding and killing the driver isn’t really an acceptable response to engine failure. A library that unrecoverably crashes your program for any reason is defective by design, and a programming language that purposely allows a library to do so as a design choice is also defective by design in my opinion.

usrbinbash 3y ago
> If the car breaks down, the driver still has several options: The one option he doesn't have though: Continue running the car as-is. And that's the point I am making. > and a programming language that purposely allows a library to do so as a design choice is also defective by design in my opinion. You are entitled to your opinion of course, but I'm not going to agree, and it seems a lot of people are completely fine with that design decision: https://madnight.github.io/githut/#/pull_requests/2023/3 https://madnight.github.io/githut/#/pull_requests/2023/3 Again, the library isn't "crashing the program". The library meets a condition under which it can no longer function, no matter what the caller does, and can no longer function in a way that makes running the entire program infeasible. That is the point of panicking and not recovering it within the library. And yes that is the libraries call to make. Yes, it needs to have a very good reason to make that call. Very few libraries panic in that way. And the ones that do, and are widely used, have very good reasons to. If libraries do so without a good reason, then people stop using them.
- zoky 3y ago
  > The one option he doesn't have though: Continue running the car as-is. And that's the point I am making. Exactly! So raise an EngineFailure exception and let the driver decide how to proceed. But don’t kill the driver because you can’t figure out how anyone could possibly recover from what seems to you like the end of the world, when it might just be a speed bump as far as the driver is concerned. > You are entitled to your opinion of course, but I'm not going to agree, and it seems a lot of people are completely fine with that design decision: https://madnight.github.io/githut/#/pull_requests/2023/3 https://madnight.github.io/githut/#/pull_requests/2023/3 I mean, a lot of people are fine with programming in PHP, that doesn’t make it a good choice. > And yes that is the libraries call to make. No. Absolutely, 100%, beyond question not. The library can’t possibly know every conceivable circumstance in which it is called, and therefore it is a guarantee that there is some conceivable set of circumstances from which what appears to be a fatal error from the library’s perspective is nothing more than a blip, or even a complete non-issue, from the perspective of the caller. Panicking the calling program so it can’t possibly continue is an abuse of trust, and any library that does so shouldn’t be admitted to any repo, and any language that allows it to do so is broken by design and should be considered harmful.
  - usrbinbash 3y ago
    > Exactly! So raise an EngineFailure exception and let the driver decide how to proceed. In the analogy, the car is the program. The ENTIRE program. It is the limit of the analogy. The car driving is the program running. The car no longer being able to drive, is the program not running. Everything outside of that is out of the scope of the analogy. > I mean, a lot of people are fine with programming in PHP, that doesn’t make it a good choice. That is absolutely true, but it doesn't make PHP "defective". If someone is unhappy with how Go's `panic` works, they can use something else, same as I am not going to use PHP. > No. Absolutely, 100%, beyond question not. Yes, absolutely, 100%, beyond question it is. The library is an implementation hidden behind a public interface. Same as I don't have to worry about how it performs it's functions, I don't have to worry how it determines what it considers to be an irrecoverable failure condition. If I disagree with a libraries decision on that, I have the same options I have if I disagree with how it's interface works (assuming it is open source): 1) I can fork it and roll my own implementation. 2) I can vendor-copy it and adapt it locally for the scope of that project. 3) I can use another lib (including writing my own from scratch). > The library can’t possibly know every conceivable circumstance in which it is called It doesn't have to. If the engine breaks down, it does't matter if the car is yellow, the sun is up, or the driver was born on a Tuesday. The engine is broken, and cannot run. End of story. If there are conceivable circumstances under which the lib should continue running instead of panicking, it is the libs job to implement it, same as it is its decison what these circumstances are, and when they apply. > and any language that allows it to do so is broken by design and should be considered harmful. Well, I think we are gonna have to agree to disagree on this. Considering Go's success and continuous growth, it is pretty safe to say that many people and industries don't consider it broken, nor harmful.