If unwrap() were named UNWRAP_OR_PANIC(), it would be used much less glibly. Even more, I wish there existed a super strict mode when all places that can panic are treated as compile-time errors, except those specifically wrapped in some may_panic_intentionally!() or similar.
React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED comes to mind. I did have to reach to this before, but it certainly works for keeping this out of example code and other things like reading other implementations without the danger being very apparent.
At some point it was renamed to __CLIENT_INTERNALS_DO_NOT_USE_OR_WARN_USERS_THEY_CANNOT_UPGRADE which is much less fun.
Not for this guy:
There is already a try/catch around that code, which produces the Result type, which you can presumptuously .unwrap() without checking if it contains an error.
Instead, one should use the question mark operator, that immediately returns the error from the current function if a Result is an error. This is exactly similar to rethrowing an exception, but only requires typing one character, the "?".
It's way less book-keeping with exceptions, since you, intentionally, don't have to write code for that exceptional behavior, except where it makes sense to. The return by value method, necessarily, implements the same behavior, where handling is bubbled up to the conceptually appropriate place, through returns, but with much more typing involved. Care is required for either, since not properly bubbling up an exception can happen in either case (no re-raise for exceptions, no return after handling for return).
That is the main reason why zig doesn’t have exceptions.
The great Raymond Chen wrote an excellent blog post on how this isn't really true, and how exceptions can lure programmers into mistakenly thinking they can just forget about failure cases.
Cleaner, more elegant, and harder to recognize https://devblogs.microsoft.com/oldnewthing/20050114-00/?p=36...
(ctrl-f for taskbar to skip to heart of his point.)
try {
data = some_sketchy_function();
} catch (e) {
handle the error;
}
vs result = some_sketchy_function();
if let Err(e) = result {
handle the error;
}
Or better yet, compare the problematic cases where the error isn't handled: data = some_sketchy_function();
vs data = some_sketchy_function().UNWRAP_OR_PANIC();
In the former (the try-catch version that doesn't try or catch), the lack of handling is silent. It might be fine! You might just depend on your caller using `try`. In the latter, the compiler forces you to use UNWRAP_OR_PANIC (or, in reality, just unwrap) or `data` won't be the expected type and you will quickly get a compile failure.What I suspect you mean, because it's a better argument, is:
try {
sketchy_function1();
sketchy_function2();
sketchy_function3();
sketchy_function4();
} catch (e) {
...
}
which is fair, although how often is it really the right thing to let all the errors from 4 independent sources flow together and then get picked apart after the fact by inspecting `e`? It's an easier life, but it's also one where subtle problems constantly creep in without the compiler having any visibility into them at all.