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).
With return values, you can trivially ignore an exception.
let _ = fs::remove_file("file_doesn't_exist");
or
value, error = some_function()
// carry on without doing anything with error
In the wild, I've seen far more ignoring return errors, because of the mechanical burden of having type handling at every function call.This is backed by decades of writing libraries. I've tried to implement libraries without exceptions, and was my admittedly cargo-cult preference long ago, but ignoring errors was so prevalent among the users of all the libraries that I now always include a "raise" type boolean that defaults to True for any exception that returns an error value, to force exceptions, and their handling, as default behavior.
> In big projects you can basically never know when or how something can fail.
How is this fundamentally different than return value? Looking at a high level function, you can't know how it will fail, you just know it did fail, from the error being bubbled up through the returns. The only difference is the mechanism for bubbling up the error.
Maybe some water is required for this flame war. ;)
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.)
What he seems to be saying is that "obviously in C I would be checking the icon handle for being non-null so clearly error value handling is superior" but this is only obvious to someone knowing the API and checking values for validity has to be done in exception based code too. It's just that exception based code doesn't pretend that it cannot panic somewhere where you don't know. The default, better assumption for programming is that you don't know what this code is doing but it should just work. Unchecked exception handling is the best way to fit that paradigm, you should not have to care about every single line and what it does and constantly sort of almost obsessively check error values of all the APIs you ever use to have this false hope that it cannot panic because you did your duty. No, it can still panic and all this error checking is not helping you program better or more clearly or faster. It swamps the code with so many extra lines that it's practically double the size. All this makes it less clear and that is also what his post shows.