regex-automata VS KEEP

I believe you're the second person to tell me they were confused by this, so there are probably several others confused but didn't say anything. I've added a warning to the top of regex-automata's README.

For anyone following along at home, we're having a very helpful discussion about the implementation I posted in my sibling comment here: https://github.com/BurntSushi/regex-automata/issues/30

My current technique only gets applied to alternations of simple literals. But the idea is generalizeable and I speculate that it is actually impactful to generalize it.

(I could use '_ => {}' instead of 'None' to save a few more.)

I do find the 'if let' variant to be a bit easier to read. It's optimizing for a particular and somewhat common case, so it does of course overlap with 'match'. But I don't find this particular overlap to be too bad. It's usually pretty clear when to use one vs the other.

But like I said, I could live without 'if let'. It is not a major quality of life enhancement to me. Neither will its impending extensions. i.e., 'if let pattern = foo && some_booolean_condition {'.

[1]: https://github.com/BurntSushi/regex-automata/blob/fbae906823...

[2]: https://github.com/BurntSushi/regex-automata/blob/fbae906823...

(The work on regex-automata 0.2 has been underway for over a year now.](https://github.com/BurntSushi/regex-automata/tree/ag/work) There's a lot done, but still a lot more to go. Once that's done, regex proper should be pretty close to a thin layer that glues regex-syntax, regex-automata, memchr and aho-corasick together. I don't currently expect regex to grow any more dependencies than that. And as it is, aho-corasick and memchr are both optional dependencies. Right now, regex-syntax is the only required dependency, but regex-automata will be added to that list.

`Either foo()` and `Foo foo() throws MyError` and are pretty much isomorphic.

https://github.com/Kotlin/KEEP/blob/master/proposals/stdlib/...

Nice. So for example, it looks like Kotlin has a nearly identical feature at the language level which will be optimizable when Valhalla ships: https://github.com/Kotlin/KEEP/blob/master/notes/value-class...

> In the future, in a Valhalla-capable JVM, JVM primitive classes will enable efficient representation of Kotlin value classes with an arbitrary number of underlying fields on JVM.

Most other languages agree that checked exceptions are not good by not having them.

As for alternatives, Try/Result and similar monads have decent adoption even in Java, but personally I quite like the Kotlin philosophy [1] to not have generic error containers and either use runtime exceptions or make failures of the return type.

[1] https://github.com/Kotlin/KEEP/blob/master/proposals/stdlib/...

If you want to read more and don't want to google it: https://github.com/Kotlin/KEEP/blob/data-objects/proposals/data-objects.md

Under the hood: https://github.com/Kotlin/KEEP/blob/master/proposals/coroutines.md .

you can check more here

You can use explicit API mode, then everything needs explicit visibility