I think it's time to address the elephant in the room.
This Pull Request will (hopefully!) solve part of #736.
This is a complete rewrite of `JsString`, but instead of storing `u8` bytes it stores `u16` words. The `encode!` macro (renamed to `utf16!` for simplicity) from the `const-utf16` crate allows us to create UTF-16 encoded arrays at compilation time. `JsString` implements `Deref<Target=[u16]>` to unlock the slice methods and possibly make some manipulations easier. However, we would need to create our own library of utilities for `JsString`.
This PR fixes#2275
There are keywords that are allowed as identifiers.
https://tc39.es/ecma262/#sec-keywords-and-reserved-words
> Those that are always allowed as identifiers, but also appear as keywords within certain syntactic productions, at places where Identifier is not allowed: as, async, from, get, meta, of, set, and target.
This PR adds test cases for them, and fixes some cases such as
`class A { set(a, b) { } }`
`function of() { }`
`let obj = {async: true}`
`async()`
This Pull Request changes the following:
- Modify `CreateDynamicFunction` to work with generator functions.
- Add the name `anonymus` to functions created via `CreateDynamicFunction` to comply with the spec.
- Fix a bug in the `Yield` parser where the parser would expect a token when no token is a legal case.
- Change the `Yield::new` function to require less turbofishes.
So, @raskad and myself had a short discussion about the state of #736, and we came to the conclusion that it would be a good time to implement our own string interner; partly because the `string-interner` crate is a bit unmaintained (as shown by https://github.com/Robbepop/string-interner/pull/42 and https://github.com/Robbepop/string-interner/pull/47), and partly because it would be hard to experiment with custom optimizations for UTF-16 strings. I still want to thank @Robbepop for the original implementation though, because some parts of this design have been shamelessly stolen from it 😅.
Having said that, this PR is a complete reimplementation of the interner, but with some modifications to (hopefully!) make it a bit easier to experiment with UTF-16 strings, apply optimizations, and whatnot :)
This Pull Request fixes/closes #337.
It changes the following:
- Implement class declaration parsing.
- Implement class expression parsing.
- Implement class execution.
There are still some features like `super` missing and there are some early errors that are not implemented yet. But I think it makes sense to merge this, as we can branch out the missing features from here.
This removes all the calls to `unwrap()` in the codebase, which made me found a couple of places where it wasn't needed, and could be improved. I also noticed we don't have dependabot updates for the test262 submodule and the interner dependencies, so I added those.
I added lints so that no new unwraps are added.
This PR adds some Clippy lints. Mainly, it adds the list of pedantic lints excluding some lints that were causing too many warnings. I also denied some useful restriction and pedantic lints, to make sure we use `Self` all the possible times (for better maintainability), and that we pass elements by reference where possible, for example, or that the documentation is properly written.
This might even have some small performance gains.
I also added a perfect hash function for the CLI keywords, which should be more efficient than a `HashSet`. This is something we could use elsewhere too.
This builds on top of #1758 to try to bring #1763 to life.
Something that should probably be done here would be to convert `JsString` to a `Sym` internally. Then, further optimizations could be done adding common strings to a custom interner type (those that we know statically).
This is definitely work in progress, but I would like to have feedback on the API, and feel free to contribute.
Co-authored-by: raskad <32105367+raskad@users.noreply.github.com>
This Pull Request is part of #279.
It adds a string interner to Boa, which allows many types to not contain heap-allocated strings, and just contain a `NonZeroUsize` instead. This can move types to the stack (hopefully I'll be able to move `Token`, for example, maybe some `Node` types too.
Note that the internet is for now only available in the lexer. Next steps (in this PR or future ones) would include also using interning in the parser, and finally in execution. The idea is that strings should be represented with a `Sym` until they are displayed.
Talking about display. I have changed the `ParseError` type in order to not contain anything that could contain a `Sym` (basically tokens), which might be a bit faster, but what is important is that we don't depend on the interner when displaying errors.
The issue I have now is in order to display tokens. This requires the interner if we want to know identifiers, for example. The issue here is that Rust doesn't allow using a `fmt::Formatter` (only in nightly), which is making my head hurt. Maybe someone of you can find a better way of doing this.
Then, about `cursor.expect()`, this is the only place where we don't have the expected token type as a static string, so it's failing to compile. We have the option of changing the type definition of `ParseError` to contain an owned string, but maybe we can avoid this by having a `&'static str` come from a `TokenKind` with the default values, such as "identifier" for an identifier. I wanted for you to think about it and maybe we can just add that and avoid allocations there.
Oh, and this depends on the VM-only branch, so that has to be merged before :)
Another thing to check: should the interner be in its own module?
José Julián Espina
raskad
Choongwoo Han
Iban Eguia