1848: Parse `..` as a full pattern r=matklad a=ecstatic-morse
Resolves#1479.
This PR implements [RFC 2707](https://github.com/rust-lang/rfcs/pull/2707) in the parser. It introduces a new `DotDotPat` AST node modeled on `PlaceholderPat` and changes the parsing of tuple and slice patterns to conform to the RFC.
Notably, this PR does *not* change the resulting AST when `..` appears in a struct pattern (e.g. `Struct { a, b: c, .. }`). I *think* this is the behavior mandated by RFC 2707, but someone should confirm this.
Co-authored-by: Dylan MacKenzie <ecstaticmorse@gmail.com>
1847: Allow an underscore as the identifier in `const` items r=matklad a=ecstatic-morse
[RFC 2526](https://github.com/rust-lang/rust/issues/54912) was recently stabilized, meaning `const _: i32 = 5;` is now a valid item.
Co-authored-by: Dylan MacKenzie <ecstaticmorse@gmail.com>
Nameres related types, like `PerNs<Resolution>`, can represent
unreasonable situations, like a local in a type namespace. We should
clean this up, by requiring that call-site specifies the kind of
resolution it expects.
1821: Macro completion tweaks r=matklad a=SomeoneToIgnore
Thanks @uHOOCCOOHu for making the macro completion happen :)
I've added a few tweaks to the current completion to make it a bit more convenient:
* Automatically add braces and put the editor cursor inside of them:
<img width="159" alt="image" src="https://user-images.githubusercontent.com/2690773/64737220-022b9f00-d4f5-11e9-8088-76d4678921ab.png">
Currently I have to add the braces manually which is a bit cumbersome.
One further improvement can be to detect if macro accepts no parameters and place the cursor differently for this case.
* Add an exclamation mark to the macro completion label
This helps to distinguish macros from other completion items and also allows to show only macros in completion if you type `!`:
<img width="722" alt="image" src="https://user-images.githubusercontent.com/2690773/64736987-8b8ea180-d4f4-11e9-8355-2ce4f83b7aa8.png">
<img width="732" alt="image" src="https://user-images.githubusercontent.com/2690773/64737214-ffc94500-d4f4-11e9-946e-1ba2db1c7fb1.png">
Additionally, automatic formatting hooks had adjusted two `help.rs` files, I've added them as a last commit to the PR even though they are not really related.
Co-authored-by: Kirill Bulatov <mail4score@gmail.com>
Parser has the invariant that `{}` are balanced.
Previous code tried (unsucesfuly) maintain the same invariant for
`$()` as well, but it was done in a rather ad-hoc manner: it's not at
all obvious that it is possible to maintain both invariants!
