rustdoc-search: add support for nested generics

[notriddle]

This change allows search.js to parse nested generics (which look Like<This<Example>>) and match them. It maintains the existing "bag semantics", so that the order of type parameters is ignored but the number is required to be greater than or equal to what's in the query.

For example, a function with the signature fn read_all(&mut self: impl Read) -> Result<Vec<u8>, Error> will match these queries:

• Read -> Result<Vec<u8>, Error>
• Read -> Result<Error, Vec>
• Read -> Result<Vec<u8>>

But it does not match Result<Vec, u8> or Result<u8<Vec>>.

[rustbot]

Some changes occurred in HTML/CSS/JS.

cc @GuillaumeGomez, @Folyd, @jsha

[GuillaumeGomez]

It will need an FCP. Also, could you update the documentation and the help in the rustdoc pages to include this please?

[notriddle]

@GuillaumeGomez I added a description of generic-matching semantics to the rustdoc book.

The ? button doesn't mention generics at all, and I'm not sure there's need to add it, but I did find a mistake in there and will open a separate pull request to update it.

[notriddle]

@rfcbot fcp merge

[rfcbot]

Team member @notriddle has proposed to merge this. The next step is review by the rest of the tagged team members:

• @GuillaumeGomez
• @Manishearth
• @Nemo157
• @aDotInTheVoid
• @camelid
• @jsha
• @notriddle

No concerns currently listed.

Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

See this document for info about what commands tagged team members can give me.

[rfcbot]

🔔 This is now entering its final comment period, as per the review above. 🔔

[bors]

☔ The latest upstream changes (presumably #110324) made this pull request unmergeable. Please resolve the merge conflicts.

[rfcbot]

The final comment period, with a disposition to merge, as per the review above, is now complete.

As the automated representative of the governance process, I would like to thank the author for their work and everyone else who contributed.

This will be merged soon.

[GuillaumeGomez]

r=me once CI pass

[notriddle]

@bors r=GuillaumeGomez rollup

[bors]

📌 Commit 6ce5327 has been approved by GuillaumeGomez

It is now in the queue for this repository.

[bors]

⌛ Testing commit 6ce5327 with merge 3312a30...

[bors]

☀️ Test successful - checks-actions
Approved by: GuillaumeGomez
Pushing 3312a30 to master...

[rust-timer]

Finished benchmarking commit (3312a30): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-5.5%	[-5.5%, -5.5%]	1
All ❌✅ (primary)	-	-	0

Cycles

This benchmark run did not return any relevant results for this metric.