Setting `rust-analyzer.workspace.symbol.search.scope` to `workspace_and_dependencies` produces bad results

[thomaseizinger]

I am a VSCode user and I just learned about rust-analyzer.workspace.symbol.search.scope. Searching types from dependencies has been one of the features I really missed from IntelliJ.

Unfortunately, it appears that it is almost unusable in its current form. I am not sure what the sorting order is but it appears to be entirely random. I've also set rust-analyzer.workspace.symbol.search.scope to all_symbols and even when typing an exact symbol name from my local workspace, VSCode shows fuzzy-matched results from some my dependencies:

I think the results should be sorted by "distance" to the currently open file:

• Matches in the local workspace
• Matches in direct dependencies of the current crate
• Matches in direct dependencies of any workspace crate
• Matches in transitive dependencies

An MVP of the above could be to just prioritize workspace matches over dependency ones although I do think getting the order of results from dependencies right is also key.

A somewhat obvious one is also that full or at least partial matches should be prioritized over fuzzy-matched ones.

[asartamonov]

Great point actually. But there is an issue with VSCode itself - it filters out special symbols * and # which could be used to narrow down results from 'dependencies' to 'local workspace' (see rust-analyzer manual https://rust-analyzer.github.io/manual.html#workspace-symbol). I also see an issue with searching fuzzyness as although we have SearchMode::Exact along with SearchMode::Fuzzy, there is no way to switch it when searching symbols, it is SearchMode::Fuzzy by default and no user api to change it, as long as I see in src (https://github.com/rust-lang/rust-analyzer/blob/master/crates/ide-db/src/symbol_index.rs#L48) no way to interact with 'exact(&mut self)' method for a user. SearchMode::Exact is default resolution strategy for imports only, not customisable also.

It would be great to have some .. special symbol (?) like ? or ! to customise fuzzyness behaviour? ?Foo* - fuzzy search Foo in dependencies !Foo* - exact search Foo in dependencies But again, what VSCode users can do with special symbols.

[Veykril]

Indeed, we can barely do anything with the feature as it stands right now, as VSCode has this implemented very weakly for the LSP protocol.

[thomaseizinger]

Great point actually. But there is an issue with VSCode itself - it filters out special symbols * and # which could be used to narrow down results from 'dependencies' to 'local workspace'

i don't understand what special symbols have to do with narrowing down the search. I don't actually want any special symbols to tweak the search. Instead, results should be sorted such that the most relevant ones come first (for example, based on likelihood I listed above).

Some more notes on what IntelliJ does (which I think works really well):

• Using all upper case letters matches camel-case letters: If there exists a symbol FooBarBaz and I search for FBB, it should rank reasonably high because of: FooBarBaz
• Search for files vs symbols should be split. This already works by searching with # prefix vs not. This makes sense because those are two different namespaces of things I am searching for.
• Always fuzzy-match but prefer exact matches over non-exact ones

So, in summary I think we have a ranking problem here. The current search results are "correct" in that there is a (fuzzy) match. They are just not ranked in a useful order.