[rust-analyzer] Workspace symbol picker should search the same symbol types as the single-file symbol picker

[willhansen]

The Problem

With rust, the workspace symbol picker and the single-file symbol picker have different search behavior, even with a single file in the project. This is unintuitive, and the default behavior should be that they are the same.

• The workspace symbol picker does not return any function names unless there are absolutely no struct names that fuzzy match the given string.
• The single-file symbol picker searches both from the beginning

Reproduction:

With a file generated by this python script:

#!/usr/bin/env python3

n = 300
with open("main.rs", "w") as file:
    file.write('fn main() {println!("asdf");}\n')
    for i in range(n):
        file.write('fn a' + str(i) + '_snake_func() {println!("asdf");}\n')
        file.write('fn a' + str(i) + 'CamelFunc() {println!("asdf");}\n')
        file.write('struct a' + str(i) + '_snake_struct();\n')
        file.write('struct a' + str(i) + 'CamelStruct();\n')

Workspace symbol picker:

Single-file symbol picker:

The Fix

This can by fixed with this language.toml file, making both symbol pickers include functions from the beginning:

[[language]]
name = "rust"

[language.config.workspace.symbol.search]
kind = "all_symbols"

This should be set by default.

(continued from discussion: #7867)

[pascalkuthe]

There seem to be some performance concerns about changing the default rust-lang/rust-analyzer#14553 (comment).

You can also append # to search for functions too. It doesn't currently work in helix but #7265 will fix that. I think we should stick with the RA default. Whether a different default is the better choice or not should be discussed and changed upstream instead of here.

In the meantime adding this t your personal config is a very simple workaround