Add levenshtein distance based suggestions everywhere

[Manishearth]

Currently, we suggest typo fixes in case of function calls, locals, and field accesses. So, both the marked lines below will suggest the correct fix:

struct A {foo: u8}
fn main() {
    let x = A {foo: 1};
    x.fob; // here
    let aaaaaaa=1;
    let z = aaaaaab; // here
}

However, this is not the case for imports, crates, and inline paths. We should fix this.

This is probably not an easy bug, but should be fun. Basically you need to look for the source of the "could not find X" error, and do something similar to

rust/src/librustc_resolve/lib.rs

Line 3625 in 99925fb

fn find_best_match_for_name(&mut self, name: &str) -> SuggestionType {

@apasel422 @wafflespeanut want to work on this?

[wafflespeanut]

@Manishearth Thanks, I'll try :)

[Manishearth]

Go ahead!

[mitaa]

I was surprised that I didn't get a suggestion here

fn main() {
    "".is_emtpy();
}

[wafflespeanut]

What could one possibly suggest there? :)

[mitaa]

is_empty? (p and t are flipped)

[wafflespeanut]

Hmm, looks like we currently show suggestions only for the stuff that exist in the source file.

[Manishearth]

No, we just don't handle methods.

[cramertj]

Did crate and inline path support ever get added for this? If not, I'd be interested in giving it a shot.

[Manishearth]

I don't think so. Go ahead!

[nikhilshagri]

@Manishearth can I pick this up if nobody else is working on it?