[Merged by Bors] - Fix start position on class declarations with decorators

[dsherret]

Fixes: #626 (comment)

See #581

[dsherret]

This is being passed in on line 90.

[kdy1]

bors r+

[kdy1]

Thanks!

[bors]

Build succeeded

• continuous-integration/travis-ci/push

[bors]

Pull request successfully merged into master.

[dsherret]

Thanks @kdy1 and that's awesome you implemented top level await so fast!

Would it be possible to get a release for swc_ecma_parser sometime you find the chance?

[kdy1]

@dsherret I publised it. Note that you need to update swc_common too.

[dsherret]

Thanks a lot @kdy1 !

I'm wondering how to get the byte position and comment vector pairs out of the RefMulti in the DashMap though. Any ideas? If not, I will sadly clone for now (edit: or determine whether cloning or just reading from this map is faster).

let (leading_comments, trailing_comments) = comments.take_all();
// previously did something like this:
let leading_comments: HashMap<BytePos, Vec<Comment>>
    = leading_comments.into_iter().collect();

[kdy1]

@dsherret
DashMap does not support taking all value, but you can use iter_mut with std::mem::replace.
Iterate over a dashmap with iter_mut(), and replace the value with

replace( item..value_mut(), Default::default())

[dsherret]

@kdy1 awesome idea. Thanks! 🙂

[dsherret]

Hmmm... couldn't figure it out then tried to just use CommentMap in my code to see how it performs, but ran into some issues. I just went back to cloning for now :(

Only slightly slower so no big deal! I'll look into this later.