bookmark: Add bookmark support

[CharlesChen0823]

Currently bookmark can work, and had something not done.
Want to get some feedback and suggestion.

Release Notes:

• Add bookmark support

[ConradIrwin]

Thanks for this!

I think bookmarks should be based on Anchors, not on row/column, so that as the code is edited the bookmarks stay in the "same place". In order to make this work reliably, we'd either have to ensure that creating a bookmark keeps the file open, so the Bookmark might end up being struct Bookmark{ buffer: Model<Buffer>, anchor: text::Anchor }.

We also need to think about multi-buffers. If you create a book mark from a project search, and then go to that bookmark, should it take you to that position in the underlying buffer, or in the multibuffer?

[CharlesChen0823]

I think bookmarks should be based on Anchors, not on row/column, so that as the code is edited the bookmarks stay in the "same place".

I think there is an use case, we cannot easy toggle the bookmark remove, if we based on Anchors.

In order to make this work reliably, we'd either have to ensure that creating a bookmark keeps the file open

I had check some other implementation, IMO, bookmarks should exist even if the current buffer is closed, if using Modal<Buffer> to represent bookmark, we should keep buffer always opened?

[ConradIrwin]

I think removing Anchors can still work, you just need to convert the anchor back to a point when checking?

If we retain the buffer in the bookmark store as a Model<Buffer> it will stay in memory even if the editor is closed. The alternative would be to convert between anchors and row/column when the buffer is closed - which you may want to do if you want bookmarks to persist when the workspace is closed and reopened.

[CharlesChen0823]

I think removing Anchors can still work, you just need to convert the anchor back to a point when checking?

I don't mean user cannot can remove bookmark, I thought when user toggle remove a bookmark, he should first find the correct point, then can remove it. It's not better UX.

If we retain the buffer in the bookmark store as a Model<Buffer> it will stay in memory even if the editor is closed. The alternative would be to convert between anchors and row/column when the buffer is closed - which you may want to do if you want bookmarks to persist when the workspace is closed and reopened.

Ahh, thanks, i'm misunderstood.

I will convert using Modal<Buffer>

[SomeoneToIgnore]

This looks quite stale, so I'll close this.