Some monaco docs

Taking control of the cursor

Some functions

(editor:Editor) => editor['cursor'].trigger('jumpy','cursorLeft'),
(editor:Editor) => editor['cursor'].trigger('jumpy','cursorDown'),
(editor:Editor) => editor['cursor'].trigger('jumpy','cursorRight'),
(editor:Editor) => editor['cursor'].trigger('jumpy','cursorUp'),

Completions Sorting

In Suggest.ts : determines the overall sorting of completion items : https://github.com/Microsoft/vscode/blob/1889442ff090ef8170814a98698506300962dbba/src/vs/editor/contrib/suggest/common/suggest.ts#L142

Then in completionModel.ts _createCachedState : https://github.com/Microsoft/vscode/blob/1889442ff090ef8170814a98698506300962dbba/src/vs/editor/contrib/suggest/common/completionModel.ts#L110 filters these into filteredItems

_createCachedState also stores the _topScoreIdx and that is used to set the focus as the completion model comes up.