Doc.CompletionSourcetype t = private | Yes of Lang.Range.tLocation of the last token in the document
*)| Stopped of Lang.Range.tLocation of the last valid token before stopping
*)| WorkspaceUpdated of Lang.Range.tThe Workspace Environment was updated when document was processed up to the range. Document may need full re-check from the beginning.
*)| Failed of Lang.Range.tCritical failure, like an anomaly
*)