Of
What a span is of: a definition (its hash) by its name now, or, no longer named (gone): if a version named now
replaced it, an earlier version of that definition, by its name (earlier: changed since, not renamed or
removed); if not, by the name it had. A page's or a statement's (no hash) by its name.
export interface Of { hash: string | null; label: string; gone: boolean; earlier?: boolean; }