pub fn unit_name_at(source: &str, offset: usize) -> Option<String>Expand description
#1885: the qualified unit name under offset, when the cursor sits on the
file’s own unit-header name or on a uses/consumes (or a suite’s) target
path — the positions where hover shows a unit’s module doc.
The match is on the name’s byte range (start..=end), never on Span
equality, so it holds for a buffer re-parsed with FileId::UNKNOWN. Every
segment of a dotted path answers with the whole name: the cursor on
model in uses compat.model names compat.model, not a model.