fn instance<'a, 'b>(
path: &'b str,
prefix: &str,
names: impl Iterator<Item = &'a str>,
) -> Option<(&'a str, &'b str)>Expand description
The longest of names the path names after prefix, and the key tail
that follows it.
The longest match is what keeps a name that is a prefix of another
(Beta beside Beta.Two) on its own rows. The corner it cannot
resolve is a name that itself ends in a key-looking segment: with a
beside a.env, the row accounts.a.env.FLAG matches the longer name
and is grouped under a.env. Telling those apart needs the catalogue’s
key set, which a row path does not carry.