Function path 

pub fn path(segments: &[&str]) -> PathPat

A dotted path pattern: * means “any key at this depth” (fields.*.type), [] means “each item of this sequence” (audiences.[].name).

The two are not interchangeable and the difference is easy to get wrong in the silent direction: an * against a sequence matches nothing, governs nothing, and reports no error — the rows simply come out untyped.