Function path_predicate 

pub fn path_predicate(
    doc: &Value<'_>,
    path: &Value<'_>,
) -> Result<Option<bool>, EvalError>

v7.38 (read01, T8) — evaluate a top-level jsonpath boolean predicate like $.a > 3 (the form the @@ operator / jsonb_path_match takes). Returns Some(bool) when the path is a top-level comparison, or None to let the caller fall back to the ordinary path-query match ($.a ? (...) etc.).