Crate pamoja_zenoh 

Zenoh key-expression logic and transport for the pamoja SDK.

Zenoh addresses data by key expressions: /-joined chunks with a small, exact wildcard language. Before any session is opened, a node has to know whether a key is well-formed, what its one canonical spelling is, whether a subscription pattern matches a published key, and how two patterns relate. That is pure string logic with no I/O, and getting it wrong silently drops or misroutes messages, so it lives here as checked logic anchored to the Zenoh specification and tested against Zenoh’s own implementation.

See keyexpr for the rules and the operations:

• validity: a key expression is /-joined non-empty chunks with no leading, trailing, or doubled /, where * and ** are whole-chunk wildcards and $* is a sub-chunk wildcard. A chunk that starts with @ is verbatim, and no wildcard selects it.
• canonical form: two expressions that select the same keys share one spelling, so equality is a string comparison; canonize produces it, and a Zenoh session accepts nothing else. join builds a key beneath a prefix in that form.
• matching: matches tests whether a concrete key is selected by a pattern, the routing question a subscriber asks of every publication.
• relations: intersects tests whether two patterns share a key, and includes whether one covers every key of another, the questions a router and a bridge ask of two subscriptions.

With the runtime feature on, ZenohTransport adds the live half: it opens a Zenoh session and implements the core Transport, so Zenoh becomes the efficient edge-to-edge and fleet transport behind the same surface as every other link.

Examples

use pamoja_zenoh::keyexpr::{canonize, includes, intersects, matches};

// A subscription with a single-chunk wildcard selects a matching publication.
assert!(matches("room275/*/temperature", "room275/device1/temperature"));
assert!(!matches("room275/*/temperature", "room275/temperature"));

// `**/*` is valid but not canonical; its one canonical spelling puts the `*` first.
assert_eq!(canonize("robot/sensor/**/*").as_deref(), Some("robot/sensor/*/**"));

// Two patterns overlap when some key belongs to both, and one covers the other when every
// key of the second belongs to the first.
assert!(intersects("room275/*/temperature", "room275/device1/**"));
assert!(includes("room275/**", "room275/*/temperature"));

Modules

keyexpr

The Zenoh key-expression language: validity, canonical form, matching, and the relations between two expressions.