Shared values

Exchange managed values between vocabularies

LanguageKit values give vocabularies a shared data boundary without sharing private syntax trees. The managed Value kinds are null (0), integer (1), text (2), symbol (3), list (4), tuple (5) and opaque (6).

import language-kit
let publish_answer = phrase {
    type = <phrase-types:elaborate>
    action = fn (state:Context*, called:Phrase*) -> void {
        if !LanguageKit:publish_integer(state, "shared_answer", 42) {
            context:diagnostic:error(state, "publication failed")
        }
    }
}
publish_answer
assert shared_answer == 42

publish_integer and publish_text mirror supported values into ordinary runtime bindings. Text publication copies its input. publish promotes a managed value to root ownership so another vocabulary can read it after the current local scope ends.

Values, children and callbacks

Release managed references

Construct values using Value:integer, text_value, symbol_value or new. Release your managed references with Value:release, not free. set_item establishes managed child ownership and rejects cycles. Published bindings keep their own root lifetime; do not release a borrowed lookup as if it were a newly created reference.

Publish and invoke callbacks

publish_callable registers a callback with an arity and userdata. A negative arity accepts any count. invoke returns a managed result in the caller scope or null for an unavailable/invalid call. Define argument validation and value kinds at this boundary; a callback is responsible for the meaning of its result.