Struct ActionHandlerRegistry 

pub struct ActionHandlerRegistry { /* private fields */ }

Wait-free registry of mode-contributed action handlers.

Stored behind an Arc and shared by reference: the host’s chord dispatcher reads via lookup; modes register via register during Mode::on_activate and unregister via the returned ActionHandlerRegistration token’s Drop impl.

Examples

The per-buffer path: a mode registers in on_activate and keeps the token in its Guard, so deactivation unregisters the body.

use std::sync::Arc;
use lattice_grammar::effect::{EchoLevel, Effect};
use lattice_mode::{ActionHandler, ActionHandlerRegistry};
use lattice_protocol::ids::CommandId;

let registry = Arc::new(ActionHandlerRegistry::new());
let refresh = CommandId::new(41); // resolved from "action:weather-refresh"

let body: ActionHandler = Arc::new(|ctx| {
    let text = format!("refreshing buffer {}", ctx.buffer_id);
    Some(Effect::Echo { level: EchoLevel::Info, text })
});
let token = registry.register(refresh, body); // lives in the mode's Guard
assert!(registry.lookup(refresh).is_some());

drop(token); // the Guard dropped: the mode deactivated
assert!(registry.lookup(refresh).is_none());

Implementations

impl ActionHandlerRegistry

pub fn new() -> Self

Construct an empty registry.

pub fn register( self: &Arc<Self>, action_id: CommandId, handler: ActionHandler, ) -> ActionHandlerRegistration

Register an action handler closure for action_id. Returns an RAII registration token; the token’s Drop impl unregisters the handler. Modes accumulate tokens in their Guard so deactivation drops them and the chord falls through to “unhandled” naturally.

If a handler is already registered for action_id, the new closure replaces it. (Modes shouldn’t collide on CommandId in normal usage — IDs are per-action and modes register distinct sets — but the last-write-wins semantics keeps the substrate behavior well-defined.)

pub fn lookup(&self, action_id: CommandId) -> Option<ActionHandler>

Wait-free lookup. Returns a cloned Arc of the handler closure (cheap — Arc::clone is one atomic increment). The host’s chord dispatcher calls this once per chord resolution; calling the returned handler is a direct Fn invocation.

Trait Implementations

impl Debug for ActionHandlerRegistry

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ActionHandlerRegistry

fn default() -> Self

Returns the “default value” for a type.