once

function once<Args extends readonly unknown[], Out, E, R>(
  event: Event<Args, Out, E>,
  handler: (...args: NoInfer<Args>) => Effect<NoInfer<Out>, NoInfer<E>, R>,
  options?: HandlerOptions,
): Effect<void, never, Scope | Graft | R>

Defined in: Event.ts:202

Registers a handler that runs at most once, even if it dispatches the event again. Its registration detaches from the owner after execution and cancellation cleanup.

Type Parameters

Type Parameter
Args extends readonly unknown[]
Out
E
R

Parameters

Parameter	Type
event	Event<Args, Out, E>
handler	(…args: NoInfer<Args>) => Effect<NoInfer<Out>, NoInfer<E>, R>
options?	HandlerOptions

Returns

Effect<void, never, Scope | Graft | R>