harn-stdlib 0.10.118

Embedded Harn standard library source catalog
Documentation 
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// std/signal — cooperative process interruption helpers.
/**
 * Register a process interrupt handler.
 *
 * @effects: []
 * @errors: []
 */
pub type InterruptOptions = {
  signals?: string | list<string>,
  once?: bool,
  graceful_timeout_ms?: int,
}

pub type InterruptRegistration = {handle: int, signals: list<string>, once: bool}

pub fn on_interrupt(
  handler: fn() -> unknown,
  options: InterruptOptions? = nil,
) -> InterruptRegistration {
  const registration = __signal_on_interrupt(handler, options)
  return {handle: registration.handle, signals: registration.signals, once: registration.once}
}

/**
 * Remove an interrupt handler returned by `on_interrupt`.
 *
 * @effects: []
 * @errors: []
 */
pub fn off_interrupt(handle: int | InterruptRegistration) -> nil {
  return __signal_off_interrupt(handle)
}

/**
 * Return true after the current VM observes an interrupt.
 *
 * @effects: []
 * @errors: []
 */
pub fn interrupted() -> bool {
  return __signal_interrupted()
}

/**
 * Run `body` with an interrupt handler that is always unregistered afterward.
 *
 * @effects: []
 * @errors: []
 */
pub fn with_interrupt<T>(
  handler: fn() -> unknown,
  body: fn() -> T,
  options: InterruptOptions? = nil,
) -> T {
  const registration = on_interrupt(handler, options)
  try {
    const result = body()
    off_interrupt(registration)
    return result
  } catch (e) {
    off_interrupt(registration)
    throw e
  }
}