pub fn map_selector(
  a: process.Selector(a),
  b: fn(a) -> b,
) -> process.Selector(b)

pub fn merge_selector(
  a: process.Selector(a),
  b: process.Selector(a),
) -> process.Selector(a)

pub fn monitor(
  self self: process.Pid,
  pid pid: process.Pid,
) -> process.Monitor

pub fn new() -> #(process.Subject(a), process.Subject(a))

pub fn new_selector() -> process.Selector(a)

pub fn recv(recv: process.Subject(a)) -> a

pub fn select(
  selector: process.Selector(a),
  for receiver: process.Subject(a),
) -> process.Selector(a)

pub fn select_map(
  selector: process.Selector(a),
  for receiver: process.Subject(b),
  mapping transform: fn(b) -> a,
) -> process.Selector(a)

pub fn select_monitors(
  selector: process.Selector(payload),
  mapping: fn(process.Pid) -> payload,
) -> process.Selector(payload)

pub fn select_specific_monitor(
  selector: process.Selector(payload),
  monitor: process.Monitor,
  mapping: fn(process.Pid) -> payload,
) -> process.Selector(payload)

pub fn selector_recv(
  self self: process.Pid,
  from from: process.Selector(a),
) -> a

pub fn send(send: process.Subject(a), x: a) -> Nil

pub fn spawn_unlinked(
  a: fn(process.Pid) -> anything,
) -> process.Pid