One-shot continuation using symmetric coroutines

index.js

const coro = require('symcoro');
const {create, transfer} = coro;

// Figure 4. Implementing one-shot continuations with symmetric coroutines
// http://www.inf.puc-rio.br/~roberto/docs/MCC15-04.pdf

function* call1cc(f) {
  // save the continuation "creator"
  let currentCoro = coro.current;

  // invoking the continuation transfers control
  // back to its creator
  function* cont(val) {
    if (currentCoro === null) {
      throw new Error('one shot continuation called twice');
    }
    yield* coro.transfer(currentCoro, val);
  }

  const val = yield* coro.transfer(
    coro.create(function*() {
      const v = yield* f(cont);
      yield* cont(v);
    })
  );

  // when control is transfered back, the continuation
  // was "shot" and must be invalidated
  currentCoro = null;

  // the value passed to the continuation
  // is the return value of call1/cc
  return val;
}

coro.run(function*() {
  return yield* call1cc(function*(cont) {
    yield* transfer(create(function* nested() {
      yield* transfer(create(function* nestedAgain() {
        yield* cont(42);
      }));  
    }));
  });
}, console.log); //42