(Anonymous)

Gets the eventual value of the task as a JavaScript's Promise.

Since Promises don't have support for representing cancellations, Folktale's tasks represent cancellation as a rejection with a special object. See the documentation for Futures and Deferreds for more details.

Example:

const { task, of, rejected } = require('folktale/concurrency/task');

const result1 = await of(1).run().promise();
$ASSERT(result1 == 1);

try {
  const result2 = await rejected(1).run().promise();
  throw 'never happens';
} catch (error) {
  $ASSERT(error == 1);
}

try {
  const result3 = await task(r => r.cancel()).run().promise();
  throw 'never happens';
} catch (error) {
  const { Cancelled } = require('folktale/concurrency/future/_execution-state');
  $ASSERT(Cancelled.hasInstance(error));
}