Interface Fetcher

14-adv-subscription/main.go:14–16

A Fetcher fetches Items and returns the time when the next fetch should be attempted. On failure, Fetch returns a non-nil error.

// A Fetcher fetches Items and returns the time when the next fetch should be
// attempted.  On failure, Fetch returns a non-nil error.
type Fetcher interface {
	Fetch() (items []Item, next time.Time, err error)
}

// A Subscription delivers Items over a channel.  Close cancels the
// subscription, closes the Updates channel, and returns the last fetch error,