Interface Progress

meter/meter.go:20–25

Progress is an interface for a simple progress meter. Call `Start()` to begin reporting. `format` should include some kind of '%d' field, into which will be written the current count. A spinner and a CR character will be added automatically. Call `Inc()` every time the quantity of interest increase

// been called, it may be reused (starting at value 0) by calling
// `Start()` again.
type Progress interface {
	Start(format string)
	Inc()
	Add(delta int64)
	Done()
}

// Spinners is a slice of short strings that are repeatedly output in
// order to show the user that we are working, before we have any