`DataLoadState` sketch.

data_load_state.swift

enum DataLoadState<Value, Error: Swift.Error> {
	case initial
	case loading
	case loaded(Value)
	case error(Error) /// (1) A challenging exercise for the reader is to think through extending
	/// this type to support paginated loadings.

	var isLoading: Bool { /// (2) Again, taking cue from Point Free’s enumeration properties work.
		/// This will be helpful when enabling and disabling buttons while a request is in-flight.
		switch self {
		case .loading:
			return true
		default:
			return false
		}
	}
}