O’REILLY Learning「Asynchronous Programming with SwiftUI and Combines」2. Getting Started with SwiftUI
https://learning.oreilly.com/library/view/asynchronous-programming-with/9781484285725/
2. Getting Started with SwiftUI
「Composing a View for Displaying a Book」をまず作ってみる
最後は「Refactoring the Code Using Extract Subview」でリファクタリング
基本的な部品を使用して体験という学習本の入り口の章。