type destructuring

Search Terms

type destructuring

Suggestion

Allow destructuring syntax when assigning type

Use Cases

Dynamically assign a type as the type of an other type's property.

Examples

Where AutocompleteService is a class, PlacesServiceStatus is an enum, and AutocompletePrediction is an interface.

What I'm doing currently:

const { AutocompleteService, PlacesServiceStatus } = google.maps.places;
type AutocompletePrediction = google.maps.places.AutocompletePrediction;

What I'd like to be able to do:

const { AutocompleteService, PlacesServiceStatus } = google.maps.places;
type { AutocompletePrediction } = google.maps.places;

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

この Issue では、型代入で分割代入構文を使用できるようにすることを提案しており、望ましい形式を示す TypeScript の例が提示されています。実装ファイル、エントリーポイント、テストは指定されていません。まず TypeScript が型エイリアスをどのように解析してチェックするかを追跡し、次に有効な型の分割代入と既存の構文を区別するテストを定義してください。例が出力される JavaScript を変更せずに型チェックを通れば完了です。