Clean up syntax for importing and using nested type declarations

Search Terms

• import
• import equals
• nested import

Suggestion

The current syntax for importing nested modules is confusing. For example, to specifically use a single property from an interface I would need to do something like this:

// interface.ts
interface Example {
    Foo: string
}

// file.ts
import { Example } from 'interface.ts';
import Foo = Example.Foo // this is weird, as I'm not actually importing any resource here

From what I understand, import is not importing anything here. It's confusing and looks like it's doing something totally different at first glance. In this case, I could also use type Bind = interfaces.Bind, but I don't want to create a new resource.

A much nicer syntax would be adding a use or take keyword, or adding support for importing nested modules

Use Cases

This suggestion is just for readability and developer experience.

Examples

Importing nested modules with use or take

// interface.ts
interface Example {
    Foo: string
}

// file.ts
import { Example } from 'interface.ts';
take { Foo } from Example;

importing nested interface/namespace values:

// interface.ts
interface Example {
    Foo: string
}

// file.ts
import { Example: { Foo } } from 'interface.ts';

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.

interface.ts と file.ts にあるネストされた宣言の例を確認します。既存の import-equals 形式と、提案されている use、take、nested-import 形式も含めます。実装を検討する前に、意図された構文と型チェックの動作を明確にします。完了とするには、合意された設計とコンパイラーおよびリグレッションテストが必要になりますが、issue ではそのいずれも特定されていません。