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.

Review the nested declaration examples in interface.ts and file.ts, including the existing import-equals form and the proposed use, take, and nested-import forms. Determine the intended syntax and type-checking behavior before considering implementation; done would require an agreed design plus compiler and regression tests, none of which are identified in the issue.