|
- /**
- Get the element type of an `Iterable`/`AsyncIterable`. For example, an array or a generator.
-
- This can be useful, for example, if you want to get the type that is yielded in a generator function. Often the return type of those functions are not specified.
-
- This type works with both `Iterable`s and `AsyncIterable`s, so it can be use with synchronous and asynchronous generators.
-
- Here is an example of `IterableElement` in action with a generator function:
-
- @example
- ```
- function * iAmGenerator() {
- yield 1;
- yield 2;
- }
-
- type MeNumber = IterableElement<ReturnType<typeof iAmGenerator>>
- ```
-
- And here is an example with an async generator:
-
- @example
- ```
- async function * iAmGeneratorAsync() {
- yield 'hi';
- yield true;
- }
-
- type MeStringOrBoolean = IterableElement<ReturnType<typeof iAmGeneratorAsync>>
- ```
-
- Many types in JavaScript/TypeScript are iterables. This type works on all types that implement those interfaces. For example, `Array`, `Set`, `Map`, `stream.Readable`, etc.
-
- An example with an array of strings:
-
- @example
- ```
- type MeString = IterableElement<string[]>
- ```
- */
- export type IterableElement<TargetIterable> =
- TargetIterable extends Iterable<infer ElementType> ?
- ElementType :
- TargetIterable extends AsyncIterable<infer ElementType> ?
- ElementType :
- never;
|