https://github.com/wschella/asynciteratorasync

An AsyncIterator extensions that allows for async closures in utility methods
https://github.com/wschella/asynciteratorasync

Last synced: 6 days ago
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An AsyncIterator extensions that allows for async closures in utility methods

• Host: GitHub
• URL: https://github.com/wschella/asynciteratorasync
• Owner: wschella
• License: mit
• Created: 2018-05-02T09:46:37.000Z (over 6 years ago)
• Default Branch: master
• Last Pushed: 2018-05-02T13:04:01.000Z (over 6 years ago)
• Last Synced: 2024-11-10T08:12:26.811Z (10 days ago)
• Language: TypeScript
• Size: 42 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# AsyncFilterIterator

An AsyncIterator extensions that allows for filtering with Promise based filters.

Use it like this:

```ts

const oldStream: AsyncIterator = whateverAsyncIteratorYouHadBefore;

const filter: (item: T) => Promise = someFilterYouWantToApply;

const newStream = new AsyncFilterIterator(filter, oldStream);

```

The only actual code is this:

```ts

import { AsyncIterator, TransformIterator } from 'asynciterator';

export class AsyncFilterIterator extends TransformIterator {

  constructor(public _filter: (item: T) => Promise, source: AsyncIterator) {

    super({ source });

  }

  _transform(item: T, done: any) {

    this._filter(item)

      .then((result) => (result) ? this._push(item) : undefined)

      .then(() => done())

      .catch((error) => {

        this.emit('error', error);

        done();

      });

  };

}

```