Iterable Observer

[Observable Proposal][1] implement based on [Async Generator (ES 2018)][2] & [TypeScript][3]

![NPM Dependency][4]
![CI & CD][5]
![][6]

![NPM][7]

Usage

$3

``javascript
import { Observable } from 'iterable-observer';

var count = 0,
list = [];

const observable = new Observable(({ next, complete }) => {
const timer = setInterval(
() => (++count < 5 ? next(count) : complete(count)),
0
);
return () => clearInterval(timer);
});

(async () => {
for await (const item of observable) list.push(item);

console.log(list); // [1, 2, 3, 4, 5]
})();
`

$3

#### Transform events

`javascript
import { Observable } from 'iterable-observer';

const reader = new FileReader(),
{ files } = document.querySelector('input[type="file"]');

reader.readAsBlob(files[0]);

(async () => {
for await (const { loaded } of Observable.fromEvent(reader, 'progress'))
console.log((loaded / file.size) * 100 + '%');
})();
`

#### Transform streams

`typescript
import { Observable } from 'iterable-observer';

(async () => {
const { body } = await fetch('https://example.com/path/to/blob'),
chunks: Uint8Array[] = [];

for await (const chunk of Observable.fromStream(body)) chunks.push(chunk);

const blob = new Blob(chunks);

console.log(blob);
}();
`

$3

`javascript
import { createQueue } from 'iterable-observer';
import Koa from 'koa';
import BodyParser from 'koa-bodyparser';

const { process, observable } = createQueue(),
app = new Koa();

(async () => {
for await (const { defer, data } of observable)
defer.resolve(JSON.stringify(data));
})();

app.use(BodyParser)
.use(async context => (context.body = await process(context.request.body)))
.listen(80);
``

[1]: https://github.com/tc39/proposal-observable
[2]: https://tc39.es/ecma262/#sec-asyncgeneratorfunction-objects
[3]: https://www.typescriptlang.org/
[4]: https://libraries.io/npm/iterable-observer
[5]: https://github.com/EasyWebApp/iterable-observer/actions/workflows/main.yml
[6]: https://www.jsdelivr.com/package/npm/iterable-observer
[7]: https://nodei.co/npm/iterable-observer/