class WritableIterable
implements Writable<T>, AsyncIterable<T>

Invert data flow: push writes on one side, iterate on the other.

WritableIterable bridges the gap between push-based (write) and pull-based (iterate) programming models. It's useful when you need to feed data into an AsyncIterable from imperative code.

Important: You must call close() when done writing, or iteration will hang.

Why use this?

  • Convert callback-based APIs to AsyncIterable
  • Feed data to process stdin programmatically
  • Bridge between different async patterns
  • Proper error propagation

Examples

Basic usage

import { WritableIterable } from "jsr:@j50n/proc";

const writable = new WritableIterable<number>();

// Write in background
(async () => {
  await writable.write(1);
  await writable.write(2);
  await writable.write(3);
  await writable.close();
})();

// Read
for await (const item of writable) {
  console.log(item);
}

Error propagation

import { WritableIterable } from "jsr:@j50n/proc";

const writable = new WritableIterable<number>();

(async () => {
  await writable.write(1);
  await writable.close(new Error("something failed"));
})();

try {
  for await (const item of writable) {
    // Process items
  }
} catch (error) {
  console.error("Error:", error);
}

Constructors

new
WritableIterable(options?: { onclose?: () => void | Promise<void>; })

Create a new PushIterable.

Type Parameters

Properties

private
_closed: boolean
readonly
isClosed: boolean
private
queue: QueueEntry<Some<T> | None>[]

Methods

[Symbol.asyncIterator](): AsyncIterator<T>

It is an AsyncIterable<T>.

private
addEmptyPromiseToQueue(): void

Add an unresolved promise to the end of the queue.

close(error?: Error): Promise<void>
write(item: T): Promise<void>

Usage

import { WritableIterable } from ".";