iter-tools-es/impls/$forkerate/async-forkerate.js

The iterable toolbox

const {
  asyncEnsureIterable
} = require('../../internal/async-iterable.js');

const {
  AsyncExchange
} = require('../../internal/async-fork.js');

const {
  AsyncPeekerator
} = require('../../internal/async-peekerator.js');

const _ = Symbol.for('_');

class AsyncForkerator extends AsyncPeekerator {
  static async from(source) {
    const exchange = new AsyncExchange(asyncEnsureIterable(source)[Symbol.asyncIterator]());
    return await super.from(exchange.fork(), exchange);
  }

  constructor(iterator, first, exchange) {
    super(iterator, first);
    this[_].exchange = exchange;
  }

  async advance(n = 1) {
    for (let i = 0; i < n; i++) {
      await super.advance();

      this[_].exchange.advance();
    }

    return this;
  }

  fork() {
    return this[_].exchange.fork();
  }

  [Symbol.asyncIterator]() {
    return this[_].exchange.fork();
  }

}

function __asyncForkerate(source) {
  return AsyncForkerator.from(source);
}

exports.__asyncForkerate = __asyncForkerate;

function asyncWrapWithEnsureIterable(fn) {
  return source => fn(asyncEnsureIterable(source));
}

const asyncForkerate = asyncWrapWithEnsureIterable(__asyncForkerate);
exports.asyncForkerate = asyncForkerate;