kefir/src/many-sources/merge.js

Reactive Programming library for JavaScript inspired by Bacon.js and RxJS with focus on high performance and low memory usage

import {inherit} from '../utils/objects'
import AbstractPool from './abstract-pool'
import never from '../primary/never'

function Merge(sources) {
  AbstractPool.call(this)
  this._addAll(sources)
  this._initialised = true
}

inherit(Merge, AbstractPool, {
  _name: 'merge',

  _onEmpty() {
    if (this._initialised) {
      this._emitEnd()
    }
  },
})

export default function merge(observables) {
  return observables.length === 0 ? never() : new Merge(observables)
}