kefir/src/time-based/sequentially.js

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

import timeBased from '../patterns/time-based'
import {cloneArray} from '../utils/collections'
import never from '../primary/never'

const S = timeBased({
  _name: 'sequentially',

  _init({xs}) {
    this._xs = cloneArray(xs)
  },

  _free() {
    this._xs = null
  },

  _onTick() {
    if (this._xs.length === 1) {
      this._emitValue(this._xs[0])
      this._emitEnd()
    } else {
      this._emitValue(this._xs.shift())
    }
  },
})

export default function sequentially(wait, xs) {
  return xs.length === 0 ? never() : new S(wait, {xs})
}