cqfd

/*
 * To run:
 *   npm install -g babel
 *
 *   babel-node --stage 0 this-script.js
 */

import fs from 'fs'

const mkDir = makePromisey(::fs.mkdir)

cqfd

Yield for sequencing

pogo : *r -> promise[r]

pogo(function*() {
  yield sleep(1000)
  const json = yield $.getJSON('/endpoint')
  return json
 

cqfd

var path = require('path');
var webpack = require('webpack');

var config = module.exports = {
  context: __dirname,
  entry: './index.js',
  output: {
    path: path.join(__dirname, 'build'),
    filename: 'index.js'
  },

cqfd

Idea: programming with a promise for an a as if it were "more or less" an a. That is, we don't want to have to change our programming style too much when transitioning from dealing with actual as to promises for as.

function lift(f) {
  return function(...promises) {
    return Promise.all(promises).then(values => f.apply(null, values))
  }
}

cqfd

{-# OPTIONS_GHC -fwarn-incomplete-patterns #-}
{-# LANGUAGE NoMonomorphismRestriction #-}

module Generators where

import Prelude hiding (take, filter, foldr)

import Control.Applicative
import Control.Monad
import Control.Monad.Trans

cqfd

Generators

function* teammate(name) {
  console.log(`Hi! I'm ${name} and I'm your teammate.`)
  const num = yield "I need a number!"
  const num2 = yield "I need another number!"
  console.log("Ok, here's my work.")
  return num * num2
}

cqfd

'use strict';

/*
 * The trampoline. (Lots of inspiration taken from github.com/tj/co.)
 */

function go(star, ...args) {
  return new Promise((resolve, reject) => {
    const gen = star.apply(null, args);
    gen.resolve = resolve;

cqfd

Let's say we have the following schema:

create_table "users", force: :cascade do |t|
  t.string   "name"
  t.string   "email"
  t.datetime "created_at", null: false
  t.datetime "updated_at", null: false
end

cqfd

var path = require('path');
var webpack = require('webpack');

var config = module.exports = {
  context: __dirname,
  entry: './app/frontend/javascripts/entry.js',
  output: {
    path: path.join(__dirname, 'app', 'assets', 'javascripts'),
    filename: 'bundle.js'
  },

cqfd

const Promise = require('bluebird');
const co = require('co');
const React = require('react');

function* sleep(ms) {
  yield Promise.delay(ms);
}

function usersView(users) {
  const lis = users.map(u => <li>{u.name}</li>);