jonurry

function runRobot(state, robot, memory) {
  for (let turn = 0;; turn++) {
    if (state.parcels.length == 0) {
      return turn;
    }
    let action = robot(state, memory);
    state = state.move(action.direction);
    memory = action.memory;
  }
}

jonurry

let map = {one: true, two: true, hasOwnProperty: true};
// Fix this call
//console.log(map.hasOwnProperty("one"));
console.log(hasOwnProperty.call(map, 'one'));
// → true

jonurry

class Group {
  constructor() {
    this.group = [];
  }
  add(item) {
    if (!this.group.includes(item)) {
      this.group.push(item);
    }
  }
  delete(item) {

jonurry

class Group {
  constructor() {
    this.group = [];
  }
  add(item) {
    if (!this.group.includes(item)) {
      this.group.push(item);
    }
  }
  delete(item) {

jonurry

class Vec {
  constructor (x, y) {
    this.x = x;
    this.y = y;
  }
  plus(v) {
    return new Vec(this.x + v.x, this.y + v.y);
  }
  minus(v) {
    return new Vec(this.x - v.x, this.y - v.y);

jonurry

// 5.4 Dominant Writing Direction

function characterScript(code) {
  for (let script of SCRIPTS) {
    if (script.ranges.some(([from, to]) => code >= from &&
                                           code < to)) {
      return script;
    }
  }
  return null;

jonurry

// 5.3 Everything
//every using a loop
function every(array, test) {
  for (let element of array) {
    if (test(element) === false) {
      return false;
    }
  }
  return true;
}

jonurry

// 5.2 looping version
function loop(value, test, update, body) {
  for (let i = value; test(i); i = update(i)) {
    body(i)
  }
}

loop(3, n => n > 0, n => n - 1, console.log);
// → 3
// → 2

jonurry

// 5.1 Flattening
let arrays = [[1, 2, 3], [4, 5], [6]];
console.log(arrays.reduce((array1, array2) => array1.concat(array2)));
// → [1, 2, 3, 4, 5, 6]

jonurry

function deepEqual(a, b) {
  if (a === b) {
    // items are identical
    return true;
  } else if (typeof a === 'object' && a !== null && typeof b === 'object' && b !== null) {
  	// items are objects - do a deep property value compare
    // join keys from both objects together in one array
    let keys = Object.keys(a).concat(Object.keys(b));
    // filter out duplicate keys
    keys = keys.filter(