jooyunghan

function even(n) {
  if (n === 0) return true;
  else return odd(n-1);
}
function odd(n) {
  if (n === 0) return false;
  else return even(n-1);
}
console.log(even(100000));

jooyunghan

const FAIL = {};
let _pos;
let _input;

function parse(input) {
  _input = input;
  _pos = 0;
  const r = parens();
  if (r === FAIL || _pos !== _input.length) throw new Error('parse error');
  return r;

jooyunghan

// parser = string -> [match, remainder]

// read single item
function* item(s) {
  if (s.length > 0) yield [s[0], s.slice(1)];
}

function run(p, s) {
  return [...p(s)]
}

jooyunghan

const letters = c => ({
  0: " ",
  1: "",
  2: "abc",
  3: "def",
  4: "ghi",
  5: "jkl",
  6: "mno",
  7: "pqrs",
  8: "tuv",

jooyunghan

const flatMap = (f, as) => {
  const result = [];
  for (const a of as) {
    result.push(...f(a));
  }
  return result;
}

const map = (f, as) => {
  const result = [];

jooyunghan

const traverse = (f, as) => sequence(map(f, as));

const sequence = (as) => {
  if (as.length === 0) return [""];
  return flatMap(a => map(b => [a, ...b], sequence(as.slice(1))), as[0])
}

jooyunghan

var letterCombinations = function(digits) {
  if (digits.length === 0) return [];

  const result = [''];
  const letters = ' ||abc|def|ghi|jkl|mno|pqrs|tuv|wxyz'.split('|');
  for (const d of digits) {
    for (const r of result.splice(0)) {
      for (const l of letters[+d]) {
        result.push(r + l);
      }

jooyunghan

function createAsyncIterator() {
  const self = this;
  return ag(function*() {
    const resume = [];
    const values = [];

    const subscription = self.materialize().subscribe(value => {
      values.push(value);
      resume.splice(0).forEach(r => r());
    });

jooyunghan

export function ag(f) {
  const promises = [];
  const g = f();
  return {
    [Symbol.asyncIterator]() {
      return this;
    },
    next(input) {
      if (promises.length > 0) {
        return new Promise((resolve, reject) => {

jooyunghan

async function* createAsyncIterator() {
  const promise = [];
  const values = [];

  const subscription = this.materialize().subscribe(value => {
    values.push(value);
    promise.splice(0).forEach(r => r());
  });

  try {