kylehovey

const M = f => f(f);

const Y = fn => M(
  maker => x => fn(maker(maker))(x)
);

const YY = fn => {
  const cache = new Map;

  return M(

kylehovey

const mkWrapper = () => (
  cache => f => n => n in cache
    ? cache[n]
    : cache[n] = f(n)
)([]);
const M = f => f(f);
const Y = f => (
  wrapper => M(
    maker => n => wrapper(
      f(M(maker))

kylehovey

const fact = n => n <= 0 ? 1 : n * fact(n-1);
const choose = (n, k) => fact(n) / (fact(n - k) * fact(k));
const mapper = predicate => n => predicate(n) ? 1 : 0;
const [isEven, isOdd] = [0,1].map(k => mapper(n => n % 2 === k));
const iverson = k => mapper(n => n === k);
const coverNegative = f => n => n < 0 ? 0 : f(n);
const conjugatePair = (a, b) => [a+b, a-b];
const round = fn => n => Math.round(fn(n));
const range = n => Array(n).fill().map((_, i) => i);
const reversed = xs => [...xs].reverse();

kylehovey

#include <functional>
#include <vector>
#include <iostream>

namespace Observable {
  template <typename D>
  using Callback = std::function<void(const D&)>;

  template <typename D, typename R>
  using Morphism = std::function<R(D)>;

kylehovey

const mapper = predicate => n => predicate(n) ? 1 : 0;
const [isEven, isOdd] = [0,1].map(k => mapper(n => n % 2 === k));
const iverson = k => mapper(n => n === k);
const range = n => Array(n).fill().map((_, i) => i);
const coverNegative = f => n => n < 0 ? 0 : f(n);
const conjugatePair = (a, b) => [a+b, a-b];

const a = coverNegative(
  n => 4*b(n-1) + 2*a(n-1) + a(n-2) + iverson(0)(n)
);

kylehovey

function *_range(from, to) {
  if (to === undefined) {
    yield *_range(0, from);
    return;
  }

  yield [ from ];

  if (from >= to) return;

kylehovey

/**
 * Creates an intermediate value that can be resolved later.
 * @return {Object} Eventual
 * @return {Function} Eventual.then Acts like Promise.then for the eventual value
 * @return {Function} Eventual.resolve Acts like Promise.resolve for the eventual
 * @return {Function} Eventual.reject Acts like Promise.reject for the eventual
 */
const eventual = () => (
  _eventual => ({
    /**

kylehovey

function memoize(f) {
  const cache = new Map;

  return (...args) => {
    const key = JSON.stringify(...args);

    if (!cache.has(key)) {
      cache.set(key, f(...args));
    }