blazecolour

function LinkedListToArr(list) {
    var result = [list.value],
        obj = list;
    while (obj.next) {
        result.push(obj.next.value)
        obj = obj.next;
    }
    return result.join(', ');
}

blazecolour

let instance = null;

class Cashe {
  constructor() {
    if (!instance) {
      instance = this;
    }
    this.time = new Date();
    return instance;
  }

blazecolour

const arr = [10, 12, 15, 21];

for (var i = 0; i < arr.length; i++) {
  setTimeout(function() {
    console.log("Index: " + i + ", element: " + arr[i]);
  }, 3000);
}

// -> Index: 4, element: undefined(printed 4 times)

blazecolour

// type 𝔹 := ∀ α, α → α → α

// T : 𝔹
const T = a => b => a;

// F : 𝔹
const F = a => b => b;

// iff : ∀ α, 𝔹 → α → α → α
const iff = c => a => b => c(a)(b);

blazecolour

const average = (...arg) =>
  arg.reduce((total, amount, index) => {
    total += amount;
    return index === arg.length - 1 ? total / arg.length : total;
  });

blazecolour

const count = arr => arr.reduce((acc, item) => 
  ({ ...acc, [item]: acc[item] ? acc[item] + 1 : 1 }), {});

// const count = arr =>
//  arr.reduce((acc, item) => ({ ...acc, [item]: (acc[item] || 0) + 1 }), {});

blazecolour

const flatten = arr =>
  Array.isArray(arr)
    ? arr.reduce((done, curr) => done.concat(flatten(curr)), [])
    : arr;

blazecolour

const clone = x => [...x];

const push = x => y => [...x, y];

const pop = x => x.slice(0, -1);

const unshift = y => x => [y, ...x];

const shift = x => x.slice(1);

blazecolour

const map = (fn, arr) =>
  arr.reduce((acc, item, index, arr) => {
    return acc.concat(fn(item, index, arr));
  }, []);

blazecolour

const filter = (fn, arr) =>
  arr.reduce((newArr, item) => {
    return fn(item) ? newArr.concat([item]) : newArr;
  }, []);