Added linting, processed current snippets

snippets.js

@@ -0,0 +1,302 @@
+
+const anagrams = str => {
+  if(str.length <= 2)  return str.length === 2 ? [str, str[1] + str[0]] : [str];
+  return str.split('').reduce( (acc, letter, i) =>
+    acc.concat(anagrams(str.slice(0, i) + str.slice(i + 1)).map( val => letter + val )), []);
+}
+// anagrams('abc') -> ['abc','acb','bac','bca','cab','cba']
+
+
+const average = arr =>
+  arr.reduce( (acc , val) => acc + val, 0) / arr.length;
+// average([1,2,3]) -> 2
+
+
+const bottomVisible = _ => 
+  document.documentElement.clientHeight + window.scrollY >= document.documentElement.scrollHeight || document.documentElement.clientHeight;
+// bottomVisible() -> true
+
+
+const capitalizeEveryWord = str => str.replace(/\b[a-z]/g, char => char.toUpperCase());
+// capitalizeEveryWord('hello world!') -> 'Hello World!'
+
+
+const capitalize = (str, lowerRest = false) =>
+  str.slice(0, 1).toUpperCase() + (lowerRest? str.slice(1).toLowerCase() : str.slice(1));
+// capitalize('myName', true) -> 'Myname'
+
+
+const chainAsync = fns => { let curr = 0; const next = () => fns[curr++](next); next(); }
+/*
+chainAsync([
+  next => { console.log('0 seconds'); setTimeout(next, 1000); },
+  next => { console.log('1 second');  setTimeout(next, 1000); },
+  next => { console.log('2 seconds'); }
+])
+*/
+
+
+const palindrome = str =>
+  str.toLowerCase().replace(/[\W_]/g,'').split('').reverse().join('') === str.toLowerCase().replace(/[\W_]/g,'');
+// palindrome('taco cat') -> true
+ 
+
+const chunk = (arr, size) =>
+  Array.apply(null, {length: Math.ceil(arr.length/size)}).map((v, i) => arr.slice(i*size, i*size+size));
+// chunk([1,2,3,4,5], 2) -> [[1,2],[3,4],5]
+
+
+const countOccurrences = (arr, value) => arr.reduce((a, v) => v === value ? a + 1 : a + 0, 0);
+// countOccurrences([1,1,2,1,2,3], 1) -> 3
+
+
+const currentUrl = _ => window.location.href;
+// currentUrl() -> 'https://google.com'
+
+
+const curry = (f, arity = f.length, next) =>
+  (next = prevArgs =>
+    nextArg => {
+      const args = [ ...prevArgs, nextArg ];
+      return args.length >= arity ? f(...args) : next(args);
+    }
+  )([]);
+// curry(Math.pow)(2)(10) -> 1024
+// curry(Math.min, 3)(10)(50)(2) -> 2
+
+
+const deepFlatten = arr =>
+  arr.reduce( (a, v) => a.concat( Array.isArray(v) ? deepFlatten(v) : v ), []);
+// deepFlatten([1,[2],[[3],4],5]) -> [1,2,3,4,5]
+
+
+const difference = (arr, values) => arr.filter(v => !values.includes(v));
+// difference([1,2,3], [1,2]) -> [3]
+
+
+const distance = (x0, y0, x1, y1) => Math.hypot(x1 - x0, y1 - y0);
+// distance(1,1, 2,3) -> 2.23606797749979
+
+
+const isDivisible = (dividend, divisor) => dividend % divisor === 0;
+// isDivisible(6,3) -> true
+
+
+const escapeRegExp = str => str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+// escapeRegExp('(test)') -> \\(test\\)
+
+
+const isEven = num => Math.abs(num) % 2 === 0;
+// isEven(3) -> false
+
+
+const factorial = n => n <= 1 ? 1 : n * factorial(n - 1);
+// factorial(6) -> 720
+
+
+const fibonacci = n => 
+  Array(n).fill(0).reduce((acc, val, i) => acc.concat(i > 1 ? acc[i - 1] + acc[i - 2] : i),[]);
+// fibonacci(5) -> [0,1,1,2,3]
+
+
+const filterNonUnique = arr => arr.filter(i => arr.indexOf(i) === arr.lastIndexOf(i));
+// filterNonUnique([1,2,2,3,4,4,5]) -> [1,3,5]
+
+
+const flatten = arr => arr.reduce( (a, v) => a.concat(v), []);
+// flatten([1,[2],3,4]) -> [1,2,3,4]
+
+
+const arrayMax = arr => Math.max(...arr);
+// arrayMax([10, 1, 5]) -> 10
+
+
+const arrayMin = arr => Math.min(...arr);
+// arrayMin([10, 1, 5]) -> 1
+
+
+const getType = v =>
+  v === undefined ? "undefined" : v === null ? "null" : v.constructor.name.toLowerCase(); 
+// getType(new Set([1,2,3])) -> "set"
+
+
+const getScrollPos = (el = window) =>
+  ( {x: (el.pageXOffset !== undefined) ? el.pageXOffset : el.scrollLeft,
+   y: (el.pageYOffset !== undefined) ? el.pageYOffset : el.scrollTop} );
+// getScrollPos() -> {x: 0, y: 200}
+
+
+const gcd = (x , y) => !y ? x : gcd(y, x % y);
+// gcd (8, 36) -> 4
+
+
+const hammingDistance = (num1, num2) =>
+  ((num1^num2).toString(2).match(/1/g) || '').length;
+// hammingDistance(2,3) -> 1
+
+
+const head = arr => arr[0];
+// head([1,2,3]) -> 1
+
+
+const initial = arr => arr.slice(0,-1);
+// initial([1,2,3]) -> [1,2]
+
+
+const initializeArrayRange = (end, start = 0) =>
+  Array.apply(null, Array(end-start)).map( (v,i) => i + start );
+// initializeArrayRange(5) -> [0,1,2,3,4]
+
+
+const initializeArray = (n, value = 0) => Array(n).fill(value);
+// initializeArray(5, 2) -> [2,2,2,2,2]
+
+
+const last = arr => arr.slice(-1)[0];
+// last([1,2,3]) -> 3
+
+
+const timeTaken = callback => {
+  const t0 = performance.now(), r = callback();
+  console.log(performance.now() - t0);
+  return r;
+}
+// timeTaken(() => Math.pow(2, 10)) -> 1024 (0.010000000009313226 logged in console)
+
+
+const median = arr => {
+  const mid = Math.floor(arr.length / 2), nums = arr.sort((a,b) => a - b);
+  return arr.length % 2 !== 0 ? nums[mid] : (nums[mid - 1] + nums[mid]) / 2;
+}
+// median([5,6,50,1,-5]) -> 5
+// median([0,10,-2,7]) -> 3.5
+
+
+const objectFromPairs = arr => arr.reduce((a,v) => (a[v[0]] = v[1], a), {});
+// objectFromPairs([['a',1],['b',2]]) -> {a: 1, b: 2}
+
+
+const percentile = (arr, val) => 
+  100 * arr.reduce((acc,v) => acc + (v < val ? 1 : 0) + (v === val ? 0.5 : 0), 0) / arr.length;
+// percentile([1,2,3,4,5,6,7,8,9,10], 6) -> 55
+ 
+
+const pipe = (...funcs) => arg => funcs.reduce((acc, func) => func(acc), arg);
+// pipe(btoa, x => x.toUpperCase())("Test") -> "VGVZDA=="
+
+
+const powerset = arr =>
+  arr.reduce( (a,v) => a.concat(a.map( r => [v].concat(r) )), [[]]);
+// powerset([1,2]) -> [[], [1], [2], [2,1]]
+
+
+const promisify = func =>
+  (...args) =>
+    new Promise((resolve, reject) =>
+      func(...args, (err, result) =>
+        err ? reject(err) : resolve(result))
+    );
+// const delay = promisify((d, cb) => setTimeout(cb, d))
+// delay(2000).then(() => console.log('Hi!')) -> Promise resolves after 2s
+
+
+const randomIntegerInRange = (min, max) => Math.floor(Math.random() * (max - min + 1)) + min;
+// randomIntegerInRange(0, 5) -> 2
+
+
+const randomInRange = (min, max) => Math.random() * (max - min) + min;
+// randomInRange(2,10) -> 6.0211363285087005
+
+
+const randomizeOrder = arr => arr.sort( (a,b) => Math.random() >= 0.5 ? -1 : 1);
+// randomizeOrder([1,2,3]) -> [1,3,2]
+
+
+const redirect = (url, asLink = true) =>
+  asLink ? window.location.href = url : window.location.replace(url);
+// redirect('https://google.com')
+
+
+const reverseString = str => [...str].reverse().join('');
+// reverseString('foobar') -> 'raboof'
+
+
+const rgbToHex = (r, g, b) => ((r << 16) + (g << 8) + b).toString(16).padStart(6, '0');
+// rgbToHex(255, 165, 1) -> 'ffa501'
+
+
+const series = ps => ps.reduce((p, next) => p.then(next), Promise.resolve());
+// const delay = (d) => new Promise(r => setTimeout(r, d))
+// series([() => delay(1000), () => delay(2000)]) -> executes each promise sequentially, taking a total of 3 seconds to complete
+
+
+const scrollToTop = _ => {
+  const c = document.documentElement.scrollTop || document.body.scrollTop;
+  if(c > 0) {
+    window.requestAnimationFrame(scrollToTop);
+    window.scrollTo(0, c - c/8);
+  }
+}
+// scrollToTop()
+
+
+const shuffle = arr => {
+  let r = arr.map(Math.random);
+  return arr.sort((a,b) => r[a] - r[b]);
+}
+// shuffle([1,2,3]) -> [2, 1, 3]
+
+
+const similarity = (arr, values) => arr.filter(v => values.includes(v));
+// similarity([1,2,3], [1,2,4]) -> [1,2]
+
+
+const sortCharactersInString = str =>
+  str.split('').sort( (a,b) => a.localeCompare(b) ).join('');
+// sortCharactersInString('cabbage') -> 'aabbceg'
+
+
+const sum = arr => arr.reduce( (acc , val) => acc + val, 0);
+// sum([1,2,3,4]) -> 10
+
+
+[varA, varB] = [varB, varA];
+// [x, y] = [y, x]
+
+
+const tail = arr => arr.length > 1 ? arr.slice(1) : arr;
+// tail([1,2,3]) -> [2,3]
+// tail([1]) -> [1]
+
+
+const truncate = (str, num) =>
+  str.length > num ? str.slice(0, num > 3 ? num-3 : num) + '...' : str;
+// truncate('boomerang', 7) -> 'boom...'
+
+
+const unique = arr => [...new Set(arr)];
+// unique([1,2,2,3,4,4,5]) -> [1,2,3,4,5]
+
+
+const getUrlParameters = url =>
+  url.match(/([^?=&]+)(=([^&]*))?/g).reduce(
+    (a,v) => (a[v.slice(0,v.indexOf('='))] = v.slice(v.indexOf('=')+1), a), {}
+  );
+// getUrlParameters('http://url.com/page?name=Adam&surname=Smith') -> {name: 'Adam', surname: 'Smith'}
+
+
+const uuid = _ =>
+  ( [1e7]+-1e3+-4e3+-8e3+-1e11 ).replace( /[018]/g, c =>
+    (c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16)
+  );
+// uuid() -> '7982fcfe-5721-4632-bede-6000885be57d'
+
+
+const validateNumber = n => !isNaN(parseFloat(n)) && isFinite(n);
+// validateNumber('10') -> true
+
+
+const valueOrDefault = (value, d) => value || d;
+// valueOrDefault(NaN, 30) -> 30
+
+