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# See
def meth a, b, c
[yield(a), yield(b), yield(c)]
meth(1, 2, 3) { |x| x * x }
# => [1, 4, 9]
arr = [1962, 6, 14, lambda { |x| x.to_s }]
let Person = (() = > {
let firstNameProperty = Symbol('firstName'),
lastNameProperty = Symbol('lastName'),
renameMethod = Symbol('rename');
return class Person {
constructor (first, last) {
this[renameMethod](first, last);
fullName () {

Reading JavaScript Allongé on Kindle

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const SecretDecoderRing = {
encode: function (plaintext) {
return plaintext
.map( char => char.charCodeAt() )
.map( code => code + 1 )
.map( code => String.fromCharCode(code) )
decode: function (cyphertext) {

Because combinators like this:

var __slice = Array.prototype.slice;

function invoke (fn) {
  var args =, 1);

  return function (instance) {
    return fn.apply(instance, args)

(from Hilbert's Grand JavaScript School)

day six

Bertie goes home, exhausted, and dreams that having graduated everyone at the end of Day Five, things are busier than ever. In his dreams he imagines an infinite number of galactic superclusters, each containing an infinite number of galaxies, each containing an infinite number of stars, each containing an infinite number of worlds, each containing an infinite number of oceans, each containing an infinite number of aircraft carriers, each containing an infinite number of buses, each containing an infinite number of students.

He awakens and reasons that what he is dealing with are powers of infinity. A simple infinity is infinity to the first power. Two infinities (buses and students) is infinity to the second power. Three infinities (aircraft carriers, buses, and students) is infinity to the third power. And so forth up to galactic superclusters, infinity to the eighth power.

something = if condition

In JavaScript, you can make a right-variadic function by gathering parameters. For example:

const abccc = (a, b, ...c) => {

abccc(1, 2, 3, 4, 5)
const div = (verbed, numerator, denominator) =>
`${numerator} ${verbed} ${denominator} is ${numerator/denominator}`
div('divided by', 1, 3)
//=> 1 divided by 3 is 0.3333333333333333
const anyPartialApplication = (() => {
const placeholder = {},
anyPartialApplication = (fn, ...template) => {
let remainingArgIndex = 0;
const sorted = arr => {
const length = arr.length;
let unsorted = new Array(length),
sorted = new Array(length);
const destructiveSort = (unsorted, sorted, offset, length) => {
if (length === 1) {
sorted[offset] = unsorted[offset];
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