big-brain.js

Ranges

  import { range } from 'big-brain.js';

  /**
    * Can be used to make loops
    */
  for (let i of range(3)) {
    console.log(`hello from loop ${i}`);
  }
  // hello from loop 0
  // hello from loop 1
  // hello from loop 2

  /**
    * Ranges to Arrays
    */
  Array.from(range(12));
  // [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]

  Array.from(range(11, 18));
  // [ 11, 12, 13, 14, 15, 16, 17 ]

  Array.from(range(10, 0));
  // [ 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 ]

  /**
    * Unlike Python ranges, step is always a positive number
    */
  Array.from(range(0, 20, 2));
  // [0,  2,  4,  6,  8, 10, 12, 14, 16, 18]
            

Random Integers

(without having to write the function yourself each time (I always forget how it goes :c))

  import { randInt } from 'big-brain.js';

  randInt(100);
  // 40

  randInt(1, 5);
  // 3

  /**
    * Random enough for general purpose
    */
  let ints = [];
  for (let i of range(10000000)) {
    ints.push(randInt(1, 11));
  }

  /**
    * Should be 5.5
    */
  ints.reduce((previous, current) => current += previous) / ints.length;
  // 5.5007626
            

Random choice from array

  import { randChoice } from 'big-brain.js';

  const presidents = ['George Washington', 'John Adams', 'Thomas Jefferson', 'James Madison', 'James Monroe'];

  randChoice(presidents);
  // 'John Adams'
            

Shuffle arrays

(this doesn't mutate the array)

  import { shuffleArray } from 'big-brain.js';

  let presidents = ['George Washington', 'John Adams', 'Thomas Jefferson', 'James Madison', 'James Monroe'];

  shuffleArray(presidents);
  // ['James Monroe', 'George Washington', 'James Madison', 'John Adams', 'Thomas Jefferson']

  /**
    * Note that the original array is still in order
    */
  presidents
  // ['George Washington', 'John Adams', 'Thomas Jefferson', 'James Madison', 'James Monroe']

  /**
    * To permanently rearrange, reassign:
    */
  presidents = shuffleArray(presidents);
  // ['James Monroe', 'Thomas Jefferson', 'George Washington', 'John Adams', 'James Madison']
            

Extract from Iterables

  import { first, second, last, rest } from 'big-brain.js';

  const natoPhoneticAlphabet = ['alpha', 'bravo', 'charlie', 'delta']

  first(natoPhoneticAlphabet);
  // 'alpha'

  second(natoPhoneticAlphabet);
  // 'bravo'

  last(natoPhoneticAlphabet);
  // 'delta'

  rest(natoPhoneticAlphabet); 
  // ['bravo', 'charlie', 'delta']