lubien

const
  composeN = (...fs) => x =>
    fs.reduceRight((x, f) => f(x), x)
  
, map = f => xs =>
    xs.map(f)

, reduce = f => xs =>
    xs.reduce(f)
    

lubien

/**
* Show Me the Evens - Show me the Odds 
* Diana is learning to count and she just learned the difference between odds and even numbers. 
* She wants to have some fun, so she picks a random number. 
* If that number is even, she decides to count all the even numbers up to it starting from 0 up to (but not including) the input. 
* If not, she decides to count all the odd numbers up to that number starting from 1 (but not including) the input. 
**/

const
  range = x => y =>

lubien

/**
* Show Me the Evens - Show me the Odds 
* Diana is learning to count and she just learned the difference between odds and even numbers. 
* She wants to have some fun, so she picks a random number. 
* If that number is even, she decides to count all the even numbers up to it starting from 0 up to (but not including) the input. 
* If not, she decides to count all the odd numbers up to that number starting from 1 (but not including) the input. 
**/

function counting(x){
  return [...Array(x).keys()]

lubien

const
  range = x => y =>
    Array.from({length: y - x})
      .map((_, i) => x + i)
      
, {ceil, sqrt} = Math

, lt = y => x =>
    x < y
    

lubien

const clamp = l => h => x =>
  x > h
    ? h
    : x < l
      ? l
      : x

const
  ascend = i => xs => {
    let

lubien

const
  composeN = (...fs) => y =>
    fs.reduceRight((x, f) => f(x), y)

, flatten = xs =>
    xs.reduce((acc, x) => acc.concat(x))
    
, filter = pred => xs =>
    xs.filter(pred)
    

lubien

const
 composeN = (...fs) => y =>
    fs.reduceRight((x, f) => f(x), y)
  
, concat = ys => xs =>
    xs.concat(ys)

, flatten = xs =>
    reduce(uncurry2(concat))(xs)

lubien

const
  id = x =>
    x

, always = x => () =>
    x

, not = prop =>
    !prop
    

lubien

Sum a dimension N square matrix main and anti diagonal values.

Given the Matrix:

[ [ 1,  2,  3,  4]
, [ 5,  6,  7,  8]
, [ 9, 10, 11, 12]
, [13, 14, 15, 16]
]

lubien

1. Think in a two-digit number.
2. Subtract by it's digits sum. Ex.: 13 - (1 + 3).
3. Sum it's digits. Ex.: 13 => 1 + 3.
4. Sum by 4.
5. Multiply by it's reversed digits number. Ex.: 31 * 13.
6. Multiply by 3.
7. Should be equal 1209.