num to word

numToWords.ts

function arr(x: any) {
  return Array.from(x);
}
function num(x: any) {
  return Number(x) || 0;
}
function str(x: any) {
  return String(x);
}
function isEmpty(xs: any) {
  return xs.length === 0;
}
function take(n: any) {
  return (xs: any) => xs.slice(0, n);
}
function drop(n: any) {
  return (xs: any) => xs.slice(n);
}
function reverse(xs: any) {
  return xs.slice(0).reverse();
}
function comp(f: any) {
  return function(g: any) {
    return function(x: any) {
      return f(g(x));
    };
  };
}
function not(x: any) {
  return !x;
}
function chunk(n: any) {
  return (xs: any): any =>
    isEmpty(xs) ? [] : [take(n)(xs), ...chunk(n)(drop(n)(xs))];
}

function numToWords(n: any): any {
  let a = [
    '',
    'one',
    'two',
    'three',
    'four',
    'five',
    'six',
    'seven',
    'eight',
    'nine',
    'ten',
    'eleven',
    'twelve',
    'thirteen',
    'fourteen',
    'fifteen',
    'sixteen',
    'seventeen',
    'eighteen',
    'nineteen'
  ];
  let b = [
    '',
    '',
    'twenty',
    'thirty',
    'forty',
    'fifty',
    'sixty',
    'seventy',
    'eighty',
    'ninety'
  ];
  let g = [
    '',
    'thousand',
    'million',
    'billion',
    'trillion',
    'quadrillion',
    'quintillion',
    'sextillion',
    'septillion',
    'octillion',
    'nonillion'
  ];
  function makeGroup([ones, tens, huns]: any[]) {
    return [
      num(huns) === 0 ? '' : a[huns] + ' hundred ',
      num(ones) === 0 ? b[tens] : (b[tens] && b[tens] + '-') || '',
      a[tens + ones] || a[ones]
    ].join('');
  }
  function thousand(group: any, i: any) {
    return group === '' ? group : `${group} ${g[i]}`;
  }
  if (typeof n === 'number') return numToWords(String(n));
  else if (n === '0') return 'zero';
  else
    return comp(chunk(3))(reverse)(arr(n)) // what the fuck?
      .map(makeGroup)
      .map(thousand)
      .filter(comp(not)(isEmpty))
      .reverse()
      .join(', ');
}