Functional Stuffs 1

functional_stuffs.js

const input = document.getElementById('input');
const outPut = document.getElementById('output');

const leftKeys = [
  'q', 'w', 'e', 'r', 't',
  'a', 's', 'd', 'f', 'g',
  'z', 'x', 'c', 'v',
];

const rightKeys = [
  'y', 'u', 'i', 'o', 'p',
  'h', 'j', 'k', 'l', 'ç',
  'b', 'n', 'm',
];

const pipe = function(first, ...others) {
  return function() {
    return others.reduce((acc, fn) => {
      return fn.call(null, acc);
    }, first.apply(null, arguments));
  }
}

const curry = function(fn) {
  const partial = function(prevArgs = []) {
    return function() {
      const nextArgs = [...prevArgs, ...arguments];
      if((prevArgs.length + arguments.length) === fn.length) {
        return fn.apply(null, nextArgs)
      } else {
        return partial(nextArgs);
      }
    }
  }
  return partial();
};

const removeSpaces = w => w.replace(/\s/g, '');
const toLower = w => w.toLowerCase();
const toArray = w => w.split('');
const numWords = curry((l, w) => w.filter(k => l.includes(k)).length);


const getKeysDistribution = (word) => ({
  left: pipe(removeSpaces, toLower, toArray, numWords(leftKeys))(word),
  right: pipe(removeSpaces, toLower, toArray, numWords(rightKeys))(word),
});

input.addEventListener('input', (event) => {
  outPut.value = JSON.stringify(
    getKeysDistribution(input.value)
  );
});