@tommymynnson/lotide/letterPositions.js

A mini clone of the [Lodash](https://lodash.com) library.

const letterPositions = (sentence) => {
  const results = {};

  for (let i = 0; i < sentence.length; i++) {
    if (results[sentence[i]]) {
      results[sentence[i]].push(i);
    } else {
      if (sentence[i] !== ' ') {
        results[sentence[i]] = [i];
      }
    }
  }

  return results;
};

module.exports = letterPositions;