event_listener.js

const $input = document.getElementById('input');
let INPUT_DEBOUNCE = null;

$input.addEventListener('input', e => {
    clearTimeout(INPUT_DEBOUNCE);
    $span.textContent = ''; // let's come to this on a later stage, for now pretend it doesn't exist
  
    INPUT_DEBOUNCE = setTimeout(() => main(e), 250);
});