const binomialCoefficient = (n, k) => {
  if (Number.isNaN(n) || Number.isNaN(k)) return NaN;
  if (k < 0 || k > n) return 0;
  if (k === 0 || k === n) return 1;
  if (k === 1 || k === n - 1) return n;
  if (n - k < k) k = n - k;
  let res = n;
  for (let j = 2; j <= k; j++) res *= (n - j + 1) / j;
  return Math.round(res);
};

binomialCoefficient(8, 2); // 28

const getURLParameters = url =>
(url.match(/([^?=&]+)(=([^&]*))/g) || []).reduce(
    (a, v) => (
      (a[v.slice(0, v.indexOf('='))] = v.slice(v.indexOf('=') + 1)), a
    ),
    {}
);

const head = arr => (arr && arr.length ? arr[0] : undefined);

head([1, 2, 3]); // 1
head([]); // undefined
head(null); // undefined
head(undefined); // undefined

//use this with canvas file finder
function NewTab(testing) {
  window.open(testing, "_blank");
}

for(test in results) {
  var testing = 'https://unt.instructure.com/files/' + test + '/download';
  NewTab(testing);
}

// `arr` is an array
const clone = arr => arr.slice(0);

// Or
const clone = arr => [...arr];

// Or
const clone = arr => Array.from(arr);

// Or
const clone = arr => arr.map(x => x);

// Or
const clone = arr => JSON.parse(JSON.stringify(arr));

// Or
const clone = arr => arr.concat([]);

const dragAndDropDiv = editor.container;

dragAndDropDiv.addEventListener('dragover', function(e) {
    e.stopPropagation();
    e.preventDefault();
    e.dataTransfer.dropEffect = 'copy';
});
dragAndDropDiv.addEventListener("drop",function(e){
    // Prevent default behavior (Prevent file from being opened)
    e.stopPropagation();
    e.preventDefault();
    const files = e.dataTransfer.items; // Array of all files

    console.assert(files.length >= 1);

    if (files[0].kind === 'file') {
        var file = e.dataTransfer.items[0].getAsFile();
        const fileSize = file.size;
        const fileName = file.name;
        const fileMimeType = file.type;

        reader = new FileReader();

        reader.onloadend = function(){
            editor.setValue(reader.result);
        }

        reader.readAsText(file);
    }else{
        //Maybe handle if text is dropped
        console.log(files[0].kind);
    }
});