CSV: `Array.from` which a more Unicode friendly form of `split()`.

src/lists.js

@@ -932,7 +932,7 @@ List.prototype.asCSV = function () {
             return string;
         }
         cell = ['\"'];
-        string.split('').forEach(letter => {
+        Array.from(string).forEach(letter => {
             cell.push(letter);
             if (letter === '\"') {
                 cell.push(letter);