September Morn Update

Task/Flatten-a-list/JavaScript/flatten-a-list-6.js

@@ -1,12 +1,5 @@
-function flatten(list) {
-  for (let i = 0; i < list.length; i++) {
-    while (true) {
-      if (Array.isArray(list[i])) {
-      	list.splice(i, 1, ...list[i]);
-      } else {
-      	break;
-      }
-    }
-  }
-  return list;
-}
+// flatten :: Nested List a -> [a]
+const flatten = t => {
+    const go = x => Array.isArray(x) ? x.flatMap(go) : x
+    return go(t);
+};