Add clone and reach helpers.

reach.js

@@ -0,0 +1,11 @@
+export const reach = (path, data) => {
+  const parts = path.split('.');
+  let part;
+  while (part = parts.shift()) {
+    data = data instanceof Set || data instanceof Map ? data.get(part) : data[part];
+    if (parts.length > 0 && (typeof data !== 'object' || data === null)) {
+      return;
+    }
+  }
+  return data;
+}