recursion!

src/main.ts

@@ -31,3 +31,9 @@ e('"abc" & "def"');
 e('n = 5; n | 5 \\ "five" | _ \\ "other"');
 e('list = [1, 2, 3]; list | [x, y, z] \\ x + y + z');
 e('point = {x = 5, y = 10}; point | {x = px, y = py} \\ px + py');
+
+e(`factorial = n \\ n
+  | 0 \\ 1
+  | n \\ n * factorial (n - 1);
+
+  factorial 5`)