First commit

exercises/ch01/ex01/main.lua

@@ -0,0 +1,14 @@
+-- Negative n resulted in a stackoverflow (infinite recursion)
+function fact(n)
+    if n == 0 then
+        return 1
+    elseif n < 0 then
+        return nil
+    else
+        return n * fact(n - 1)
+    end
+end
+
+print("enter a number:")
+a = io.read("*n")
+print(fact(a))