A DESCRIPTION OF THE PROBLEM :
Code such as

        public static void main(String args[]) {
                Object o = new Object();
                Object os = (Supplier<Object>) switch(o) {
                        case Object r -> (Supplier<Object>)() -> r;
                };
        }

runs without issue, whereas

        public static void main(String args[]) {
                Object o = new Object();
                Object os = (Supplier<Object>) switch(o) {
                        case Object r -> () -> r;
                };
        }

gives

error: lambda expression not expected here
                        case Object r -> () -> r;
                                                  ^