Function negation

ablescript/src/variables.rs

@@ -443,7 +443,27 @@ impl ops::Not for Value {
                 Abool::Sometimes => Abool::Sometimes,
                 Abool::Always => Abool::Never,
             }),
-            Value::Functio(_) => todo!(),
+            Value::Functio(f) => Value::Functio(match f {
+                Functio::BfFunctio {
+                    mut instructions,
+                    tape_len,
+                } => {
+                    instructions.reverse();
+                    Functio::BfFunctio {
+                        instructions,
+                        tape_len,
+                    }
+                }
+                Functio::AbleFunctio {
+                    mut params,
+                    mut body,
+                } => {
+                    params.reverse();
+                    body.reverse();
+                    Functio::AbleFunctio { params, body }
+                }
+                Functio::Eval(code) => Functio::Eval(code.chars().rev().collect()),
+            }),
             Value::Cart(c) => Value::Cart(
                 c.into_iter()
                     .map(|(k, v)| (v.borrow().clone(), Rc::new(RefCell::new(k))))