re-implement lambdas

src/executor.rs

@@ -352,7 +352,7 @@ where
                     Ok(Value::Nil)
                 }
             }
-            ParseTree::LambdaDefinition(func) => todo!(),
+            ParseTree::LambdaDefinition(func) => Ok(Value::Function(func)),
         }
     }
 }

src/tokenizer.rs

@@ -413,7 +413,7 @@ mod tests {
 
     #[test]
     fn uwu() {
-        let program = ":. add x y + x y";
+        let program = ": id ?. x Any -> Any x id 5";
 
         let tokens: Vec<Token> = Tokenizer::from_str(program).unwrap().collect::<Result<_, TokenizeError>>().unwrap();