Add regular expression statement, make sure rust functions work

examples/test.lua

@@ -5,5 +5,5 @@ function add(x)
     end
 end
 
-pr = print(add(10)(15))
-pr = print(add(10)(15))
+print(max(11, 9))
+print(add(10)(15))

src/ast.rs

@@ -209,6 +209,7 @@ pub enum Statement {
     Assignment(Option<AccessModifier>, Vec<Node<String>>, ExpressionList),
     Return(ExpressionList),
     If(Node<Expression>, Block),
+    Expression(Node<Expression>),
 }
 
 impl Parse for Statement {
@@ -266,6 +267,8 @@ impl Parse for Statement {
                 vec![name],
                 ExpressionList(vec![stream.parse()?]),
             ))
+        } else if let Ok(expr) = stream.parse() {
+            Ok(Self::Expression(expr))
         } else {
             Err(stream.expecting_err("statement"))
         }

src/compile.rs

@@ -103,6 +103,7 @@ impl Statement {
                 constants.extend(then.find_constants(scope));
                 constants
             }
+            Statement::Expression(expr) => expr.kind.find_constants(scope),
         }
     }
 
@@ -224,6 +225,10 @@ impl Statement {
                 ));
             }
             Statement::If(node, block) => todo!(),
+            Statement::Expression(expr) => {
+                let (instr, _) = expr.kind.compile(state, scope, None);
+                instructions.extend(instr);
+            }
         }
 
         instructions

src/vm.rs

@@ -291,11 +291,18 @@ impl ClosureRunner {
                     match value {
                         Value::RustFunction(func) => {
                             let ret_values = func.borrow_mut().execute(params);
-                            for i in 0..=(*ret_len - 2) {
-                                self.stack.insert(
-                                    *func_reg + i,
-                                    ret_values.get(i as usize).cloned().unwrap_or(Value::Nil),
-                                );
+                            if *ret_len != 0 {
+                                for i in 0..=(*ret_len - 2) {
+                                    self.stack.insert(
+                                        *func_reg + i,
+                                        ret_values.get(i as usize).cloned().unwrap_or(Value::Nil),
+                                    );
+                                }
+                            } else {
+                                for (i, value) in ret_values.iter().enumerate() {
+                                    self.stack.insert(*func_reg + i as u16 + 1, value.clone());
+                                }
+                                self.top = *func_reg + ret_values.len() as u16;
                             }
                         }
                         Value::Function(closure) => {