fix

Author: aceinetx

zenlang/src/vm/opcodes/vm_call.rs

@@ -11,7 +11,8 @@ impl VM {
                 self.check_stack_overflow();
                 self.pc = addr;
                 self.pc.sub_low(1);
-                self.add_environment();
+
+                self.push_environment();
 
                 let start = self.bfas_stack_start.pop().unwrap();
                 let end = self.bfas_stack_end.pop().unwrap();

zenlang/src/vm/opcodes/vm_ret.rs

@@ -10,7 +10,7 @@ impl VM {
             self.ret = self.stack.pop().unwrap();
         }
 
-        self.remove_environment();
+        self.pop_environment();
 
         if !self.call_stack.is_empty() {
             self.pc = self.call_stack.pop().unwrap();

zenlang/src/vm/vm.rs

@@ -70,17 +70,14 @@ impl VM {
             if func.ctor {
                 self.pc.set_low(func.addr as u32);
                 self.pc.set_high((self.modules.len() - 1) as u32);
-                self.add_environment();
+                self.push_environment();
 
                 while !self.halted {
                     if !self.step() {
                         break;
                     }
                 }
 
-                self.environs
-                    .push(Rc::new(RefCell::new(Environment::new())));
-
                 if !self.error.is_empty() {
                     self.halted = true;
                     return Err(format!(
@@ -131,7 +128,7 @@ impl VM {
                 if function.name == entry_fn_name {
                     self.pc.set_low(function.addr as u32);
                     self.pc.set_high(i as u32);
-                    self.add_environment();
+                    self.push_environment();
                     return Ok(());
                 }
             }
@@ -149,30 +146,44 @@ impl VM {
     }
 
     pub(crate) fn add_environment(&mut self) {
-        let new = Rc::new(RefCell::new(Environment::new()));
-        if let Some(environ) = self.environs.pop() {
-            (&mut *new.borrow_mut()).parent = Some(environ.clone());
+        if self.environs.len() == 0 {
+            panic!("add_environment: environs is empty");
         }
+
+        let new = Rc::new(RefCell::new(Environment::new()));
+        (&mut *new.borrow_mut()).parent = Some(self.environs.pop().unwrap().clone());
         self.environs.push(new);
     }
 
     pub(crate) fn remove_environment(&mut self) {
         if self.environs.len() == 0 {
-            panic!("environs is empty");
+            panic!("remove_environment: environs is empty");
         }
 
         let environ = self.environs.pop().unwrap();
         let environ = &mut *environ.borrow_mut();
 
         if environ.parent.is_none() {
-            self.environs.clear();
+            self.pop_environment();
             return;
         }
 
         self.environs
             .push(core::mem::take(&mut environ.parent).unwrap());
     }
 
+    pub fn push_environment(&mut self) {
+        self.environs
+            .push(Rc::new(RefCell::new(Environment::new())));
+    }
+
+    pub fn pop_environment(&mut self) {
+        if self.environs.len() == 0 {
+            panic!("pop_environment: environs is empty");
+        }
+        self.environs.pop();
+    }
+
     pub fn get_function_name_from_pc(&mut self, pc: u64) -> Option<String> {
         let module_index = pc.get_high() as usize;
         let opcode_index = pc.get_low();