the light is getting closer

src/util/name_stack.rs

@@ -4,7 +4,7 @@ pub struct NameStack<T>(Vec<HashMap<String, T>>);
 
 impl<T> NameStack<T> {
     pub fn new() -> Self {
-        Self(Vec::new())
+        Self(vec![HashMap::new()])
     }
     pub fn search(&self, name: &str) -> Option<&T> {
         for level in self.0.iter().rev() {
@@ -14,4 +14,10 @@ impl<T> NameStack<T> {
         }
         None
     }
+    pub fn push(&mut self) {
+        self.0.push(HashMap::new());
+    }
+    pub fn pop(&mut self) {
+        self.0.pop();
+    }
 }