Address review comments

parser/src/lexer.rs

@@ -20,8 +20,8 @@ pub enum LexicalError {
 
 #[derive(Clone, Debug, Default, PartialEq)]
 pub struct Location {
-    pub row: usize,
-    pub column: usize,
+    row: usize,
+    column: usize,
 }
 
 impl Location {
@@ -31,6 +31,14 @@ impl Location {
             column: column,
         }
     }
+
+    pub fn get_row(&self) -> usize {
+        self.row
+    }
+
+    pub fn get_column(&self) -> usize {
+        self.column
+    }
 }
 
 pub type Spanned<Tok> = Result<(Location, Tok, Location), LexicalError>;

vm/src/builtins.rs

@@ -223,7 +223,7 @@ fn builtin_isinstance(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
 
 fn builtin_issubclass(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     if args.args.len() != 2 {
-        panic!("isinstance(s) expects exactly two parameters");
+        panic!("issubclass expects exactly two parameters");
     }
 
     let cls1 = args.args[0].clone();

vm/src/vm.rs

@@ -257,7 +257,7 @@ impl VirtualMachine {
                     trace!("Adding to traceback: {:?} {:?}", traceback, lineno);
                     let pos = self.ctx.new_tuple(vec![
                         self.ctx.new_str(filename.clone()),
-                        self.ctx.new_int(lineno.row as i32),
+                        self.ctx.new_int(lineno.get_row() as i32),
                     ]);
                     objlist::append(
                         self,