Merge branch 'namespace' of https://github.com/schungx/rhai into namespace

src/engine.rs

@@ -1188,7 +1188,8 @@ impl Engine {
                         Some((index, ScopeEntryType::Normal)) => {
                             *scope.get_mut(index).0 = rhs_val;
                             Ok(Default::default())
-                        }
+                        },
+                        Some((_, ScopeEntryType::Subscope)) => unreachable!(),
                     },
                     // idx_lhs[idx_expr] = rhs
                     #[cfg(not(feature = "no_index"))]
@@ -1497,6 +1498,11 @@ impl Engine {
                 Ok(Default::default())
             }
 
+            // Import statement
+            Stmt::Import(_name_expr, _alias) => {
+                unimplemented!()
+            }
+
             // Const statement
             Stmt::Const(name, expr, _) if expr.is_constant() => {
                 let val = self.eval_expr(scope, state, fn_lib, expr, level)?;