1 files changed, 16 insertions, 3 deletions
diff --git a/src/eval/scope.rs b/src/eval/scope.rs
index 8f2bd1d5..0991564f 100644
--- a/src/eval/scope.rs
+++ b/src/eval/scope.rs
@@ -21,9 +21,22 @@ pub struct Scopes<'a> {
 }
 
 impl<'a> Scopes<'a> {
-    /// Create a new hierarchy of scopes.
-    pub fn new(base: Option<&'a Scope>) -> Self {
-        Self { top: Scope::new(), scopes: vec![], base }
+    /// Create a new, empty hierarchy of scopes.
+    pub fn new() -> Self {
+        Self {
+            top: Scope::new(),
+            scopes: vec![],
+            base: None,
+        }
+    }
+
+    /// Create a new hierarchy of scopes with a base scope.
+    pub fn with_base(base: &'a Scope) -> Self {
+        Self {
+            top: Scope::new(),
+            scopes: vec![],
+            base: Some(base),
+        }
     }
 
     /// Push a new scope.