Add `in` and `not in` operators

1 files changed, 5 insertions, 0 deletions

diff --git a/src/eval/dict.rs b/src/eval/dict.rs
index 03871fa0..9127b2eb 100644
--- a/src/eval/dict.rs
+++ b/src/eval/dict.rs
@@ -61,6 +61,11 @@ impl Dict {
         Arc::make_mut(&mut self.0).insert(key, value);
     }
 
+    /// Whether the dictionary contains a specific key.
+    pub fn contains_key(&self, key: &str) -> bool {
+        self.0.contains_key(key)
+    }
+
     /// Clear the dictionary.
     pub fn clear(&mut self) {
         if Arc::strong_count(&self.0) == 1 {