Add Scope::get.

CHANGELOG.md

@@ -24,6 +24,7 @@ Enhancements
 * `Engine::def_tag`, `Engine::def_tag_mut` and `Engine::set_tag` are added to manage a default value for the custom evaluation state, accessible via `EvalState::tag()` (which is the same as `NativeCallContext::tag()`).
 * Originally, the debugger's custom state uses the same state as `EvalState::tag()` (which is the same as `NativeCallContext::tag()`).  It is now split into its own variable accessible under `Debugger::state()`.
 * Non-borrowed string keys can now be deserialized for object maps via `serde`.
+* `Scope::get` is added to get a reference to a variable's value.
 
 
 Version 1.7.0

src/types/scope.rs

@@ -511,9 +511,33 @@ impl Scope<'_> {
         }
         self
     }
+    /// Get a reference to an entry in the [`Scope`].
+    ///
+    /// If the entry by the specified name is not found, [`None`] is returned.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use rhai::Scope;
+    ///
+    /// let mut my_scope = Scope::new();
+    ///
+    /// my_scope.push("x", 42_i64);
+    ///
+    /// let value = my_scope.get("x").expect("x should exist");
+    ///
+    /// assert_eq!(value.as_int().unwrap(), 42);
+    ///
+    /// assert!(my_scope.get("z").is_none());
+    /// ```
+    #[inline(always)]
+    #[must_use]
+    pub fn get(&self, name: &str) -> Option<&Dynamic> {
+        self.get_index(name).map(|(index, _)| &self.values[index])
+    }
     /// Get a mutable reference to an entry in the [`Scope`].
     ///
-    /// If the entry by the specified name is not found, of if it is read-only,
+    /// If the entry by the specified name is not found, or if it is read-only,
     /// [`None`] is returned.
     ///
     /// # Example
@@ -531,8 +555,8 @@ impl Scope<'_> {
     ///
     /// assert_eq!(my_scope.get_value::<i64>("x").expect("x should exist"), 123);
     ///
-    /// my_scope.push_constant("Z", 1_i64);
-    /// assert!(my_scope.get_mut("Z").is_none());
+    /// my_scope.push_constant("z", 1_i64);
+    /// assert!(my_scope.get_mut("z").is_none());
     /// ```
     #[inline]
     #[must_use]