Implement closures.

tests/closures.rs

@@ -35,7 +35,8 @@ fn test_fn_ptr_curry_call() -> Result<(), Box<EvalAltResult>> {
 }
 
 #[test]
-#[cfg(all(not(feature = "no_capture"), not(feature = "no_object")))]
+#[cfg(not(feature = "no_closure"))]
+#[cfg(not(feature = "no_object"))]
 fn test_closures() -> Result<(), Box<EvalAltResult>> {
     let engine = Engine::new();
 
@@ -56,5 +57,61 @@ fn test_closures() -> Result<(), Box<EvalAltResult>> {
         42
     );
 
+    assert_eq!(
+        engine.eval::<INT>(
+            r#"
+                let a = 41;
+                let foo = |x| { a += x };
+                foo.call(1);
+                a
+            "#
+        )?,
+        42
+    );
+
+    assert!(engine.eval::<bool>(
+        r#"
+            let a = 41;
+            let foo = |x| { a += x };
+            a.is_shared()
+        "#
+    )?);
+
+    Ok(())
+}
+
+#[test]
+#[cfg(not(feature = "no_closure"))]
+#[cfg(not(feature = "no_object"))]
+fn test_closures_data_race() -> Result<(), Box<EvalAltResult>> {
+    let engine = Engine::new();
+
+    assert_eq!(
+        engine.eval::<INT>(
+            r#"
+                    let a = 1;
+                    let b = 40;
+                    let foo = |x| { this += a + x };
+                    b.call(foo, 1);
+                    b
+                "#
+        )?,
+        42
+    );
+
+    assert!(matches!(
+        *engine
+            .eval::<INT>(
+                r#"
+                        let a = 20;
+                        let foo = |x| { this += a + x };
+                        a.call(foo, 1);
+                        a
+                    "#
+            )
+            .expect_err("should error"),
+        EvalAltResult::ErrorDataRace(_, _)
+    ));
+
     Ok(())
 }