Support passing JS objects through Rust

src/lib.rs

@@ -2,11 +2,54 @@
 
 extern crate wasm_bindgen_macro;
 
+use std::mem;
+
 pub mod prelude {
     pub use wasm_bindgen_macro::wasm_bindgen;
-    pub use Object;
+    pub use JsObject;
 }
 
-pub struct Object {
+pub struct JsObject {
     idx: u32,
 }
+
+impl JsObject {
+    #[doc(hidden)]
+    pub fn __from_idx(idx: u32) -> JsObject {
+        JsObject { idx }
+    }
+
+    #[doc(hidden)]
+    pub fn __get_idx(&self) -> u32 {
+        self.idx
+    }
+
+    #[doc(hidden)]
+    pub fn __into_idx(self) -> u32 {
+        let ret = self.idx;
+        mem::forget(self);
+        return ret
+    }
+}
+
+extern {
+    fn __wasm_bindgen_object_clone_ref(idx: u32) -> u32;
+    fn __wasm_bindgen_object_drop_ref(idx: u32);
+}
+
+impl Clone for JsObject {
+    fn clone(&self) -> JsObject {
+        unsafe {
+            let idx = __wasm_bindgen_object_clone_ref(self.idx);
+            JsObject { idx }
+        }
+    }
+}
+
+impl Drop for JsObject {
+    fn drop(&mut self) {
+        unsafe {
+            __wasm_bindgen_object_drop_ref(self.idx);
+        }
+    }
+}