feat(env): Rc

src/ty/internal/attrset.rs

@@ -1,5 +1,4 @@
 use std::collections::HashSet;
-use std::rc::Rc;
 
 use derive_more::Constructor;
 use itertools::Itertools;
@@ -43,7 +42,7 @@ impl<'vm> AttrSet<'vm> {
         self.data.get(&sym).is_some()
     }
 
-    pub fn capture(&mut self, env: &Rc<Env<'vm>>) {
+    pub fn capture(&mut self, env: &Env<'vm>) {
         self.data.iter().for_each(|(_, v)| match v.clone() {
             Value::Thunk(ref thunk) => {
                 thunk.capture(env.clone());