fix performance issue by using reference counting for objects

src/lib.rs

@@ -13,6 +13,8 @@ use std::fmt::Display;
 use std::io::BufRead;
 use std::fmt;
 use std::iter::Peekable;
+use std::rc::Rc;
+use std::cell::RefCell;
 
 #[derive(Clone, Debug)]
 pub enum Type {
@@ -101,13 +103,13 @@ enum Cache {
 
 #[derive(Clone, Debug, PartialEq)]
 struct Object {
-    locals: HashMap<String, Object>,
-    globals: HashMap<String, Object>,
+    locals: HashMap<String, Rc<RefCell<Object>>>,
+    globals: HashMap<String, Rc<RefCell<Object>>>,
     value: Cache,
 }
 
 impl Object {
-    pub fn variable(tree: ParseTree, globals: HashMap<String, Object>, locals: HashMap<String, Object>) -> Self {
+    pub fn variable(tree: ParseTree, globals: HashMap<String, Rc<RefCell<Object>>>, locals: HashMap<String, Rc<RefCell<Object>>>) -> Self {
         Self {
             locals,
             globals,
@@ -115,7 +117,7 @@ impl Object {
         }
     }
 
-    pub fn value(v: Value, globals: HashMap<String, Object>, locals: HashMap<String, Object>) -> Self {
+    pub fn value(v: Value, globals: HashMap<String, Rc<RefCell<Object>>>, locals: HashMap<String, Rc<RefCell<Object>>>) -> Self {
         Self {
             locals,
             globals,
@@ -123,7 +125,7 @@ impl Object {
         }
     }
 
-    pub fn function(func: Function, globals: HashMap<String, Object>, locals: HashMap<String, Object>) -> Self {
+    pub fn function(func: Function, globals: HashMap<String, Rc<RefCell<Object>>>, locals: HashMap<String, Rc<RefCell<Object>>>) -> Self {
         Self {
             locals,
             globals,
@@ -150,11 +152,11 @@ impl Object {
         }
     }
 
-    pub fn locals(&self) -> HashMap<String, Object> {
+    pub fn locals(&self) -> HashMap<String, Rc<RefCell<Object>>> {
         self.locals.clone()
     }
 
-    pub fn globals(&self) -> HashMap<String, Object> {
+    pub fn globals(&self) -> HashMap<String, Rc<RefCell<Object>>> {
         self.globals.clone()
     }
 }
@@ -162,7 +164,7 @@ impl Object {
 pub struct Runtime<'a, R: BufRead> {
     tokenizer: Peekable<Tokenizer<R>>,
     global_types: HashMap<String, Type>,
-    globals: HashMap<String, Object>,
+    globals: HashMap<String, Rc<RefCell<Object>>>,
     parser: Option<Parser<'a, Tokenizer<R>>>,
 }