fix: add evironment to eval program

src/evaluator/mod.rs

@@ -8,8 +8,10 @@ const NULL: Null = Null;
 const BOOL_TRUE: object::Boolean = object::Boolean { value: true };
 const BOOL_FALSE: object::Boolean = object::Boolean { value: false };
 
-pub fn eval_program(program: ast::Program) -> Option<Box<dyn Object>> {
+pub fn eval_program(
-    let env = Rc::new(RefCell::new(Environment::new()));
+    program: ast::Program,
+    env: Rc<RefCell<Environment>>,
+) -> Option<Box<dyn Object>> {
     let mut result: Option<Box<dyn Object>> = None;
 
     for stmt in program.statements {

src/evaluator/tests.rs

@@ -1,12 +1,17 @@
+use std::cell::RefCell;
+use std::rc::Rc;
+
 use super::*;
 use crate::lexer;
+use crate::object::Environment;
 use crate::parser::new_parser;
 
 fn test_eval(input: &str) -> Option<Box<dyn Object>> {
     let lexer = lexer::new(input.to_string());
     let mut parser = new_parser(lexer);
     let program = parser.parse_program();
-    eval_program(program)
+    let env = Rc::new(RefCell::new(Environment::new()));
+    eval_program(program, env)
 }
 
 fn test_integer_object(obj: &dyn Object, expected: i64) {

src/repl/mod.rs

@@ -1,5 +1,9 @@
+use std::cell::RefCell;
+use std::rc::Rc;
+
 use crate::evaluator;
 use crate::lexer::new;
+use crate::object::Environment;
 use crate::parser::Parser;
 use crate::parser::new_parser;
 
@@ -7,6 +11,7 @@ const PROMPT: &str = ">> ";
 
 pub fn start_repl() {
     println!("Welcome to the REPL! Type 'exit' to quit.");
+    let env = Rc::new(RefCell::new(Environment::new()));
     loop {
         print!("{}", PROMPT);
         let mut input = String::new();
@@ -20,7 +25,7 @@ pub fn start_repl() {
         let lexer = new(input.to_string());
         let mut parser: Parser = new_parser(lexer);
         let program = parser.parse_program();
-        let evaluated = evaluator::eval_program(program);
+        let evaluated = evaluator::eval_program(program, Rc::clone(&env));
 
         for err in parser.errors() {
             eprintln!("ERROR: {}", err);