Make environment generic and adapt closures

Added unit test

src/common/base_value.rs

@@ -2,6 +2,7 @@ use core::fmt;
 use std::fmt::Display;
 use std::ops::{Add, Div, Mul, Not, Rem, Sub};
 
+use crate::backend::environment::Environment;
 use crate::common::lox_result::{runtime_error, LoxResult};
 use crate::{
     backend::environment::EnvironmentStack,
@@ -312,7 +313,7 @@ pub struct LoxFunction {
     pub parameters: Vec<(String, String)>,
     pub return_type: Option<String>,
     pub body: AstNode<Stmt>,
-    pub closure: Option<EnvironmentStack>,
+    pub closure: Option<EnvironmentStack<BaseValue>>,
     pub guard: Option<Box<Expr>>,
 }
 
@@ -320,7 +321,7 @@ impl LoxFunction {
     pub fn new(
         parameters: Vec<(String, String)>,
         body: AstNode<Stmt>,
-        closure: Option<EnvironmentStack>,
+        closure: Option<EnvironmentStack<BaseValue>>,
         guard: Option<Box<Expr>>,
     ) -> Self {
         LoxFunction {

src/common/lox_result.rs

@@ -106,11 +106,7 @@ impl LoxError {
             LoxError::ParseError { source_slice, .. } => Some(source_slice.clone()),
             LoxError::IoError { .. } => None,
             LoxError::TypeMismatch { source_slice, .. } => Some(source_slice.clone()),
-            LoxError::Return {
-                value,
-                return_label,
-                ..
-            } => None,
+            LoxError::Return { .. } => None,
         }
     }