first documentation run

src/function.rs

@@ -10,7 +10,7 @@ use crate::{
 use core::fmt::Debug;
 use std::{cell::RefCell, fmt::Display, rc::Rc};
 
-/// A lox function.
+/// A Lox function with name, parameters, body, and closure environment.
 #[derive(Debug, Clone)]
 pub struct Function {
     pub name: Token,
@@ -62,6 +62,8 @@ impl Callable for Function {
 }
 
 impl Function {
+    /// Bind a method to an instance, creating a new function with "this" defined in its environment.
+    /// This allows methods to access the instance they belong to.
     pub fn bind(&self, instance: Rc<RefCell<Instance>>) -> Self {
         let mut env = Environment::with_enclosing(self.closure.clone());
         env.define("this".to_string(), Value::Instance(instance));