use std::collections::HashMap;
use std::rc::Rc;
use std::cell::RefCell;
use crate::object::Object;
pub type Env = Rc<RefCell<Environment>>;
#[derive(Debug, Default, Clone, PartialEq)]
pub struct Environment {
store: HashMap<String, Rc<Object>>,
outer: Option<Env>
}
impl Environment {
pub fn new_enclosed_environment(outer: &Env) -> Self {
let mut env: Environment = Default::default();
env.outer = Some(Rc::clone(outer));
return env;
}
pub fn get(&self, name: &str) -> Option<Rc<Object>> {
match self.store.get(name) {
Some(obj) => Some(Rc::clone(obj)),
None => {
if let Some(outer) = &self.outer {
return outer.borrow().get(name);
} else {
return None;
}
}
}
}
pub fn set(&mut self, name: String, val: Rc<Object>) {
self.store.insert(name, val);
}
}