37 lines
894 B
Rust
37 lines
894 B
Rust
use crate::object::Object;
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use std::cell::RefCell;
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use std::collections::HashMap;
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use std::rc::Rc;
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#[derive(Debug, PartialEq, Default)]
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pub struct Environment {
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store: HashMap<String, Object>,
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outer: Option<Rc<RefCell<Environment>>>,
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}
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impl Environment {
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pub fn new() -> Self {
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Default::default()
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}
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pub fn extend(outer: Rc<RefCell<Self>>) -> Environment {
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Environment {
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store: HashMap::new(),
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outer: Some(outer),
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}
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}
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pub fn get(&self, name: &str) -> Option<Object> {
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match self.store.get(name) {
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Some(value) => Some(value.clone()),
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None => self
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.outer
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.as_ref()
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.and_then(|o| o.borrow().get(name).clone()),
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}
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}
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pub fn set(&mut self, name: &str, val: Object) {
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self.store.insert(name.to_string(), val);
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}
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} |