45 lines
1.2 KiB
Rust
45 lines
1.2 KiB
Rust
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use std::collections::HashMap;
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use crate::{
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frontend::{source_registry::SourceSlice, tokens::LiteralValue},
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result::{LoxError, LoxResult},
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};
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pub struct Environment<'a> {
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values: HashMap<String, LiteralValue>,
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parent: Option<&'a Environment<'a>>,
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}
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impl<'a> Environment<'a> {
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pub fn new() -> Self {
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Environment {
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values: HashMap::new(),
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parent: None,
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}
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}
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pub fn new_with_parent(parent: &'a Environment<'a>) -> Self {
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Environment {
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values: HashMap::new(),
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parent: Some(parent),
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}
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}
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pub fn get(&self, name: &str) -> LoxResult<LiteralValue> {
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match self.values.get(name) {
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Some(value) => Ok(value.clone()),
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None => match self.parent {
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Some(parent) => parent.get(name),
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None => Err(LoxError::RuntimeError {
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source_slice: SourceSlice::default(), // todo change this to the actual source slice
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message: format!("Undefined variable '{}'", name),
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}),
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},
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}
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}
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pub fn set(&mut self, name: String, value: LiteralValue) {
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self.values.insert(name, value);
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}
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}
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