schala/schala-lang/language/src/util.rs

61 lines
1.6 KiB
Rust

use std::collections::HashMap;
use std::hash::Hash;
use std::cmp::Eq;
use std::ops::Deref;
pub fn deref_optional_box<T>(x: &Option<Box<T>>) -> Option<&T> {
x.as_ref().map(|b: &Box<T>| Deref::deref(b))
}
#[derive(Default, Debug)]
pub struct ScopeStack<'a, T: 'a, V: 'a> where T: Hash + Eq {
parent: Option<&'a ScopeStack<'a, T, V>>,
values: HashMap<T, V>,
scope_name: Option<String>
}
impl<'a, T, V> ScopeStack<'a, T, V> where T: Hash + Eq {
pub fn new(name: Option<String>) -> ScopeStack<'a, T, V> where T: Hash + Eq {
ScopeStack {
parent: None,
values: HashMap::new(),
scope_name: name
}
}
pub fn insert(&mut self, key: T, value: V) where T: Hash + Eq {
self.values.insert(key, value);
}
pub fn lookup(&self, key: &T) -> Option<&V> where T: Hash + Eq {
match (self.values.get(key), self.parent) {
(None, None) => None,
(None, Some(parent)) => parent.lookup(key),
(Some(value), _) => Some(value),
}
}
pub fn new_scope(&'a self, name: Option<String>) -> ScopeStack<'a, T, V> where T: Hash + Eq {
ScopeStack {
parent: Some(self),
values: HashMap::default(),
scope_name: name,
}
}
#[allow(dead_code)]
pub fn get_name(&self) -> Option<&String> {
self.scope_name.as_ref()
}
}
/// this is intended for use in tests, and does no error-handling whatsoever
#[allow(dead_code)]
pub fn quick_ast(input: &str) -> crate::ast::AST {
let tokens = crate::tokenizing::tokenize(input);
let mut parser = crate::parsing::Parser::new(tokens);
parser.parse().unwrap()
}
#[allow(unused_macros)]
macro_rules! rc {
($string:tt) => { Rc::new(stringify!($string).to_string()) }
}