use std::fmt::Display;
use std::cell::RefCell;
#[derive(Default)]
pub struct Ctxt {
errors: RefCell<Option<Vec<String>>>,
}
impl Ctxt {
pub fn new() -> Self {
Ctxt {
errors: RefCell::new(Some(Vec::new())),
}
}
pub fn error<T: Display>(&self, msg: T) {
self.errors.borrow_mut().as_mut().unwrap().push(msg.to_string());
}
pub fn check(self) -> Result<(), String> {
let mut errors = self.errors.borrow_mut().take().unwrap();
match errors.len() {
0 => Ok(()),
1 => Err(errors.pop().unwrap()),
n => {
let mut msg = format!("{} errors:", n);
for err in errors {
msg.push_str("\n\t# ");
msg.push_str(&err);
}
Err(msg)
}
}
}
}
impl Drop for Ctxt {
fn drop(&mut self) {
if self.errors.borrow().is_some() {
panic!("forgot to check for errors");
}
}
}