vendor/serde_derive_internals-0.16.0/src/ctxt.rs

   1 // Copyright 2017 Serde Developers
   2 //
   3 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   4 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   5 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   6 // option. This file may not be copied, modified, or distributed
   7 // except according to those terms.
   8
   9 use std::fmt::Display;
  10 use std::cell::RefCell;
  11
  12 #[derive(Default)]
  13 pub struct Ctxt {
  14     errors: RefCell<Option<Vec<String>>>,
  15 }
  16
  17 impl Ctxt {
  18     pub fn new() -> Self {
  19         Ctxt { errors: RefCell::new(Some(Vec::new())) }
  20     }
  21
  22     pub fn error<T: Display>(&self, msg: T) {
  23         self.errors
  24             .borrow_mut()
  25             .as_mut()
  26             .unwrap()
  27             .push(msg.to_string());
  28     }
  29
  30     pub fn check(self) -> Result<(), String> {
  31         let mut errors = self.errors.borrow_mut().take().unwrap();
  32         match errors.len() {
  33             0 => Ok(()),
  34             1 => Err(errors.pop().unwrap()),
  35             n => {
  36                 let mut msg = format!("{} errors:", n);
  37                 for err in errors {
  38                     msg.push_str("\n\t# ");
  39                     msg.push_str(&err);
  40                 }
  41                 Err(msg)
  42             }
  43         }
  44     }
  45 }
  46
  47 impl Drop for Ctxt {
  48     fn drop(&mut self) {
  49         if self.errors.borrow().is_some() {
  50             panic!("forgot to check for errors");
  51         }
  52     }
  53 }