src/tools/rustbook/error.rs

   1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! Error handling utilities. WIP.
  12
  13 use std::error::Error;
  14 use std::fmt;
  15
  16 pub type CliError = Box<Error + 'static>;
  17 pub type CliResult<T> = Result<T, CliError>;
  18
  19 pub type CommandError = Box<Error + 'static>;
  20 pub type CommandResult<T> = Result<T, CommandError>;
  21
  22 pub fn err(s: &str) -> CliError {
  23     #[derive(Debug)]
  24     struct E(String);
  25
  26     impl Error for E {
  27         fn description(&self) -> &str { &self.0 }
  28     }
  29     impl fmt::Display for E {
  30         fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  31             self.0.fmt(f)
  32         }
  33     }
  34
  35     Box::new(E(s.to_string()))
  36 }