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// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Error handling utilities. WIP.
use std::fmt;
use std::fmt::{Debug, Formatter};
use std::old_io::IoError;
pub type CliError = Box<Error + 'static>;
pub type CliResult<T> = Result<T, CliError>;
pub type CommandError = Box<Error + 'static>;
pub type CommandResult<T> = Result<T, CommandError>;
pub trait Error {
fn description(&self) -> &str;
fn detail(&self) -> Option<&str> { None }
fn cause(&self) -> Option<&Error> { None }
}
pub trait FromError<E> {
fn from_err(err: E) -> Self;
}
impl Debug for Box<Error + 'static> {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
write!(f, "{}", self.description())
}
}
impl<E: Error + 'static> FromError<E> for Box<Error + 'static> {
fn from_err(err: E) -> Box<Error + 'static> {
box err as Box<Error>
}
}
impl<'a> Error for &'a str {
fn description<'b>(&'b self) -> &'b str {
*self
}
}
impl Error for String {
fn description<'a>(&'a self) -> &'a str {
&self[]
}
}
impl<'a> Error for Box<Error + 'a> {
fn description(&self) -> &str { (**self).description() }
fn detail(&self) -> Option<&str> { (**self).detail() }
fn cause(&self) -> Option<&Error> { (**self).cause() }
}
impl FromError<()> for () {
fn from_err(_: ()) -> () { () }
}
impl FromError<IoError> for IoError {
fn from_err(error: IoError) -> IoError { error }
}
impl Error for IoError {
fn description(&self) -> &str {
self.desc
}
fn detail(&self) -> Option<&str> {
self.detail.as_ref().map(|s| &s[])
}
}
//fn iter_map_err<T, U, E, I: Iterator<Result<T,E>>>(iter: I,
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