Crate from_error_scope

Enable conversion between non-local Error types.

When using libraries, your code often needs to convert between Error types which aren’t part of your local crate. In this case you can’t implement std::error::FromError.

This is also useful if you need context dependent translation of error types.

Examples

Simple

#[macro_use] extern crate from_error_scope;

use from_error_scope::FromErrorScope;
use std::str::Utf8Error;
use std::io::CharsError;

struct ErrorScope;

impl FromErrorScope<Utf8Error, CharsError> for ErrorScope {
    fn from_error(&self, err: Utf8Error) -> CharsError {
       CharsError::NotUtf8
    }
}

fn from_utf8(v: &[u8]) -> Result<&str, CharsError> {
    Ok(trys!(ErrorScope, std::str::from_utf8(v)))
}

fn main () {
    let abc = vec![65,66,67];
    println!("{}", from_utf8(&abc).unwrap())
}

Macros

trys

A try! like macro that takes an additional type argument for a type that implements FromErrorScope. You may wish to wrap this macro for a specific error scope, to shorten invocations.

Traits

FromErrorScope

A FromError like trait, that can be implemented on an explicit Scope type, enabling conversion between non-local Error types.