common_failures
: User-friendly io::Error
wrappers, quick_main!
and more
We provide support for:
- User-friendly
io::Error
wrappers with pathnames, - Formatting errors for display to the user (with the entire cause chain!), and
- Handy helper utilities like
quick_main!
.
Basically, the goal is to make failure
as ergonomic as possible, so that
everybody can stop re-inventing common bits of supporting code.
User-friendly io::Error
wrappers
By default, Rust's I/O errors do not include any information about the operation that failed. This means that you'll often see errors like:
No such file or directory (os error 2)
But it's much nicer for users if we print something like:
Error: error reading the file no-such-file.txt
caused by: No such file or directory (os error 2)
To do this, we can use io_read_context
and related functions:
use *;
use File;
use Path;
Formatting errors for display to the user
We also provide a support for formatting errors as strings, including the entire chain of "causes" of the error:
format!;
The quick_main!
macro
This is a replacement for quick_main!
from the error-chain
crate. It
generates a main
function that calls a second function returning Result<()>
,
and prints out any errors.
extern crate common_failures;
extern crate failure;
// This imports `Result`, `Error`, `failure::ResultExt`, and possibly
// other useful extension traits, to get you a minimal useful API.
use *;
// Uncomment this to define a `main` function that calls `run`, and prints
// any errors that it returns to standard error.
quick_main!;