mirror of
https://github.com/haraldh/chainerror.git
synced 2024-10-05 20:15:11 +02:00
56 lines
1.2 KiB
Rust
56 lines
1.2 KiB
Rust
/*!
|
|
|
|
~~~bash
|
|
$ cargo run -q --example tutorial8
|
|
Func1Error: func1 error
|
|
Func2Error: Error reading 'foo.txt'
|
|
Debug Func2Error:
|
|
examples/tutorial8.rs:27: Func2Error(Error reading 'foo.txt')
|
|
Caused by:
|
|
Kind(NotFound)
|
|
~~~
|
|
|
|
!*/
|
|
|
|
use chainerror::prelude::*;
|
|
use std::error::Error;
|
|
use std::io;
|
|
use std::result::Result;
|
|
|
|
fn do_some_io() -> Result<(), Box<Error>> {
|
|
Err(io::Error::from(io::ErrorKind::NotFound))?;
|
|
Ok(())
|
|
}
|
|
|
|
derive_str_cherr!(Func2Error);
|
|
|
|
fn func2() -> Result<(), Box<Error>> {
|
|
let filename = "foo.txt";
|
|
do_some_io().map_err(mstrerr!(Func2Error, "Error reading '{}'", filename))?;
|
|
Ok(())
|
|
}
|
|
|
|
derive_str_cherr!(Func1Error);
|
|
|
|
fn func1() -> Result<(), Box<Error>> {
|
|
func2().map_err(mstrerr!(Func1Error, "func1 error"))?;
|
|
Ok(())
|
|
}
|
|
|
|
fn main() -> Result<(), Box<Error>> {
|
|
if let Err(e) = func1() {
|
|
if let Some(f1err) = e.downcast_chain_ref::<Func1Error>() {
|
|
eprintln!("Func1Error: {}", f1err);
|
|
|
|
if let Some(f2err) = f1err.find_cause::<ChainError<Func2Error>>() {
|
|
eprintln!("Func2Error: {}", f2err);
|
|
}
|
|
|
|
if let Some(f2err) = f1err.find_chain_cause::<Func2Error>() {
|
|
eprintln!("Debug Func2Error:\n{:?}", f2err);
|
|
}
|
|
}
|
|
}
|
|
Ok(())
|
|
}
|