trackable

trackable provides functionalities to define trackable objects and track those.

Documentation

Below code is an example that tracks failure of an I/O operation:

#[macro_use]
extern crate trackable;

use trackable::error::{Failed, Failure, ErrorKindExt};

fn foo() -> Result<(), Failure> {
    track_try!(std::fs::File::open("/path/to/non_existent_file")
               .map_err(|e| Failed.cause(e)));
    Ok(())
}
fn bar() -> Result<(), Failure> {
    track_try!(foo());
    Ok(())
}
fn baz() -> Result<(), Failure> {
    track_try!(bar());
    Ok(())
}

fn main() {
    let result = baz();
    assert!(result.is_err());

    let error = result.err().unwrap();
    assert_eq!(format!("\r{}", error), r#"
Failed (cause; No such file or directory)
HISTORY:
  [0] at rust_out:<anon>:7
  [1] at rust_out:<anon>:12
  [2] at rust_out:<anon>:16
"#);
}

This example used the built-in Failure type, but you can easily define your own trackable error types. See the documentaion of error module for more details.

Installation

Add following lines to your Cargo.toml:

[dependencies]
trackable = "0.1"