# Easy-error
[](https://docs.rs/easy-error)
[](http://crates.io/crates/easy-error)
This crate is a lightweight error handling library meant to play well with the standard `Error` trait.
It is designed for quick prototyping or for Command-line applications where any error will simply bubble up to the user.
There are four major components of this crate:
1. A basic, string-based error type that is meant for either quick prototyping or human-facing errors.
2. A nice way to iterate over the causes of an error.
3. Some macros that make returning errors slightly more ergonomic.
4. A "termination" type that produces nicely formatted error messages when returned from the `main` function.
## Rust Version Requirements
The current version requires **Rustc 1.46 or newer**.
In general, this crate will be compilable with the Rustc version available on the oldest supported Ubuntu LTS release.
Any change that requires a newer version of Rustc than what is available on the oldest supported Ubuntu LTS will be considered a breaking change.
## Example
```rust
use std::{fs::File, io::Read};
use easy_error::{bail, ensure, Error, ResultExt, Terminator};
fn from_file() -> Result<i32, Error> {
let file_name = "example.txt";
let mut file = File::open(file_name).context("Could not open file")?;
let mut contents = String::new();
file.read_to_string(&mut contents).context("Unable to read file")?;
contents.trim().parse().context("Could not parse file")
}
fn validate(value: i32) -> Result<(), Error> {
ensure!(value > 0, "Value must be greater than zero (found {})", value);
if value % 2 == 1 {
bail!("Only even numbers can be used");
}
Ok(())
}
fn main() -> Result<(), Terminator> {
let value = from_file().context("Unable to get value from file")?;
validate(value).context("Value is not acceptable")?;
println!("Value = {}", value);
Ok(())
}
```