erroneous - Helper for defining and using errors

erroneous is a crate with two features: - Its Error trait - Its Error derive

Example

```rust

[macro_use]

extern crate derive_more;

[macro_use]

extern crate erroneous;

[derive(Debug, Display, Error)]

enum ParseError { #[display(fmt = "Found an unexpected 'a' in the input")] UnexpectedA, #[display(fmt = "Found an unexpected 'b' in the input")] UnexpectedB, #[display(fmt = "Input was empty")] Empty, } ```

The Error trait

The Error trait is a supertrait of std::error::Error. It is automatically implemented for all implementors of std::error::Error, with some restrictions, particularly, it is Send + Sync + 'static. This means you have more freedom when dealing with them, and can in addition downcast dyn Error to concrete types. In addition, the trait also includes a helper method to iterate the chain of errors called iter.

The Error derive

This feature just implements std::error::Error (and thus also erroneous::Error) for you, You can annotate a field in your input as #[error(source)] to make the source method return that field.

License

erroneous is licensed under the terms of the MIT License or the Apache License 2.0, at your choosing.