Display error messages inspired by The Wicker Man in your Rust code

This crate is meant to illustrate how to make a simple procedural macro in Rust. There is an accompanying blog post that explains what procedural macros are and how to make them:

• Introdution to Procedural Macros

To see the error message above, add wickerman as a dependency in your Cargo.toml:

# Cargo.toml
[dependencies]
wickerman = {git = "https://github.com/zmitchell/wickerman"}

then use wickerman::wickerman in a crate with procedural macros enabled:

#![feature(proc_macro)]

extern crate wickerman;
use wickerman::wickerman;

and, finally, apply the #[wickerman] attribute to a struct containing a field named "bees".

#[wickerman]
struct Foo {
    bees: i32,
}

To see even more absurd error messages, add the go-nuts feature to Cargo.toml, and apply the attribute to a struct with several fields.

# Cargo.toml
[dependencies]
wickerman = {git = "https://github.com/zmitchell/wickerman", features = ["go-nuts"]}

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.