easily build compiler plugins.

Sorry, you need to build the document with cargo doc.

ecp required latest Nightly Rust.

I need not only "custom derive", but also more "compiler plugin" features. Currently "Macros 1.1" is also unstable.

"Macros 1.1" has been stabilize in Rust 1.15, so you should use it.

I will consider adding support for syn.

Add dependencies to Cargo.toml

[dependencies]
ecp = "^0.1"

In your main.rs or lib.rs:

#![feature(quote, plugin_registrar, rustc_private)]
extern crate syntax;
extern crate ecp;

Create a simple macro which prints "Hello world!":

#![feature(quote, plugin_registrar, rustc_private)]
extern crate syntax;
extern crate ecp;
use ecp::prelude::*;

#[plugin_registrar]
pub fn register(reg: &mut Registry) {
    reg.register_macro("test", test);
}

pub fn test(cx: &mut ExtCtxt, _: Span, _: &[TokenTree]) -> Box<MacResult + 'static> {
    MacEager::expr(quote_expr!(cx, println!("Hello world!")))
}

ecp is primarily distributed under the terms of the MIT license. See LICENSE for details.