commit	6c9f5b6426c4302281c541059ce4f739427bf98c	[log] [tgz]
author	David Tolnay <dtolnay@gmail.com>	Tue Sep 13 15:19:22 2016 -0700
committer	David Tolnay <dtolnay@gmail.com>	Tue Sep 13 15:19:22 2016 -0700
tree	3dc9ede1949d7df9fe5fb490cae486971cb50507
parent	0fc2a1674458a38e4b560c2711fadf0b9c02ac9f [diff]

tree: 3dc9ede1949d7df9fe5fb490cae486971cb50507

README.md

Nom parser for Rust items

Parse Rust structs and enums without a Syntex dependency, intended for use with Macros 1.1.

Designed for fast compile time.

Compile time for syn (from scratch including all dependencies): 6 seconds
Compile time for the syntex/quasi/aster stack: 60+ seconds

[dependencies]
syn = "0.5"

extern crate syn;

let raw = "
    #[derive(Debug, Clone, Eq, PartialEq)]
    pub struct Item {
        pub ident: Ident,
        pub vis: Visibility,
        pub attrs: Vec<Attribute>,
        pub generics: Generics,
        pub body: Body,
    }
";

let ast = syn::parse_item(raw).unwrap();

Usage with Macros 1.1

// lib.rs
#![crate_type = "rustc-macro"]
#![feature(rustc_macro, rustc_macro_lib)]

extern crate rustc_macro;

#[macro_use]
extern crate quote;
extern crate syn;

use rustc_macro::TokenStream;

#[rustc_macro_derive(SpecialItem)]
pub fn special_item(input: TokenStream) -> TokenStream {
    let source = input.to_string();

    // Parse a string of items to an AST
    let ast = syn::parse_item(&source).unwrap();

    // Build the output, possibly using quasi-quotation
    let expanded = quote! {
        // ...
    };

    // Parse this back to a token stream and return it
    expanded.to_string().parse().unwrap()
}

# Cargo.toml
# ...
[dependencies]
syn = "0.5"
quote = "0.1"

[lib]
rustc-macro = true

License

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.

Contribution

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