├── .gitignore ├── examples └── main.rs ├── tests └── test.rs ├── .travis.yml ├── Cargo.toml ├── LICENSE-MIT ├── README.md ├── src └── lib.rs └── LICENSE-APACHE /.gitignore: -------------------------------------------------------------------------------- 1 | coverage/ 2 | target/ 3 | tmp/ 4 | dist/ 5 | npm-debug.log* 6 | Cargo.lock 7 | .DS_Store 8 | -------------------------------------------------------------------------------- /examples/main.rs: -------------------------------------------------------------------------------- 1 | use async_std::task; 2 | 3 | #[async_attributes::main] 4 | async fn main() { 5 | task::spawn(async { 6 | println!("Hello, world!"); 7 | }) 8 | .await; 9 | } 10 | -------------------------------------------------------------------------------- /tests/test.rs: -------------------------------------------------------------------------------- 1 | use async_attributes::test; 2 | 3 | #[async_attributes::test] 4 | async fn test() -> std::io::Result<()> { 5 | assert_eq!(2 * 2, 4); 6 | Ok(()) 7 | } 8 | 9 | #[test] 10 | async fn aliased_test() -> std::io::Result<()> { 11 | assert!(true); 12 | Ok(()) 13 | } 14 | -------------------------------------------------------------------------------- /.travis.yml: -------------------------------------------------------------------------------- 1 | language: rust 2 | rust: 3 | - nightly 4 | 5 | before_script: | 6 | rustup component add rustfmt-preview; 7 | if ! rustup component add rustfmt; then 8 | target=`curl https://rust-lang.github.io/rustup-components-history/x86_64-unknown-linux-gnu/rustfmt`; 9 | echo "'rustfmt' is unavailable on the toolchain 'nightly', use the toolchain 'nightly-$target' instead"; 10 | rustup toolchain install nightly-$target; 11 | rustup default nightly-$target; 12 | rustup component add rustfmt; 13 | fi 14 | script: | 15 | cargo fmt -- --check && 16 | cargo build --verbose && 17 | cargo test --verbose 18 | cache: cargo 19 | -------------------------------------------------------------------------------- /Cargo.toml: -------------------------------------------------------------------------------- 1 | [package] 2 | name = "async-attributes" 3 | description = "Experimental language-level polyfills for Async Rust." 4 | version = "1.1.2" 5 | license = "MIT OR Apache-2.0" 6 | readme = "README.md" 7 | repository = "https://github.com/async-rs/async-attributes" 8 | homepage = "https://github.com/async-rs/async-attributes" 9 | documentation = "https://docs.rs/async-attributes" 10 | authors = ["Yoshua Wuyts "] 11 | keywords = ["async", "await", "macro", "futures"] 12 | categories = ["asynchronous", "network-programming", "filesystem", "concurrency", "api-bindings"] 13 | edition = "2018" 14 | 15 | [lib] 16 | proc-macro = true 17 | 18 | [dependencies] 19 | syn = { version = "1.0", features = ["full"] } 20 | quote = "1.0" 21 | 22 | [dev-dependencies] 23 | async-std = "1.9.0" 24 | -------------------------------------------------------------------------------- /LICENSE-MIT: -------------------------------------------------------------------------------- 1 | The MIT License (MIT) 2 | 3 | Copyright (c) 2019 Yoshua Wuyts 4 | 5 | Permission is hereby granted, free of charge, to any person obtaining a copy 6 | of this software and associated documentation files (the "Software"), to deal 7 | in the Software without restriction, including without limitation the rights 8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 9 | copies of the Software, and to permit persons to whom the Software is 10 | furnished to do so, subject to the following conditions: 11 | 12 | The above copyright notice and this permission notice shall be included in all 13 | copies or substantial portions of the Software. 14 | 15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 21 | SOFTWARE. 22 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # async-attributes 2 | [![crates.io version][1]][2] [![build status][3]][4] 3 | [![downloads][5]][6] [![docs.rs docs][7]][8] 4 | 5 | Experimental language-level polyfills for Async Rust. 6 | 7 | - [Documentation][8] 8 | - [Crates.io][2] 9 | - [Releases][releases] 10 | 11 | ## Examples 12 | 13 | ```rust 14 | #[async_attributes::main] 15 | async fn main() { 16 | println!("Hello, world!"); 17 | } 18 | ``` 19 | 20 | ## About 21 | 22 | Async Rust is a work in progress. The language has enabled us to do some 23 | fantastic things, but not everything is figured out yet. This crate exists 24 | to polyfill language-level support for async idioms before they can be part 25 | of the language. 26 | 27 | A great example of this is `async fn main`, which we first introduced as 28 | part of the [`runtime`](https://docs.rs/runtime/0.3.0-alpha.7/runtime/) crate. 29 | Its premise is that if `async fn` is required for every `await` call, it 30 | makes sense to apply that even to `fn main`. Unfortunately this would 31 | require compiler support to enable, so we've provided an experimental 32 | polyfill for it in the mean time. 33 | 34 | ## Why isn't this crate part of async-std? 35 | 36 | We want to make sure `async-std`'s surface area is stable, and only includes 37 | things that would make sense to be part of "an async version of std". 38 | Language level support is really important, but _not_ part of the standard 39 | library. 40 | 41 | This has some distinct benefits: in particular it allows us to 42 | version both crates at a different pace. And as features are added to the 43 | language (or we decide they weren't a great idea after all), we can 44 | incrementally shrink the surface area of this crate. 45 | 46 | The other big benefit is that it allows libraries to depend on `async-std` 47 | without needing to pull in the rather heavy `syn`, `quote`, and 48 | `proc-macro2` crates. This should help keep compilation times snappy for 49 | everyone. 50 | 51 | ## Installation 52 | 53 | ```sh 54 | $ cargo add async-attributes 55 | ``` 56 | 57 | ## Safety 58 | This crate uses ``#![deny(unsafe_code)]`` to ensure everything is implemented in 59 | 100% Safe Rust. 60 | 61 | ## Contributing 62 | Want to join us? Check out our ["Contributing" guide][contributing] and take a 63 | look at some of these issues: 64 | 65 | - [Issues labeled "good first issue"][good-first-issue] 66 | - [Issues labeled "help wanted"][help-wanted] 67 | 68 | ## References 69 | - https://docs.rs/runtime-attributes - our original experiments with 70 | `async fn main`. 71 | - https://docs.rs/async-trait - async trait support by the fantastic 72 | [David Tolnay](https://github.com/dtolnay/). 73 | - https://docs.rs/futures-async-stream - for iterating and defining streams by 74 | the skilled [Taiki Endo](https://github.com/taiki-e/). 75 | 76 | ## License 77 | [MIT](./LICENSE-MIT) OR [Apache-2.0](./LICENSE-APACHE) 78 | 79 | [1]: https://img.shields.io/crates/v/async-attributes.svg?style=flat-square 80 | [2]: https://crates.io/crates/async-attributes 81 | [3]: https://travis-ci.com/async-rs/async-attributes.svg?branch=master 82 | [4]: https://travis-ci.com/async-rs/async-attributes 83 | [5]: https://img.shields.io/crates/d/async-attributes.svg?style=flat-square 84 | [6]: https://crates.io/crates/async-attributes 85 | [7]: https://img.shields.io/badge/docs-latest-blue.svg?style=flat-square 86 | [8]: https://docs.rs/async-attributes 87 | 88 | [releases]: https://github.com/async-rs/async-attributes/releases 89 | [contributing]: https://github.com/async-rs/async-attributes/blob/master.github/CONTRIBUTING.md 90 | [good-first-issue]: https://github.com/async-rs/async-attributes/labels/good%20first%20issue 91 | [help-wanted]: https://github.com/async-rs/async-attributes/labels/help%20wanted 92 | -------------------------------------------------------------------------------- /src/lib.rs: -------------------------------------------------------------------------------- 1 | //! Experimental language-level polyfills for Async Rust. 2 | //! 3 | //! # Examples 4 | //! 5 | //! ``` 6 | //! #[async_attributes::main] 7 | //! async fn main() { 8 | //! println!("Hello, world!"); 9 | //! } 10 | //! ``` 11 | //! 12 | //! # About 13 | //! 14 | //! Async Rust is a work in progress. The language has enabled us to do some 15 | //! fantastic things, but not everything is figured out yet. This crate exists 16 | //! to polyfill language-level support for async idioms before they can be part 17 | //! of the language. 18 | //! 19 | //! A great example of this is `async fn main`, which we first introduced as 20 | //! part of the [`runtime`](https://docs.rs/runtime/0.3.0-alpha.7/runtime/) crate. 21 | //! Its premise is that if `async fn` is required for every `await` call, it 22 | //! makes sense to apply that even to `fn main`. Unfortunately this would 23 | //! require compiler support to enable, so we've provided an experimental 24 | //! polyfill for it in the mean time. 25 | 26 | #![forbid(unsafe_code, future_incompatible, rust_2018_idioms)] 27 | #![deny(missing_debug_implementations, nonstandard_style)] 28 | #![recursion_limit = "512"] 29 | 30 | use proc_macro::TokenStream; 31 | use quote::{quote, quote_spanned}; 32 | use syn::spanned::Spanned; 33 | 34 | /// Enables an async main function. 35 | /// 36 | /// # Examples 37 | /// 38 | /// ```ignore 39 | /// #[async_std::main] 40 | /// async fn main() -> std::io::Result<()> { 41 | /// Ok(()) 42 | /// } 43 | /// ``` 44 | #[cfg(not(test))] // NOTE: exporting main breaks tests, we should file an issue. 45 | #[proc_macro_attribute] 46 | pub fn main(_attr: TokenStream, item: TokenStream) -> TokenStream { 47 | let input = syn::parse_macro_input!(item as syn::ItemFn); 48 | 49 | let ret = &input.sig.output; 50 | let inputs = &input.sig.inputs; 51 | let name = &input.sig.ident; 52 | let body = &input.block; 53 | let attrs = &input.attrs; 54 | let vis = &input.vis; 55 | 56 | if name != "main" { 57 | return TokenStream::from(quote_spanned! { name.span() => 58 | compile_error!("only the main function can be tagged with #[async_std::main]"), 59 | }); 60 | } 61 | 62 | if input.sig.asyncness.is_none() { 63 | return TokenStream::from(quote_spanned! { input.span() => 64 | compile_error!("the async keyword is missing from the function declaration"), 65 | }); 66 | } 67 | 68 | let result = quote! { 69 | #vis fn main() #ret { 70 | #(#attrs)* 71 | async fn main(#inputs) #ret { 72 | #body 73 | } 74 | 75 | async_std::task::block_on(async { 76 | main().await 77 | }) 78 | } 79 | 80 | }; 81 | 82 | result.into() 83 | } 84 | 85 | /// Enables an async test function. 86 | /// 87 | /// # Examples 88 | /// 89 | /// ```ignore 90 | /// #[async_std::test] 91 | /// async fn my_test() -> std::io::Result<()> { 92 | /// assert_eq!(2 * 2, 4); 93 | /// Ok(()) 94 | /// } 95 | /// ``` 96 | #[proc_macro_attribute] 97 | pub fn test(_attr: TokenStream, item: TokenStream) -> TokenStream { 98 | let input = syn::parse_macro_input!(item as syn::ItemFn); 99 | 100 | let ret = &input.sig.output; 101 | let name = &input.sig.ident; 102 | let body = &input.block; 103 | let attrs = &input.attrs; 104 | let vis = &input.vis; 105 | 106 | if input.sig.asyncness.is_none() { 107 | return TokenStream::from(quote_spanned! { input.span() => 108 | compile_error!("the async keyword is missing from the function declaration"), 109 | }); 110 | } 111 | 112 | let result = quote! { 113 | #[::core::prelude::v1::test] 114 | #(#attrs)* 115 | #vis fn #name() #ret { 116 | async_std::task::block_on(async { #body }) 117 | } 118 | }; 119 | 120 | result.into() 121 | } 122 | 123 | /// Enables an async benchmark function. 124 | /// 125 | /// # Examples 126 | /// 127 | /// ```ignore 128 | /// #![feature(test)] 129 | /// extern crate test; 130 | /// 131 | /// #[async_std::bench] 132 | /// async fn bench_1(b: &mut test::Bencher) { 133 | /// b.iter(|| { 134 | /// println!("hello world"); 135 | /// }) 136 | /// } 137 | /// ``` 138 | #[proc_macro_attribute] 139 | pub fn bench(_attr: TokenStream, item: TokenStream) -> TokenStream { 140 | let input = syn::parse_macro_input!(item as syn::ItemFn); 141 | 142 | let ret = &input.sig.output; 143 | let args = &input.sig.inputs; 144 | let name = &input.sig.ident; 145 | let body = &input.block; 146 | let attrs = &input.attrs; 147 | let vis = &input.vis; 148 | 149 | if input.sig.asyncness.is_none() { 150 | return TokenStream::from(quote_spanned! { input.span() => 151 | compile_error!("the async keyword is missing from the function declaration"), 152 | }); 153 | } 154 | 155 | if !args.is_empty() { 156 | return TokenStream::from(quote_spanned! { args.span() => 157 | compile_error!("async benchmarks don't take any arguments"), 158 | }); 159 | } 160 | 161 | let result = quote! { 162 | #[::core::prelude::v1::bench] 163 | #(#attrs)* 164 | #vis fn #name(b: &mut test::Bencher) #ret { 165 | task::block_on(task::spawn(async { 166 | #body 167 | })) 168 | } 169 | }; 170 | 171 | result.into() 172 | } 173 | -------------------------------------------------------------------------------- /LICENSE-APACHE: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. 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