Ecosyste.ms: Awesome
An open API service indexing awesome lists of open source software.
https://github.com/regexident/apply_attr
A syntax extension providing higher-order attributes to Rust.
https://github.com/regexident/apply_attr
compiler-plugin metaprogramming rust
Last synced: about 2 months ago
JSON representation
A syntax extension providing higher-order attributes to Rust.
- Host: GitHub
- URL: https://github.com/regexident/apply_attr
- Owner: regexident
- License: mpl-2.0
- Created: 2016-05-17T12:39:49.000Z (over 8 years ago)
- Default Branch: master
- Last Pushed: 2017-12-03T16:38:51.000Z (about 7 years ago)
- Last Synced: 2024-10-06T20:17:10.986Z (3 months ago)
- Topics: compiler-plugin, metaprogramming, rust
- Language: Rust
- Size: 938 KB
- Stars: 16
- Watchers: 4
- Forks: 2
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- Contributing: CONTRIBUTING.md
- License: LICENSE.md
Awesome Lists containing this project
README
# apply_attr
[](https://travis-ci.org/regexident/apply_attr)
[](https://crates.io/crates/apply_attr/)
[](https://crates.io/crates/apply_attr/)
[](https://crates.io/crates/apply_attr/)
## Synopsis
A syntax extension providing higher-order attributes to Rust.
## Motivation
Sometimes it would be desirable to be able to apply certain attributes to all items in a scope (`mod`, `trait` or `impl`). The **`apply_attr`** crate aims to provide a versatile API for this.
Possible use-cases would be:
- Make all structs in mod `xyz` use `#[derive(PartialEq)]`.
- Mark all methods in a certain `impl` with `#[inline(never)]` (for profiling, e.g.).
- …
## Getting Started
Add the most recent [version](https://crates.io/crates/apply_attr) of `apply_attr`
to your dependencies in your project's `Cargo.toml`.
Then add …
```rust
#![feature(custom_attribute)]
#![feature(plugin)]
#![plugin(apply_attr)]
```
… to your crate's root file (e.g. `lib.rs`, `main.rs`).
Once that's done you're ready to play!
# Example
```rust
#![feature(custom_attribute)]
#![feature(plugin)]
#![plugin(apply_attr)]
// Make all top-level structs as well as those
// within top-level mods implement `PartialEq`:
#![apply_attr(to(structs, mods(structs)), as_default(derive(PartialEq)))]
pub struct Foo;
mod Bar {
pub struct Baz;
// ...
}
// Disable inlining when `no_inline` feature is present:
#[cfg_attr(feature = "no_inline", apply_attr(to(fns), as_override(inline(never))))]
impl Blee {
fn foo(&self) { ... }
fn bar(&self) { ... }
fn baz(&self) { ... }
fn blee(&self) { ... }
}
fn main() {
Foo == Foo;
Bar::Baz == Bar::Baz;
}
```
## API Reference
The `apply_attr` syntax extension provides a single higher-order attribute,
conveniently named `apply_attr` expecting two arguments:
1. `to(...)` (with `...` being a list of zero or more selectors).
2. `as_default(...)` or `as_override(...)` (with `...` being a list of zero or more attributes).
Resulting either of:
```rust
#[apply_attr(to(...), as_default(...))]
#[apply_attr(to(...), as_override(...))]
```
The first argument (`to(...)`) accepts a nested list of item selectors.
## Selectors
Selectors behave similar to CSS selectors:
As such a CSS selector like `div > span, p` would translate to `to(div(span), p)`.
### Flat Selectors
The following selectors are supported:
```rust
consts
crates
def_impls
enums
fgn_mods
fns
impls
macros
mods
statics
structs
traits
types
uses
```
### Nested Selectors
With the following ones allowing for nesting:
```rust
mods(...)
impls(...)
traits(...)
```
Nested selectors denote direct ancestry equivalent to CSS's `outer > inner` path operator.
## Attributes
### Default
Attributes can either be applied as using `as_default(...)`, in which case …
```rust
#[apply_attr(to(fns), as_default(inline(never)))]
impl Foo {
#[inline(always)]
fn foo() { ... }
}
```
… will be turned into …
```rust
impl Foo {
#[inline(always)]
fn foo() { ... }
}
```
… upon completion.
### Overriding
Or using `as_override(...)`, in which case …
```rust
#[apply_attr(to(fns), as_override(inline(never)))]
impl Foo {
#[inline(always)]
fn foo() { ... }
}
```
… will be turned into …
```rust
impl Foo {
#[inline(never)]
fn foo() { ... }
}
```
… upon completion.
## Debugging
To see how the attributes were applied compile your crate using this (requires `nightly`):
```bash
cargo rustc -- -Z unstable-options --pretty=expanded
```
## Contributing
Please read [CONTRIBUTING.md](CONTRIBUTING.md) for details on our [code of conduct](https://www.rust-lang.org/conduct.html),
and the process for submitting pull requests to us.
## Versioning
We use [SemVer](http://semver.org/) for versioning. For the versions available, see the [tags on this repository](https://github.com/regexident/apply_attr/tags).
## Authors
* **Vincent Esche** – *Initial work* – [Regexident](https://github.com/Regexident)
See also the list of [contributors](https://github.com/regexident/apply_attr/contributors) who participated in this project.
## License
This project is licensed under the [**MPL-2.0**](https://www.tldrlegal.com/l/mpl-2.0) – see the [LICENSE.md](LICENSE.md) file for details.