everybody_loops

A Replacement for the -Z unpretty=everybody_loops pass to rustc.

Usage

Take a file with a lot of functions, you want to get rid of them.

fn main() {
    let x = 1;
    let y = 2;
    let z = x + y;
}
struct Foo;

impl std::fmt::Debug for Foo {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
        write!(f, "Foo")
    }
}

impl Foo {
    fn boo(&self) {
        println!("boo");
    }
}

const f: () = {
    fn noop() {
        let x = 8;
    }
}

Just run

everybody_loops file.rs

And now you have a with much simpler code.

fn main() {
    loop {}
}
struct Foo;
impl std::fmt::Debug for Foo {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
        loop {}
    }
}
impl Foo {
    fn boo(&self) {
        loop {}
    }
}
const f: () = {
    fn noop() {
        loop {}
    }
};

Installation

cargo install --locked everybody_loops

Limitations

This will not work for functions with impl Trait in the return type, as the compiller needs to ascribe a concreat type.

Prior Art

• This used to be a compiller feature, but it was removed in #93913
• This post by Felix S Klock II first inroduced me to this technique.
• The code is a thin wrapper over syn and prettyplease, both by dtolnay, who diserves far more credit than me for making this happen.

License