cond
Rust macro to use a match-like syntax as an elegant alternative to many if-else statements.
I got the idea from empty Go switch statements. I thought it could be cool if it was in Rust so I asked if that was possible in the Rust community Discord server. They told me it wasn't unless you used a pretty ugly syntax in a match, and Esper89 (GitHub in credits) made a macro for it. I added some tests and documentation and here's my first Rust crate.
Example
use cond::cond;
fn main() {
let a = 195;
cond! {
a < 5 => println!("a is less than 5"),
a == 195 => {
println!("this is the way")
},
a > 10 => println!("a is greater than 10"),
// The conditions are executed by order: if one condition is true, conditions below will not get evaluated
};
let b = "";
let result = cond! { // Or use it as a block to return a value
b == "something" => false,
b.chars().count() > 10 => true,
a < 10000 => true,
_ => false // You must add a default with the return type if you want to return
};
println!("result: {}", result);
}
Usage
You can just add the crate with:
cargo add cond
Or just add the 8 line macro to your project:
macro_rules! cond {
($($condition:expr => $value:expr),* $(, _ => $default:expr)? $(,)?) => {
match () {
$(() if $condition => $value,)*
() => ($($default)?),
}
};
}
Credits
Credits to Esper89 for essentially making the whole macro in the Rust community Discord server.
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