collapsible_match

Default: Enabled

Source Code

What it does

Checks for nested match statements that can be collapsed into a single match statement. Note that this lint is not intended to find all cases where nested match patterns can be merged, but only cases where merging would most likely make the code more readable.

Example

fn func(opt: Option<Result<u32, felt252>>) {
    let n = match opt {
        Some(n) => match n {
            Ok(n) => n,
            _ => return,
        }
        None => return,
    };
}

Can be collapsed to

fn func(opt: Option<Result<u32, felt252>>) {
    let n = match opt {
        Some(Ok(n)) => n,
        _ => return,
    };
}