Macro loop_unwrap::unwrap_continue

macro_rules! unwrap_continue {
    ($x:expr) => { ... };
    ($x:expr, $label:lifetime) => { ... };
    ($x:expr, $label:lifetime, $err_msg:expr) => { ... };
    ($x:expr, $err_msg:expr) => { ... };
    ($x:expr, $err_msg:expr, $label:lifetime) => { ... };
}

Works like .unwrap, if it’s an Err or None, it calls continue on the loop. Prints an error message with println!() if provided. Loop Label can be provided in any order besides the Result/Option being the first argument. If loop label is proivded, the specified loop will be continued.

Examples

loop {
        let input = "Not a number";
        let parsed_input: i32 = unwrap_continue!(input.parse()); //parse returns Err for this input
        break; //<-- never reached, since `continue` is called.
    }

loop {
        let input = "Not a number";
        let parsed_input: i32 = unwrap_continue!(input.parse(), "Please Enter a Number!");
        // "Please Enter a Number!" is printed in console with a `println!()`
        break;
    }

loop {
        let some_value: i32 = unwrap_continue!(Some(32), "Please Enter a Number!");
        assert_eq!(some_value, 32_i32)
    }

'main: loop {
        loop {
            let n =
                unwrap_continue!("t".parse::<i32>(), "Couldn't parse, retrying main loop", 'main);
            break 'main; //<-- this line will never be reached, and main will go into an infinite loop
        }
        break; //<-- this line won't be reached, since 'main will be continued infinitely
    }