scan_rules::try_readln! [−] [src]

macro_rules! try_readln {
    ($($rules:tt)*) => { ... };
}

Reads a line of text from standard input, then scans it using the provided rules. The result of the try_readln! invocation is a Result<T, ScanError>, where T is the type of the rule bodies; just as with match, all bodies must agree on their result type.