Macro scan

macro_rules! scan {
    ($input:expr;
        $(($($patterns:tt)*) => $bodies:expr),+
    ) => { ... };
    ($input:expr;
        ($($head_pattern:tt)*) => $head_body:expr
        , $(($($tail_patterns:tt)*) => $tail_bodies:expr,)*
    ) => { ... };
}

Scans the provided input, using the specified rules. The result 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.

The input may be any value which implements IntoScanCursor, which includes &str, String, and Cow<str>.

See also: Pattern Syntax.