match_all

Provides the match_all! macro for rust

This macro provides similar functionality to a vanilla match statement but allows for multiple expression blocks to be executed.

Format

match_all!{ value,
    IfNoMatch => expr,
    pat | pat ... => expr,
    ...
}

• value: the expression to match on.
• IfNoMatch: the expression after this is executed if none of the other patterns are matched. This branch is optional.
• pat | pat ...: this is groupings of patterns that will be checked. If any of them match to value then their corresponding expression is executed. After checking a group of patterns then the next group is checked until all groups have been checked. If none match then the IfNoMatch expression will be executed.

Example One

let value = Some(4);

match_all!{ value,
    None => println!("Hi"),
    Some(3) | Some(4) => println!("Hello"),
    Some(4) | Some(5) => println!("Howdy")
}

This would print:

Hello
Howdy

Example Two

let value = Some(20);
match_all!{ value,
    IfNoMatch => println!("No Match"),
    0...4 => println!("0 through 4")
};

This would print:

No Match

It prints this because it uses the special IfNoMatch expression to provide an expression that matches only when no other expression was matched.