8 releases
Uses old Rust 2015
0.2.5 | Jul 26, 2017 |
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0.2.4 | Jul 26, 2017 |
0.1.1 | Jul 25, 2017 |
#2670 in Rust patterns
10KB
77 lines
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 theIfNoMatch
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.