31 lines
864 B
Zig
31 lines
864 B
Zig
|
//
|
||
|
|
// A common case for errors is a situation where we're expecting to
|
||
|
|
// have a value OR something has gone wrong. Take this example:
|
||
|
|
//
|
||
|
|
// var text: Text = getText('foo.txt');
|
||
|
|
//
|
||
|
|
// What happens if getText() can't find 'foo.txt'? How do we express
|
||
|
|
// this in Zig?
|
||
|
|
//
|
||
|
|
// Zig let's us make what's called an "error union" which is a value
|
||
|
|
// which could either be a regular value OR an error from a set:
|
||
|
|
//
|
||
|
|
// var text: MyErrorSet!Text = getText('foo.txt');
|
||
|
|
//
|
||
|
|
// For now, let's just see if we can try making an error union!
|
||
|
|
//
|
||
|
|
const std = @import("std");
|
||
|
|
|
||
|
|
const MyNumberError = error{ TooSmall };
|
||
|
|
|
||
|
|
pub fn main() void {
|
||
|
|
var my_number: ??? = 5;
|
||
|
|
|
||
|
|
// Looks like my_number will need to either store a number OR
|
||
|
|
// an error. Can you set the type correctly above?
|
||
|
|
my_number = MyNumberError.TooSmall;
|
||
|
|
|
||
|
|
std.debug.print("I compiled!", .{});
|
||
|
|
}
|
||
|
|
|