ziglings/exercises/032_unreachable.zig
Dave Gauer 0956f1839f "999 is enough for anybody" triple-zero padding (#18)
When I hit 999 exercises, I will finally have reached the ultimate
state of soteriological release and no more exercises will be needed.
The cycle will be complete. All that will be left is perfect quietude,
freedom, and highest happiness.
2021-03-12 18:59:46 -05:00

44 lines
1.1 KiB
Zig

//
// Zig has an "unreachable" statement. Use it when you want to tell the
// compiler that a branch of code should never be executed and that the
// mere act of reaching it is an error.
//
// if (true) {
// ...
// } else {
// unreachable;
// }
//
// Here we've made a little virtual machine that performs mathematical
// operations on a single numeric value. It looks great but there's one
// little problem: the switch statement doesn't cover every possible
// value of a u8 number!
//
// WE know there are only three operations but Zig doesn't. Use the
// unreachable statement to make the switch complete. Or ELSE. :-)
//
const std = @import("std");
pub fn main() void {
const operations = [_]u8{ 1, 1, 1, 3, 2, 2 };
var current_value: u32 = 0;
for (operations) |op| {
switch (op) {
1 => {
current_value += 1;
},
2 => {
current_value -= 1;
},
3 => {
current_value *= current_value;
},
}
std.debug.print("{} ", .{current_value});
}
std.debug.print("\n", .{});
}