47 lines
1.2 KiB
Zig
47 lines
1.2 KiB
Zig
//
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// Believe it or not, sometimes things go wrong in programs.
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//
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// In Zig, an error is a value. Errors are named so we can identify
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// things that can go wrong. Errors are created in "error sets", which
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// are just a collection of named errors.
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//
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// We have the start of an error set, but we're missing the condition
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// "TooSmall". Please add it where needed!
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const MyNumberError = error{
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TooBig,
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TooSmall,
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TooFour,
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};
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const std = @import("std");
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pub fn main() void {
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var nums = [_]u8{ 2, 3, 4, 5, 6 };
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for (nums) |n| {
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std.debug.print("{}", .{n});
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const number_error = numberFail(n);
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if (number_error == MyNumberError.TooBig) {
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std.debug.print(">4. ", .{});
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}
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if (number_error == MyNumberError.TooSmall) {
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std.debug.print("<4. ", .{});
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}
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if (number_error == MyNumberError.TooFour) {
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std.debug.print("=4. ", .{});
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}
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}
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std.debug.print("\n", .{});
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}
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// Notice how this function can return any member of the MyNumberError
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// error set.
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fn numberFail(n: u8) MyNumberError {
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if (n > 4) return MyNumberError.TooBig;
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if (n < 4) return MyNumberError.TooSmall; // <---- this one is free!
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return MyNumberError.TooFour;
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}
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