..
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64 | //
// Enums are really just a set of numbers. You can leave the
// numbering up to the compiler, or you can assign them
// explicitly. You can even specify the numeric type used.
//
// const Stuff = enum(u8){ foo = 16 };
//
// You can get the integer out with a builtin function,
// @intFromEnum(). We'll learn about builtins properly in a later
// exercise.
//
// const my_stuff: u8 = @intFromEnum(Stuff.foo);
//
// Note how that built-in function starts with "@" just like the
// @import() function we've been using.
//
const std = @import("std");
// Zig lets us write integers in hexadecimal format:
//
// 0xf (is the value 15 in hex)
//
// Web browsers let us specify colors using a hexadecimal
// number where each byte represents the brightness of the
// Red, Green, or Blue component (RGB) where two hex digits
// are one byte with a value range of 0-255:
//
// #RRGGBB
//
// Please define and use a pure blue value Color:
const Color = enum(u32) {
red = 0xff0000,
green = 0x00ff00,
blue = ???,
};
pub fn main() void {
// Remember Zig's multi-line strings? Here they are again.
// Also, check out this cool format string:
//
// {x:0>6}
// ^
// x type ('x' is lower-case hexadecimal)
// : separator (needed for format syntax)
// 0 padding character (default is ' ')
// > alignment ('>' aligns right)
// 6 width (use padding to force width)
//
// Please add this formatting to the blue value.
// (Even better, experiment without it, or try parts of it
// to see what prints!)
std.debug.print(
\\<p>
\\ <span style="color: #{x:0>6}">Red</span>
\\ <span style="color: #{x:0>6}">Green</span>
\\ <span style="color: #{}">Blue</span>
\\</p>
\\
, .{
@intFromEnum(Color.red),
@intFromEnum(Color.green),
@intFromEnum(???), // Oops! We're missing something!
});
}
|
|
