From 55ad7c32f2d534b1fbd438204d21738f958c51a5 Mon Sep 17 00:00:00 2001 From: Dave Gauer Date: Tue, 9 Feb 2021 18:36:57 -0500 Subject: Moved exercises to exercises because exercises --- exercises/35_enums.zig | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 exercises/35_enums.zig (limited to 'exercises/35_enums.zig') diff --git a/exercises/35_enums.zig b/exercises/35_enums.zig new file mode 100644 index 0000000..cf455a4 --- /dev/null +++ b/exercises/35_enums.zig @@ -0,0 +1,49 @@ +// +// Remember that little mathematical virtual machine we made using the +// "unreachable" statement? Well, there were two problems with the +// way we were using op codes: +// +// 1. Having to remember op codes by number is no good. +// 2. We had to use "unreachable" because Zig had no way of knowing +// how many valid op codes there were. +// +// An "enum" is a Zig construct that lets you give names to numeric +// values and store them in a set. They look a lot like error sets: +// +// const Fruit = enum{ apple, pear, orange }; +// +// const my_fruit = Fruit.apple; +// +// Let's use an enum in place of the numbers we were using in the +// previous version! +// +const std = @import("std"); + +// Please complete the enum! +const Ops = enum{ ??? }; + +pub fn main() void { + const operations = [_]Ops{ + Ops.inc, + Ops.inc, + Ops.inc, + Ops.pow, + Ops.dec, + Ops.dec + }; + + var current_value: u32 = 0; + + for (operations) |op| { + switch (op) { + Ops.inc => { current_value += 1; }, + Ops.dec => { current_value -= 1; }, + Ops.pow => { current_value *= current_value; }, + // No "else" needed! Why is that? + } + + std.debug.print("{} ", .{current_value}); + } + + std.debug.print("\n", .{}); +} -- cgit v1.2.3-ZIG