"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.

1 files changed, 55 insertions, 0 deletions

diff --git a/exercises/035_enums.zig b/exercises/035_enums.zig
new file mode 100644
index 0000000..1825f52
--- /dev/null
+++ b/exercises/035_enums.zig
@@ -0,0 +1,55 @@
+//
+// 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", .{});
+}