add comptime

Author: ziteh

comptime/expression.zig

@@ -0,0 +1,31 @@
+const print = @import("std").debug.print;
+const now = @import("std").time.nanoTimestamp;
+
+fn fibonacci(index: u64) u64 {
+    if (index < 2) return index;
+    return fibonacci(index - 1) + fibonacci(index - 2);
+}
+
+fn run() void {
+    const number = 25;
+
+    // Run-time
+    const start1 = now();
+    const res1 = fibonacci(number);
+    const end1 = now();
+
+    // Compile-time
+    const start2 = now();
+    const res2 = comptime fibonacci(number);
+    const end2 = now();
+
+    print("Run-time:     {d} in {}ns\n", .{ res1, end1 - start1 });
+    print("Compile-time: {d} in {}ns\n", .{ res2, end2 - start2 });
+    print("\n", .{});
+}
+
+pub fn main() void {
+    for (1..6) |_| {
+        run();
+    }
+}

comptime/generics.zig

@@ -0,0 +1,13 @@
+const print = @import("std").debug.print;
+
+fn add(comptime T: type, a: T, b: T) T {
+    return a + b;
+}
+
+pub fn main() void {
+    const res1 = add(u8, 5, 10);
+    const res2 = add(f32, 100, -10);
+
+    print("Result 1: {d}\n", .{res1});
+    print("Result 2: {d}\n", .{res2});
+}

comptime/readme.md

@@ -0,0 +1,25 @@
+# Comptime
+
+```bash
+$ zig run generics.zig
+Result 1: 15
+Result 2: 90
+```
+
+```bash
+$ zig run expression.zig
+Run-time:     75025 in 1003800ns
+Compile-time: 75025 in 0ns
+
+Run-time:     75025 in 996000ns
+Compile-time: 75025 in 0ns
+
+Run-time:     75025 in 998600ns
+Compile-time: 75025 in 0ns
+
+Run-time:     75025 in 1000200ns
+Compile-time: 75025 in 0ns
+
+Run-time:     75025 in 1505500ns
+Compile-time: 75025 in 0ns
+```