Entry point

Contents

How a Program becomes Zig, in parts. Start with the introduction, then follow each part into the rendered output and the runtime it links against.

• Introduction — what the Zig target is, and how to read the rest of this section.
• Capabilities — which high-level features are possible, built in or through a library.
• Example — a full program using every keyword, and the Zig it renders to.
• Naming considerations — how Program's dotted names are carried into Zig.
• Entry point — starting a program from main with its drivers.
• Drivers — the native drivers that provide the interface, console and network.
• Runtime — the Reactive and Context machinery the rendered code links against.
• Native modules — the hand-written Zig behind NATIVE functions.
• Keywords — how each of Program's keywords renders to Zig.
• Project setup — the files and commands to build and run the rendered program.
• Reserved words — the words Zig keeps for itself, and how a colliding name is escaped.

Started from main

A Zig program starts from main. It registers the drivers it uses and runs the reactive program built from the root component. Because Zig has no closures, the root component is a named struct function.

pub fn main() !void {
    Program.application(struct { pub fn run() void {
        counter();
    } }.run, &.{ console.driver() });
}

Zig suits low-level, allocation-explicit native code; the interface driver renders to a terminal. Otherwise the model is exactly the JavaScript entry point — a root component, a driver list, and a loop that turns only when a value is written.