Entry point

Contents

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

• Introduction — what the Rust target is, and how to read the rest of this section.
• Capabilities — which high-level features are possible, built in or through a crate.
• Example — a full program using every keyword, and the Rust it renders to.
• Naming considerations — how Program's dotted names are carried into Rust.
• 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 Rust behind NATIVE functions.
• Keywords — how each of Program's keywords renders to Rust.
• Project setup — the files and commands to build and run the rendered program.
• Reserved words — the words Rust keeps for itself, and how a colliding name is escaped.

Started from main

A Rust program starts from main. It registers the drivers it uses, builds the reactive program from the root component, and runs the loop until the program ends.

fn main() {
    Program::Application(Box::new(|| {
        Counter();
    }), vec![
        Console::Driver(),
    ]);
}

Rust suits systems and back-end 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.