denoland-rusty-v8/examples/hello_world.rs

fn main() {
  // Initialize V8.
  let platform = v8::new_default_platform(0, false).make_shared();
  v8::V8::initialize_platform(platform);
  v8::V8::initialize();

  {
    // Create a new Isolate and make it the current one.
    let isolate = &mut v8::Isolate::new(v8::CreateParams::default());

    // Create a stack-allocated handle scope.
    let handle_scope = &mut v8::HandleScope::new(isolate);

    // Create a new context.
    let context = v8::Context::new(handle_scope);

    // Enter the context for compiling and running the hello world script.
    let scope = &mut v8::ContextScope::new(handle_scope, context);

    // Create a string containing the JavaScript source code.
    let code = v8::String::new(scope, "'Hello' + ' World!'").unwrap();

    // Compile the source code.
    let script = v8::Script::compile(scope, code, None).unwrap();
    // Run the script to get the result.
    let result = script.run(scope).unwrap();

    // Convert the result to a string and print it.
    let result = result.to_string(scope).unwrap();
    println!("{}", result.to_rust_string_lossy(scope));

    // Use the JavaScript API to generate a WebAssembly module.
    //
    // |bytes| contains the binary format for the following module:
    //
    //     (func (export "add") (param i32 i32) (result i32)
    //       get_local 0
    //       get_local 1
    //       i32.add)
    //
    let c_source = r#"
          let bytes = new Uint8Array([
            0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00, 0x01, 0x07, 0x01,
            0x60, 0x02, 0x7f, 0x7f, 0x01, 0x7f, 0x03, 0x02, 0x01, 0x00, 0x07,
            0x07, 0x01, 0x03, 0x61, 0x64, 0x64, 0x00, 0x00, 0x0a, 0x09, 0x01,
            0x07, 0x00, 0x20, 0x00, 0x20, 0x01, 0x6a, 0x0b
          ]);
          let module = new WebAssembly.Module(bytes);
          let instance = new WebAssembly.Instance(module);
          instance.exports.add(3, 4);
        "#;
    // Create a string containing the JavaScript source code.
    let source = v8::String::new(scope, c_source).unwrap();

    // Compile the source code.
    let script = v8::Script::compile(scope, source, None).unwrap();

    // Run the script to get the result.
    let result = script.run(scope).unwrap();

    // Print the result.
    let result = result.to_uint32(scope).unwrap();
    println!("3 + 4 = {}", result.value());
  }

  unsafe {
    v8::V8::dispose();
  }
  v8::V8::dispose_platform();
}