x := int64(300)
ptr := &x

import "encoding/json"
 
type Person struct {
    Name string   `json:"name"`
    Age  *int     `json:"age"` // age if known; nil otherwise
}
 
func personJSON(name string, born time.Time) ([]byte, error) {
    return json.Marshal(Person{
        Name: name,
        Age:  new(yearsSince(born)),
    })
}
 
func yearsSince(t time.Time) int {
    return int(time.Since(t).Hours() / (365.25 * 24)) // approximately
}

type Adder[A Adder[A]] interface {
    Add(A) A
}
 
func algo[A Adder[A]](x, y A) A {
    return x.Add(y)
}

//go:build tinygo
// +build tinygo
 
package main
 
[...]
 
func main() {
	js.Global().Set("trucoNew", js.FuncOf(trucoNew))
	js.Global().Set("trucoRunAction", js.FuncOf(trucoRunAction))
	js.Global().Set("trucoBotRunAction", js.FuncOf(trucoBotRunAction))
	select {}
}
 
var (
	state *truco.GameState // "Global variable" for the GameState
	bot   truco.Bot
)

func trucoRunAction(this js.Value, p []js.Value) interface{} { // Always this signature
	// Read the input JSON
    jsonBytes := make([]byte, p[0].Length()) 
	js.CopyBytesToGo(jsonBytes, p[0])
 
	// 1. Decode the input JSON to your struct
    // 2. Run your Go code, return an output struct
	// 3. Encode the output struct to JSON
	newBytes := _runAction(jsonBytes)
 
	// Return the output JSON
	buffer := js.Global().Get("Uint8Array").New(len(newBytes))
	js.CopyBytesToJS(buffer, newBytes)
	return buffer
}

function jsRunAction(data) {
    const encoder = new TextEncoder();
    const encodedData = encoder.encode(JSON.stringify(data));
    const result = trucoRunAction(encodedData);
    const json = new TextDecoder().decode(result);
    return JSON.parse(json);
}
 
let gameState = jsNewGame();
 
// Note that RunAction doesn't take a GameState.
// WASM is the source of truth; your frontend can't mutate it.
gameState = jsRunAction(action);

 
compile_library:
	cd $(GOPATH)/src/github.com/marianogappa/escoba && \
	TINYGOROOT=/usr/local/Cellar/tinygo/0.38.0 tinygo build -o main.wasm -target wasm main_wasm.go && \
	mv main.wasm $(CURDIR)/public/wasm/wasm.wasm && \
	cp /usr/local/Cellar/tinygo/0.38.0/targets/wasm_exec.js $(CURDIR)/public/wasm/wasm_exec.js && \
	cd -

 
    <script src="wasm/wasm_exec.js"></script>
	<script>
        const go = new Go(); // Defined in wasm_exec.js
        const WASM_URL = 'wasm/wasm.wasm';
 
        var wasm;
        let wasmReady = false;
 
        if ('instantiateStreaming' in WebAssembly) {
            WebAssembly.instantiateStreaming(fetch(WASM_URL), go.importObject).then(function (obj) {
                wasm = obj.instance;
                go.run(wasm);
                wasmReady = true;
            })
        } else {
            fetch(WASM_URL).then(resp =>
                resp.arrayBuffer()
            ).then(bytes =>
                WebAssembly.instantiate(bytes, go.importObject).then(function (obj) {
                    wasm = obj.instance;
                    go.run(wasm);
                    wasmReady = true;
                })
            )
        }
    </script>