README.md

About

This is a tiny library lets you call the WebAssembly exported functions that are tweaked by wasmedge-bindgen.

Guide

Originally, you can call the wasm function from WasmEdge-go like this:

import (
	"github.com/second-state/WasmEdge-go/wasmedge"
)

func main() {
	vm := wasmedge.NewVM()
	vm.LoadWasmFile("say.wasm")
	vm.Validate()
	vm.Instantiate()
	vm.Execute("say")
}

When your wasm function is retouched by #[wasmedge_bindgen]:

#[wasmedge_bindgen]
pub fn say(s: String) -> String {
  let r = String::from("hello ");
  return r + s.as_str();
}

Then you should call it using this library:

import (
	"github.com/second-state/WasmEdge-go/wasmedge"
	bindgen "github.com/second-state/wasmedge-bindgen/host/go"
)

func main() {
	vm := wasmedge.NewVM()
	vm.LoadWasmFile("say.wasm")
	vm.Validate()

	// Instantiate the bindgen and vm
	bg := bindgen.Instantiate(vm)

	/// say: string -> string
	result, err := bg.Execute("say", "wasmedge-bindgen")
	if err == nil {
		fmt.Println("Run bindgen -- say:", result[0].(string))
	}
}

Explain

The result is an interface array ([]interface{}). Normally, the length of the array is 1. When the return value of wasm(rust) is (Tuple,) or Result<(Tuple,), String>, the array length will be the same with the members' count of tuple.

If the function returns Err(String), you will get it by err.