Updated sample for Go 1.9

[koen92]

Hi,

Thank you for your example! It really helped me a lot to understand how to bind a Go lib to node-ffi.

However, your example was out of date for the current Go version (1.9). This PR fixes some issues that occur when running your example with the latest Go version.

[marcboeker]

@koen92 I've found a way to return a string without hitting the runtime error. Converting the string back to a CString results in a Buffer object on the JavaScript side:

//export Hi
func Hi(name string) *C.char {
	return C.CString(fmt.Sprintf("Hi %s", name))
}

Change the return type to string:

var hw = FFI.Library(hw_path, {
  Hi: ['string', [GoString]],
})

And convert the returned Buffer to a string:

var res = hw.Hi(NewGoString('John'))
console.log(res.toString())

[MrSaints]

Thanks for taking a crack at this @koen92.

I've updated the repository (see 98cf01d) to work with Go 1.9, and Node 7.9. I took a slightly different approach. It appears to work on my machine, but there is a chance it may not work on someone else's machine.

Basically, I opted to create a type that can handle the getting, and setting, without forcing the user to know about the internals / esoterics. It handles the GoString conversion on get, and on set.

@marcboeker may work, but I wanted to keep it simple, without having too much cognitive overhead from cgo knowledge.

Thanks again all.