otto VS tengo

robertkrimen/otto

Ummm, excuse me, but where the f&$k has this been hiding? I’ve been looking for ways to extend my go applications with scripting support. I started with Lua (worked ) then Python (worked but hacky) then javascript using otto [1]. However it lacks ES6 support so having pretty OOP js code is a non-starter. I would love to have Java as a runtime that can be executed from goroutines.

[1] https://github.com/robertkrimen/otto

Either call a JavaScript interpreter like node with exec.Command and read its stdout, or use a pure Go JavaScript interpreter like goja or otto.

Otto https://github.com/robertkrimen/otto Seems interesting. It lets me call Go functions from inside JS as well as return results. The fncs pattern reminds me a bit of how the template engine works.

> why host other languages

Here's an example:

I recently finished building https://subzo.com.au which allows customizing and ordering 3D models. The way the model's cost, volume and other attributes are calculated needs to be done both on the frontend (for speed) and on the backend (to validate). Backend is in Go and we can't practically run Go in the browser. So instead, I wrote the calculation snippets in JavaScript (which runs natively in the browser) and ran them on the backend on a JavaScript VM library written in Go [1].

[1]: https://github.com/robertkrimen/otto

Googling suggests https://github.com/robertkrimen/otto which allows scripting in javascript for golang projects. This would be definitely enough, but in some way it may be a bit overkill - and scripts supporter shall need some knowledge of javascript which is not always straightforward :)

It doesn't make sense to ask the user (aka me) to change the code every time I want to modify any web apps right? So I decided to split the webapps into two parts. WebApps are those only require basic permissions and do not interact with the host OS. They will be run inside a sandbox created using ECMA5 VM called Otto. The other type is called Subservice, in which it will need extra permission to interact with the OS and require higher level of access to the backend file system.

> It also has a bunch of libraries for embedding scripting languages https://awesome-go.com/embeddable-scripting-languages, with Tengo _probably_ being the quickest https://github.com/d5/tengo

Yes, I noticed those packages recently. The problem is that there is little data about how reliable and maintainable goloader is going to be on the long term.

As I care about performance and security, I don't want a scripting language, but WASM seems to be a very promising possibility. I have made benchmarks with 2~3 WASM engines in Go, and so far I am not completely convinced about the quality and performance of the available APIs. Also, when compiling Golang to WASM, the native compiler is still abysmally bad and does not have full support for imports, so Tinygo is a must-have.

Anyway, modding is still a long term idea at this point, so hopefully the ecosystem will get more mature within a couple of years.

- https://github.com/d5/tengo

There are totally different things like https://github.com/d5/tengo but I don't know much about the docs, communities, or viability of them. Some like this one look very active and healthy. It might be worth considering.

I started doing this a few years ago when I wanted to add programmability to another system I was working on, and didn't want Lua or anything else like that. I set it aside when other priorities arose, and didn't return to it when I saw that others had already done the same thing (yaegi, tengo).