gopher-lua VS otto

Would be neat to see graph of recent versions with linear scale

I checked, they use switch on opcodes in vm.go. So would expect a recent improvement, but probably only <5%, & I didn't look close enough to see if awk is one of those languages where instruction dispatch matters less (like how APL tends to avoid issues since array ops avoid having dispatch in tight loops, or how Python avoids instruction dispatch overhead when using numpy)

For VMs Go had a problem for large switch statements: it would always use binary search instead of a jump table. This caused gopher-lua & go-lua to both take the route of having an array of functions which they call on to dispatch instead

A couple years ago this was fixed: https://go-review.googlesource.com/c/go/+/357330

I measured a small perf improvement switching gopher-lua to switch: https://github.com/yuin/gopher-lua/pull/479

Not the parent but there are several high quality native (meaning no CGO) Lua implementations for Go and it's a great choice if you want an embedded scripting language:

https://github.com/yuin/gopher-lua

The "game" was just an example, what I'm exactly trying to do is creating a plugin system for my go app using gopher-lua. The thing is the app will be used by end users and I can't ask them to install libraries. ATM, I don't care about libs with external dependencies like openssl, zlib etc. supporting just the pure Lua ones is enough

I'm generally using Visual Studio Code for all my development. Really like it.

I chose https://github.com/yuin/gopher-lua as the Lua engine because it is Golang-based, while the Nginx Lua VM is C, unless I'm mistaken. Using gopher-lua is just easier when I'm working in a Golang project. I only have to work in a single language and dev environment for all the backend work. Makes both development and testing easier.

Moonscript I might have heard of, but I have no experience with it. I did not consider it here, and I would rarely consider any niche scripting language for a solution I want others to use. It just introduces an unnecessary barrier to adoption.

GopherLua [0] is a Lua implementation written in Go, not just a wrapper around the C implementation.

The main alternative seems to be Shopify’s go-lua [1], given that Microsoft’s golua [2] is no longer being developed. The main difference between these three implementations seems to be the supported Lua version - 5.1, 5.2 and 5.3 respectively.

[0] https://github.com/yuin/gopher-lua

[1] https://github.com/Shopify/go-lua

[2] https://github.com/Azure/golua

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.