Go Lua Compiler and VM

This is a Lua 5.3 VM and compiler written in Go. This is intended to allow easy embedding into Go programs, with minimal fuss and bother. It can also run in a browser by Webassembly.

This repository is forked from milochristiansen/lua, and I made some incompatible changes. So it's unlikely to be merged into the original repository.

The strftime function and string pattern matching is currently copied from yuin/gopher-lua. It may be rewritten in the future.

Usage

package main

import (
	"github.com/ofunc/lua/util"
)

func main() {
	l := util.NewState()
	util.Run(l, "main.lua")
}

local js = require 'js'
local window = js.global

window:setTimeout(function()
	window:alert('Hello world!')
end, 1000)

Please refer to the README for standard libraries.

Dependencies

• Go 1.12+

Modules

• ioc - Inversion of Control module for Lua.
• lmodbolt - boltdb/bolt bindings for Lua.
• lmodhttpclient - http.Client bindings for Lua.
• lmodmsgpack - MessagePack for Lua.
• lmodoffice - A simple Lua module for converting various office documents into OOXML format files.
• lmodxlsx - plandem/xlsx bindings for Lua.
• mithril - Mithril.js bindings for Lua.
• stream - A simple lazy list module for Lua.

Missing Stuff

The following standard functions are not available:

• collectgarbage (not possible, VM uses the Go collector)
• xpcall (VM has no concept of a message handler)
• next (I don't need it at this time)
• load (violates my security policy)
• dofile (violates my security policy, use require)
• loadfile (violates my security policy, use require)
• string.dump (violates my security policy)
• string.pack (I don't need it at this time, use msgpack)
• string.packsize (I don't need it at this time, use msgpack)
• string.unpack (I don't need it at this time, use msgpack)

---

The following standard modules are not available:

• package (violates my security policy, use util.AddPath)
• debug (violates my security policy)
• coroutine (no coroutine support yet, use goroutine)

---

The following modules are not implemented exactly as the Lua 5.3 specification requires:

• math.random (initialize the seed by default using program startup time)
• os (Go style functions)
• io (Go style functions)

---

There are a few things that are implemented exactly as the Lua 5.3 specification requires, where the reference Lua implementation does not follow the specification exactly:

• The # (length) operator always returns the number of positive integer keys. When the table is a sequence, it's exactly equal to the sequence's length.
• Modulo operator (%) is implemented the same way most languages implement it, not the way Lua does. This does not matter unless you are using negative operands.

---

The following core language features are not supported:

• Hexadecimal floating point literals are not supported at this time.
• Weak references of any kind are not supported. This is because the VM uses Go's garbage collector, and it does not support weak references.
• Finalizers are not supported.

TODO

• More tests.
• Better error hints.
• Code optimization.