Lua VM running in Javascript (using emscripten)
Run emmake make && emmake make install then you have the compiled files in the dist folder.
LuaJS.addEventListener("ready", () => {
const L = new LuaJS.State();
let value;
value = L.run("return 1+2"); //value == [3]
value = L.run("return {a = 1, b = 2}"); //value[0] instanceof LuaJS.Table, value[0] instanceof LuaJS.Reference
value[0].get("a"); // == 1
console.log(value);
console.log(value[0].toObject(true, true)); //converts LuaJS.Table to JavaScript object (will drop all other LuaJS.Reference-s if unrefAll == true)
value[0].unref();
let func = L.run("return function(a,b) return a + b end"); //func[0] instanceof LuaJS.Function, func[0] instanceof LuaJS.Reference
value = func[0].call(3,4); //value == [7]
console.log(value);
func[0].unref();
});Using .unref() is optional as LuaJS does utilize Finalizers. However, those can be called at any time, so if you are memory constrained, manual unref might help!
Lua knows the library js, where the js.global table equals the JavaScript window object
When you call JS functions from Lua, the function parameters will always be automatically converted to JS equivalents (and internally .unref()'d, except functions).
You can convert JS objects/arrays to native Lua tables by using jsObject:toTable(recursive), however you can also directly index JS objects from Lua.
Warning: You need to call all JS functions either like js.global:alert("testmessage") or local alert = js.global.alert; alert(nil, "testmessage"). The first argument will be used as the "this" context in JavaScript.
If you call enableLuaScriptTags(document), you can specify <script type="text/lua"> tags just like JavaScript tags with either inline scripts or a src attribute.
Below is an example HTML document that enables Lua scripts for the entire page:
<!DOCTYPE html>
<html>
<head>
<script type="text/javascript" src="luajs.js"></script>
<script type="text/javascript">
LuaJS.addEventListener("ready", () => {
const L = new LuaJS.State();
L.enableLuaScriptTags(document);
});
</script>
<script type="text/lua">
js.global.console:log("Hello world")
</script>
</head>
</html>