[vardump]

Last I checked Javascript implementations were slower than LuaJIT. Cost of implementing Lua tables, meta-tables, co-routines, etc. in Javascript will be rather high. Anywhere between 2-50x. If native Lua engine is removed, you can just forget about it then.

So what you're saying doesn't make any sense for anything remotely performance sensitive.

[striking]

It's a joke. Like haha, but serious, because some people actually believe this.

[bryanlarsen]

lua compiled to asm.js is 64% of the speed of lua native

https://kripken.github.io/lua.vm.js/lua.vm.js.html

[pygy_]

... which is about 10 times slower than the LuaJIT compiler used by OpenResty.

[Touche]

So that might be good enough in the browser but on the server where an optimized Lua engine exists, why?

[daurnimator]

That's not compiling lua to asm.js; it's running the lua vm in asm.js.

A straight up transpilation is other projects like lua.js. But you loose really nice core lua features like coroutines...

[kybernetikos]

> Cost of implementing Lua tables, meta-tables

Tables and meta tables are nearly identical to objects and prototypes in javascript. Why would the cost of implementing them be high?

[fanf2]

JavaScript objects are indexed by strings. Lua tables are indexed by arbitrary objects. In JS a[1] and a["1"] are the same element but they are different in Lua. In Lua a[{}] is a new element indexed by the identity of the new object literal, and will be a different element every time the expression is evaluated.