Re: What languages could be used to implement the functions to be invoked by Lua?

[Francisco Olarte <folarte@...>]

On Fri, Sep 18, 2020 at 10:59 AM 孙世龙 sunshilong <sunshilong369@gmail.com> wrote:
> As per the documentation(https://www.lua.org/pil/24.html), which says
> that[emphasise mine]:
> At the same time, a program that uses Lua can register new functions
> in the Lua environment;
> such functions are implemented in C (or **another language**) and can
> add facilities that
> cannot be written directly in Lua.
> My question is what other languages?
> Can these functions be implemented in C++? If not, is there any
> workaround to achieve this goal?
> If you could give some simple examples, that would be great.

Once compiled, everything is machine code. You only have to worry
about the calling convention ( where are parameters passed and how are
values returned ). Also, Lua uses some C-oriented data ( like null
terminated strings ), so your language must be able to manage them,
but nearly every language can.

Regarding C++, I do all my modules using it. I embed the modules and
do not use dynamic loading, so I do not care about naming ( but using
extern "C" you can easily do it. I just use static functions in my
clases ( I register a static function in lua, this function gets the
object pointer, if needed, and calls a normal method, so I can keep
everyting private if I like to ).

Any language which can call C would do. If your language as bindings
for any of the popular libraries, be it xml, graphics, sound, whatever
chances are it can call ( to use the api functions ) and be called by
( to register extensions )  lua without problem.

Francisco Olarte.