Lua and Merc

I want to integrate a scripting language into a Merc MUD. Research has led me here.

I wrote my own "mobprog" functionality back in 1999. It's, uh, not very good, and the effort was daunting enough that I've avoided re-addressing it, until now.

Judging by forum activity, it looks like I'm 3 or more years behind the curve. That sounds about right.

I know this has nothing to do with Merc (who runs Merc anymore anyway?!), but this forum seems to be the closest match for what I'm looking for.

Any words of wisdom before I embark on integrating Lua? I've been reading various threads, and the potential is very exciting. At the same time, I would like to avoid as much pain as possible.

Advice welcome!

Thank you.

Welcome to the Lua party! :P

Lua is remarkably easy to embed and quite hassle free. Avoiding pain should be pretty easy.

My suggestion would be to play with embedding Lua in some simple C/C++ progs before you attempt to integrate it into your game. Doing some simple examples (running scripts, calling C from Lua and Lua from C, etc) will help you make a few important design decisions. After you play with some examples I would suggest deciding on the scope of your implementation. It is much easier to implement it only for mobprogs compared to something like internal game logic. This is mostly due to the effort involved in exposing game data to the scripts. However, if you can somewhat gracefully expose a lot of your game data to scripts then you can build a much more dynamic game.

Nick Gammon wrote a very good post on simple examples of Lua embedding in C/C++. I'm sure you found it already, but here is the link in case you missed it:



And, of course, the heavy-weight thread detailing the addition to SMAUG will be useful:

Also:





Aardwolf uses a Lua interface these days for their scripting. It is completely different to what I describe here, but shows that they also agree that it is a good idea in principle to do. You could look at their "builders guide" on their web site to see how they went about it, at least from the interface point of view.

Thank you both for the replies and links. I appreciate it. So much useful detail.

Nick, you mentioned Aardwolf's Lua implementation and how it's completely different from what you have done. If you had it to do over again, would you design your Lua interface pretty much how you've done it, or more how Aardwolf designed it?

Thanks again for the reference implementation. I've never been exposed to Lua before, aside from skimming through the online book, so it helps to see how the code would be written in practice.

I haven't seen the implementation of Aardwolf (the source is not released) but from what I have seen of the documentation it is much more sophisticated than what I did.

My examples were more of a proof of concept, whereas Aardwolf is running live on an active MUD.