Why embed lua into a game engine?

Question

I've been looking into building a basic game engine from the ground up and after making a list of features that are common to other engines, one of the bigger things is the fact that they have an embedded scripting language like lua or python.

My question is how is an embedded scripting language superior to just making a header file (or something of the like) that the user can include in a c++ file which gives them access to many of the functions and states. I'm sure there's a very good answer out there, I just haven't stumbled on it yet.

Also beyond why it's needed, what are languages like lua used for in things like game engines?

Answer 1

Lua is a far simpler language than C++, and all you need to edit it is a text editor. This puts the ability to script events and/or high level game logic in the hand of your designers and end users. Dynamic typing and garbage collecting allows them write very succinct code that focusses on game logic rather than all the systems-level housekeeping chores you get in a language like C++. It's also far easier to sandbox.

Lua is a popular choice because it's small, portable, hackable ANSI C code base; easy to embed, extend, and -- most importantly for game developers -- it has a minimal runtime footprint (one of the fastest interpreted languages). It's also a great combination of easy to learn/read/write syntax, but with powerful features like coroutines which can be very useful in games.