Lua

[[deleted user]]

Lua is a language I not only have never programmed in, but never even heard of before this book! Yet, it appears to be very popular in certain application areas, such as video game programming (World of Warcraft in particular). It is imperative-functional-dynamic-scripting-minimal, and appears to use good ideas from a vast number of other languages. It was developed in Brazil in 1993.

This chapter reminds me that I have to really understand what a "closure" is someday.

I would be interested in knowing WHY this is a popular language for video games...

[Nathan]

It's becoming more common to use scripting languages for game development because the rules-aspect of the game ends up being tweaked quite a bit before (and often after) release. The dynamic nature of the scripting language makes this iterative process easier. Aside from the Lua cases, Civilization IV is a popular game that utilizes Python for this purpose.

Apple's recent decision to ban the use "an intermediary translation or compatibility layer" could have some consequences for developers who wish to use Lua to create games on the iPhone OS. Apple is positioning the iPod Touch as a gaming device, and they've been successful enough to convince Nintendo that Apple is the main competition now, so this could have real ramifications for game development in the mobile arena.

[[deleted user]]

Interesting, Nathan.. thanks.

[Erik]

The section about not requiring a CS degree was nice to read. A few years ago, I was on a team of five software engineers composed of 2 EEs, 1 MS Math from Notre Dame, 1 PhD in Bio-Chem from Princeton, and 1 MS Civil Engineering from Brazil. That team was a great example of non-CS backgrounds delivering extremely successful software.

They talked a lot about being ANSI C compliant. I don't understand at what point something becomes a new language or when something is just another library or language extension. Would a syntax that parses and compiles by mapping to C syntax be a new language or just a wrapper around C? Would that just be a "little language" or a meta-language?

[[deleted user]]

CS degrees are a "relatively" recent thing. The first one was granted by Purdue in 1962. Early in my career, most programmers were math or physics majors. Today, non-CS degree programmers are more a function of interest and job market.

As far as language vs. library, I would draw the line at Turing completeness. So, if it is possible to write all possible programs in the extension, it is a language. If not, it is a library.