Lua vs Xtend

One of the best features of Lua is its very well designed C API. This is very useful if you have an existing C library you need to integrate with Lua or quickly get a Lua script running on the C side of the game.

Finally Lua plays so nice with C that if you need to optimise for speed you can re-write it in C a lot easier than other languages.

The official Lua documentation is very helpful and thorough. There are also a large number of online resources or books with lots of helpful information for beginners and advanced users alike.

Lua can be built on any platform with a ANSI C compiler.

Other than that, Lua is extremely small. For example, the tarball for Lua 5.2.1 is only 245K compressed and 960K uncompressed (including documentation).

When built on Linux, the Lua interpreter built with the standard libraries takes 182K and the Lua library takes 243K.

The small size and the ability to build with a C compiler make Lua an extremely portable language that can run on a lot of different systems and computers.

Easy to learn.

Lua's performance compares very well to other languages, If performance needs to be further improved you can:

1. Implement critical parts in C
2. Use the LuaJIT compiler. The LuaJIT compiler is a drop in replacement for the stock compiler and provides significant performance improvements. From the overview page:

LuaJIT speeds can rival code written in C.

Many different game engines (e.g. Elder Scrolls series, ToME) use Lua for scripting, and it's runtime is designed for embedded use.

The Lua syntax is modeled from Modula, a language known for being a fantastic introduction to programming.

The Lua syntax also has the following key characteristics:

• Semicolon as a statement separator is optional (mostly used to resolve ambiguous cases as in a = f; (g).x(a)).
• Syntactic sugar for function calls (f'string', f"string", f[[string]], and f{table}) and method calls (obj:m()).

Due to the growing popularity, Lua has a rather large and helpful community surrounding it.

Lambdas are written like Smalltalk's blocks. If it's the last argument, it can go after the parentheses like Ruby's blocks. Parentheses on method calls are optional.

It uses Java's static type system, but you don't have to declare the type of everything all the time, since the Xtend compiler can usually figure it out. This also dramatically cuts down on Java's infamous verbosity.

Because Xtend relies heavily on JDK and Android classes, it runs just as fast as native Java code.

Xtend is a low-risk option. Because it compiles to human-readable Java, if you decide you don't like it for your project, you can just switch back to Java without losing your work.

This is where it gets its name. You can open classes and add new methods, kind of like Ruby. (Of course this has to be compiled to Java, so really it lives in a kind of helper class.)

Uses functional features ,which are very concise and idiomatic. Plus it has annotations, which cuts down on the Java boilerplate.

Methods are public if you don't specify, and fields are private. Locals declared with val in Xtend are final in Java. This dramatically cuts down on Java's infamous verbosity.