Roberto Ierusalimschy - Programming in Lua, Third Edition

Lua users typically fall into three broad groups:those that use Lua already embedded in an application program,those that use Lua stand alone,and those that use Lua and C together.

Many people use Lua embedded in an application program,such as Adobe Lightroom, Nmap, or World of Warcraft.These applications use the LuaC APIto register new functions,to create new types,and to change the behavior of some language operations,configuring Lua for their specific domains.Frequently,the users of such applications do not even know thatLua is an independent language adapted for a particular domain.For instance,many developers of plug-ins for Lightroom do not knowabout other uses of the language;Nmap users tend to think of Lua as the languageof the Nmap Scripting Engine;players of World of Warcraftmay regard Lua as a language exclusive to that game.

Lua is useful also as a stand-alone language,not only for text-processing and one-shot little programs,but increasingly for medium-to-large projects, too.For such uses, the main functionality of Lua comes from libraries.The standard libraries, for instance,offer basic pattern matching andother functions for string handling.As Lua improves its support for libraries,there has been a proliferation of external packages.Lua Rocks,a deployment and management system for Lua modules,currently features more than 150 packages.

Finally, there are those programmers that work onthe other side of the bench,writing applications that use Lua as a C library.Those people will program more in C than in Lua,although they need a good understanding of Luato create interfaces that are simple,easy to use, and well integrated with the language.

This book has much to offer to all these people.The first part covers the language itself,showing how we can explore all its potential.We focus on different language constructsand use numerous examples and exercisesto show how to use them forpractical tasks.Some chapters in this part cover basic concepts,such as control structures,while others cover topics more advanced,such as iterators and coroutines.

The second part is entirely devoted to tables,the sole data structure in Lua.Its chapters discuss data structures,persistence, packages, and object-oriented programming.There we will unveil the real power of the language.

The third part presents the standard libraries.This part is particularly useful for those that use Luaas a stand-alone language,although many other applicationsalso incorporate all or part of the standard libraries.This part devotes one chapter to each standard library:the mathematical library,the bitwise library,the table library,the string library,the I/O library,the operating system library,and the debug library.

Finally,the last part of the book covers the API between Lua and C,for those that use C to get the full power of Lua.The flavor of this part is necessarily quite different from therest of the book.There, we will be programming in C, not in Lua;therefore, we will be wearing a different hat.For some readers,the discussion of the C API may be of marginal interest;for others, it may be the most relevant part of this book.