Programming in Lua. 4 Ed

 This book does not assume any prior knowledge of Lua or any specific programming language —except for its last part, which discusses the Lua API with C. However, it assumes the knowledge of some basic programming concepts, in particular variables and assignment, control structures, functions and parameters, recursion, streams and files, and basic data structures.

 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. This book has much to offer to all these groups.

 Many people use Lua embedded in an application program, such as Adobe Lightroom, Nmap, or World of Warcraft. These applications use Lua's C API to register new functions, to create new types, and to change the behavior of some language operations, configuring Lua for their specific domains. Often, the users of such applications do not even know that Lua is an independent language adapted for a particular domain. For instance, many developers of plug-ins for Lightroom do not know about other uses of the language; Nmap users tend to think of Lua as the language of the Nmap Scripting Engine; many players of World of Warcraft regard Lua as a language exclusive to that game. Despite these different worlds, the core language is still the same, and the programming techniques you will learn here apply everywhere.

 Lua is useful also as a stand-alone language, not only for text processing and one-shot little programs, but for medium-to-large projects, too. For such uses, the main functionality of Lua comes from libraries. The standard libraries, for instance, offer pattern matching and other functions for string handling. As Lua has improved its support for libraries, there has been a proliferation of external packages. LuaRocks, a deployment and management system for Lua modules, passed one thousand modules in 2015, covering all sorts of domains.

 Finally, there are those programmers that work on the 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 Lua to create interfaces that are simple, easy to use, and well integrated with the language.