Programming in Lua

Rating:
Summary: Your One Stop Lua Source
Review: I found Programming in Lua a good complement to the resources already available online.

Roberto shows flair in his writing and his various points about the language are sustained by concise but clear (and many times entertaining) programming examples.

In my limited Lua experience I have come across information similar to the one presented in Roberto's book in other places too. However, the book organizes the concepts well, systematically and, perhaps more importantly, in a consistent style (not to mention that is also well indexed).

For the beginner Lua programmers it offers handholding, for the programmers with extensive C background it shows how to replace conventional C idioms with more efficient Lua ones and, finally, for the hardcore Lua people it offers those glimpses of Lua code honed to perfection.

At fewer than 300 pages the book manages to cover the entire language while emphasizing on doing things the Lua way. I only wished there were more goodies in the book but, then, it only matches Lua's footprint!

For those people caring for their collection of programming books, I found the book's graphics sleek and, well, Lua-ish. I personally ordered two copies, one to sit in my personal library besides Stroustrup and other sacred, and one to use as a reference at work.

As a professional with many years of programming experience I recognize value in this book and recommend it to anyone that programs or wishes to program in Lua.

Marius Gheorghe

Software Team Leader
CableTest Systems Inc.
www.cabletest.com

Rating:
Summary: A valuable multi-level book
Review: Lua is a free scripting language with an interesting development history. It is a language that is gaining wider acceptance thanks to small size, readable syntax, expressive power, efficiency, ANSI C portability and easy two-way integration with C and C++. It is also useful as a data-description language that can be tailored to one's needs.

Written by the chief architect of the language, this book is aimed at programmers whishing to approach or to better understand Lua and the (often unsuspected) capabilities offered by a fully dynamic language.

Despite its deceptively small size (260 pages) and a plain, readable style with an eye-resting typesetting, "Programming in Lua" packs an impressive amount of information peppered with small, clear code examples to help digesting it; it reminds me of my favorite programming book: the K&R (Kernighan and Ritchie's "The C programming language"). It is a multi-level book that always gives something new at every reading.

Rather than offer a catalogue of functions (left to the downloadable reference manual), the book's four sections introduce capabilities, concepts and interesting techniques that may surprise programmers used to static languages.

The first section is devoted to the language itself, including not-so-common subjects like dynamic typing, multiple results, first-class functions, closures, iterators and coroutines. The following section shows how to build all sorts of data structures, from simple arrays and lists to packages and objects, using Lua's "tables" and the powerful idea of "metatables" that makes the language easily customizable.
The third section introduces the standard libraries (they are actually optional, e.g. in microcontroller applications) with special emphasis on the simple but versatile pattern matching capabilities.

The fourth and last section is different: aimed at system programmers, it explains in detail how to interface Lua and C, both to add new functions to Lua and to use Lua inside a C program (possibly called from programs written in other languages).

"Programming in Lua" covers version 5.0 of the language, which is now mature and stable. I am using Lua both as a general-purpose 'light' language for system tasks or small programs, and as an embedded language inside C++ applications: the combined power of the two languages is impressive. I liked this book a lot, I learned much from it and I've done it the honor of a place besides my well-thumbed K&R.

Rating:
Summary: Excellent book
Review: Lua is a gem among programming languages. Its designers have commendably placed a high value on keeping the language small, readable and portable. The diminutive size and simple syntax of Lua, however, belie a very rich, highly factored and stable architecture. It is a fun language in which to program. Lua dovetails beautifully with lower level languages by means of a C interface, and its drum tight language processor and libraries are right at home in event-driven graphical applications as well as console programs.

The excellent book "Programming in Lua" by Roberto Ierusalimschy provides developers with a broad summary of the language. The author includes a myriad of small examples, each of which is well focused and easily grasped. Different solutions to a given problem are often accompanied by benchmark figures. Prof. Ierusalimschy has an educator's gift for finding the appropriate level at which to write, and readers will appreciate the conversational nature of his writing. Unlike many programming language books, "Programming in Lua" has a strong content-to-fluff ratio throughout.

The book provides valuable explanations of language and library features which even the careful reader of the Lua reference manual might miss. In addition, over twenty C library entry points are discussed (and, thankfully, indexed) which are not mentioned in the reference manual.

It is hard to conceive of a software project which would not benefit from using Lua, both as an embedded component and as a standalone interpreter of scripts. The book "Programming in Lua" is valuable for anyone with an interest in this lovely language.

Rating:
Summary: Let the revolution begin
Review: The Lua programming Language has been around for a while but this book by Roberto Ierusalimschy will be a mark in its history. The book managed to surpass every expectation I had for it, and I was eager! From someone with no Lua knowledge to those with Lua klocs in their backs, this book will be a great companion in a nice to read trip down the Lua 5.0 lane.

The book begins with the basic Lua elements and structures and then advances through control structures, functions, iterators and coroutines. Iterators and coroutines are one of those language features that may confuse the first timers, but the author manages to show the concepts and inter relations between them in a way that clarified the issues even for a seasoned Lua programmer. Alas, make no mistake, the whole first part is totally worthwhile for non beginners.

The second part of the book shows one of Lua biggest assets: tables and metatables. I've seen people sneer at Lua at first glance and then convert themselves to Lua evangelists simply for the features of tables and metatables. The author does his magic and makes a whole set of apparently complex concepts flow by the reader as fluid and logical as they can be.

By the way, fluency is arguably one of the major benefits of this book. The reader is taken from substrate to substrate of the Lua way of life without even taking notice. Every end of chapter left me with the satisfaction of having been presented with one more facet of Lua and with the tranquility that everything was falling in place at the right timing.

After tables and metatables, the book presents the concepts of Packages and Object Orientation in Lua. If you had any doubt ever that Lua was able to sustain "real" Modular/OO programming, be prepared to replace your dogmas. The book not only clarifies how to do it in Lua but also shows how easy and clear the coding gets.

The author ends the second part of the book with a great chapter on Weak Tables. I have to admit that I was somewhat refractory to Weak Tables before I read this book, but after this single chapter I was converted. May the name "weak" not influence your judgment on those Weak Tables. They are great, and the book showed more about them than I was expecting.

The third part of the book focuses on the standard libraries. Those would be the Table, String, I/O, Operating System and Debug libraries. Instead of repeating the contents of the Lua reference manual, the author manages to show lots of new information about the libraries by the use of examples and clear explanations. There are some points in Lua that can indeed be quite idiosyncratic at a glance, but this book is more than enough to clarify every one of them.

The fourth and last part of the book brings us the Lua C API. For the beginner Lua programmer this part will probably be skipped, but for the average programmer and most of all for the hardcore Lua explorer, this part will be pure delight. C programming is not for the faint of heart, but having a Lua interface for your C library is akin to the jackpot of embedded languages in my opinion.

This part of the book shows that the task of wrapping C code for Lua is not only feasible, but easily done once you grasp the fundamentals. Have one thing in mind, this was no small task for the author. Describing such an plethora of resources and how to use them in six chapters demands a clear yet straight to the point approach, and once again the book shines through.

Step by step the author shows how to deal with the Stack, to get arguments from and return values back to Lua, to handle tables (even those big ones), to call Lua functions from C code, to call C functions from Lua code, to handle strings, to handle state (using the registry, references and upvalues), and last but not least to use userdata types and metatables in C.

The last chapter of the book brings two examples of the use of the C API, one offers a directory iterator and the other a really nice example of binding an existent library (expat) for Lua use. Lots of my questions on the C API were dismissed with those two examples.

I should also reserve a praise for the book index. Not only I've found it complete but it is easy to understand some details of the Lua structure only by glancing at the index pages.

Conclusion

Being one of the first readers of this book was not only a great honor but also a great surprise. As a Lua old timer, I wasn't expecting to be presented to so many novelties, subtleties and jewels of programming in almost every chapter. Was I wrong...

If you have not seen Lua until now, this book is THE starting point.

If you are acquainted with other versions of Lua but have not studied version 5.0, this book is a great shortcut for your new endeavors.

Finally, if you think Lua is your native language and no book could teach you something worthwhile, think again. I was grateful I didn't skip not even one paragraph.

We've got the language. We've got the book. Let the revolution begin... :o)