Clojure in Action

One of the best programming books I've had the pleasure of working through, first edition and second.

CAVEAT: I'm only part of the way into the book, so consider this an in-flight reviewChapter 1 summary: "This was a long chapter!"Chapter 2 summary: "This was another long chapter!"Authors: You are right, these chapters are way too long.Chapter 1 covers, among other things: finding help with apropos, doc, and find-doc, whitespace, comments, data types nil string int float etc, symbols, keywords, lists, list functions list? conf peek pop count, vectors, vector fns get nth assoc, conj, peek & pop, maps map lookups, map fns assoc disassoc, assoc-in, get-in, update-in, sequences, sequence fns first rest cons, functions, def, fn, deffn, variable arity, the let form, underscore, the do form, the clojure reader, reader macros, conditionals if, if-not, cond, and when, logical fns and or not, comparators < <= >= =, = vs ==, and I'll skip the last 11 pages which cover loops & recursion, and threading functions, which could easily constitute their own chapters.Authors: If, in the course of organizing your book, you find yourself saying "gee, this chapter is really long..." this is a strong indication that it's TOO LONG. Split things up a bit for easier digestion. I read chapter one then went back to take notes on the chapter and it's taking me hours just to take notes on that single chapter. Otherwise I'm enjoying the book so far, but this lack of coherent and realistic organization is proving a serious hindrance to me getting through the book.

Clojure uses many parentheses and generally looks strange to many developers, and there's a reason for that, the two author note. "Clojure's syntax is derived from its Lisp roots: lots of parentheses. It's alien to most developers with experience in languages with Algol-inspired syntax like C, C++, Java, Python, Ruby, Perl, and so on." But Clojure also is an intriguing and powerful choice for software development projects, Amit Rathore and Francis Avila insist. It is "a functional Lisp on the JVM," and: "It is impossible to separate the Lisp, functional programming, and JVM features of Clojure. At every step they play on each other and tell a compelling software development story...."I have been studying and tinkering with Clojure on the side, at spare moments, for more than two years, using a disorganized approach of looking at web postings, building and modifying simple projects that others have posted, and sometimes looking at Clojure how-to books. From my perspective, Clojure in Action, 2nd Edition fills a beginner's need for a friendlier, more organized approach to learning the language and putting it to work effectively. And those already working with Clojure can benefit from having this book handy, too. It covers a lot of ground, using reasonably short paragraphs and offering many short code examples to illustrate its key points. This expanded 2nd edition covers the "new" features of Clojure 1.6. Of course, Clojure is now up to 1.8, but I have tried numerous code examples at various points in the book and not encountered problems. My thanks to Manning for sending me a review copy.

Clojure in Action got me up to speed quickly on implementing the Clojure model in some applications that I have been trying to model. The examples are clear and useful. If you're looking for a good introduction into Clojure along with solid examples and best practices you'll want to add this book to your library.

Nothing about SQL or databases. How is this useful to someone who works in IT? I don't like databases but they are part of the job if you work in IT. Why buy a book or use a language that don't address such a large part of what we do?

Coming from a background in Java, Clojure in Action helped me transition seamlessly into working in clojure. In a way, it reads like a lazy sequence, initially presenting just-necessary material and eventually filling in the gaps with more powerful Clojure concepts like immutability and macros. I enjoyed working through the book with a REPL nearby, and keep it on my desk as a reference at work.