Before reading this book, I was proficient with Java, JavaScript, Python, and a few other languages — all primarily object-oriented and ALGOL-derived. Lisp and functional programming (FP) seemed alien and bizarre. But after hearing that people were getting real work done using FP with Scala and Clojure, and hearing Rich Hickey, the creator of Clojure, speak at Strange Loop 2011, I was inspired to get over my apprehension and learn functional programming and Clojure.

I decided it would be unwise to try to learn FP and Clojure at the same time, so I first wrote a program using FP in languages with which I was already familiar: CoffeeScript and Scala. It didn’t take long for me to build an appreciation for the paradigm.

Once I felt that I had a decent understanding of FP, I asked on Twitter whether anyone could recommend a book, and got a very enthusiastic recommendation from Sean Corfield for this one. It was available under O’Reilly’s pre-release program, so I was able to buy and read pre-release PDFs of the book.

The bottom line is that this book gave me a solid understanding of Clojure and enabled me to learn the language and gradually start using it. The concepts are presented in a thoughtful sequence and it’s made clear how each element of the language relates to the others.

The writing, examples, and organization are all excellent. And the book gets extra points for going beyond just explaining the language and how to use it, by being extra-comprehensive and covering how to really use the full Clojure ecosystem to build really useful software.

This is worth highlighting: if the book had been comprised of only chapter 1, “Down the Rabbit Hole”, and the first 2 parts, “Functional Programming and Concurrency” and “Building Abstractions”, it would have been an excellent book which I’d be recommending wholeheartedly. The inclusion of the subsequent parts, “Tools, Platform, and Projects”, “Practicums”, and “Miscellanea” make the book an invaluable resource and a fantastic value.

Ultimately, the book succeeds in conveying not only Clojure the language, but also the Clojure way, best practices, and key resources.

Three themes encompass the various improvements embodied in the iPad 2 and its accessories: speed, power, and ergonomics.

I don’t think I need to explain “speed” at all. By “power” I mean the ability to do things which weren’t possible or practical before; this includes the cameras, the gyroscope, the Verizon-compatible 3G radio, and the faster CPU and GPU — there’s some overlap between speed and power. I’m excited about those themes, but they’re pretty straightforward. I suspect that “ergonomics” requires more explanation.

The iPad 2 has many ergonomic improvements: lighter, thinner, rounded edges, flatter back, and the Smart Covers. These advances together will make the iPad 2 a significantly better experience than the first iPad. Being lighter and thinner means it’s easier to grasp in one hand with less fatigue over time. The flatter back means it’ll work much better on a flat surface such as a table or desk without a case or stand — the curved back of the first iPad made a case or stand essential. The Smart Covers will also enable more frequent use of the iPad without a case, because they’re so quick and easy to remove.

Combined together, we have a device which will be much easier and more pleasant to use without a case, more likely to be used without a case, and which when held in one hand will frequently be significantly lighter.

I understand why Apple wouldn’t market the iPad 2 using these themes; they’re too abstract for marketing. People generally want to hear about concrete improvements in new models. But there’s value in identifying and understanding the themes embodied in a new version of a product, so as to be able to make a holistic comparison with the older version.

Pros:

• great sound
• highly custamizable fit
• good passive attenuation of ambient sound
• separate microphone and control button makes both more convenient and effective
• high quality materials and construction
• iPhone-specific plug

Cons:

• can hear cord bouncing around as I walk, I think this is called subharmonics, I find it really annoying, but I think it’s a general problem with all “canalphones”, not just these.
• The phones seal really well, and don’t feed any of my voice into the audio, so I can’t hear myself speak, so I end up speaking very loudly – good for callers hearing mr, disconcerting for myself and people around me.
• callers hear a lot of ambient noise when I’m out on the street. (but I am in new york)

Bottom line: excellent headphones with a few quirks, which shine where it matters. And a great gift. Thanks Elina!

(Posted from my phone while walking through Central Park, listening to music, taking calls, and shooting some snapshots.)