The road to Ruby mastery is paved with blocks, procs, and lambdas. To be a truly effective Ruby programmer, it’s not enough just to understand these features—you need to know how to use them in practice. Discover how to write code that is elegant, expressive, and a joy to use, and gain a deep understanding of these concepts so you can work with third-party gems and libraries more easily. Whether you are an intermediate or a seasoned Rubyist, you’ll find good use for these concepts in your code.
Disclaimer: I was one of the technical reviewers of this book - but my opinion on it is mine and has nothing to do with this fact. I wasn't paid for my review.
I found the book very interesting. Despite some grammar mistakes while proofreading, this book was great and I feel like the author: I have never used closures in Ruby before but I think I will if the need arises. And I will use closures better because this book has everything to get you from Zero to Hero!
This book will not be a game changer in ma developer career but it's more than worth of reading. It describes both ruby procs/blocks/lambdas and functional (ruby) closures very well, and as a bonus, it gives you a lot of hints and tips about how Ruby and its basic parts of metaprogramming work.