The book being reviewed is ``Programming in Ada 2012'' by John Barnes (ISBN 978-1-107-42481-4). Information concerning it may be found here.
I started learning Ada in late 2018 by reading the latest ``Ada Reference Manual'', and even later I took the advice of other Ada programmers to read this book being reviewed. It wasn't heavy reading, but I've a habit of making good progress and then allowing the book to languish for weeks or months; I read it unevenly throughout 2019 and finished it this month; part of my reason for this is how one is able to program in Ada reasonably well before finishing, with my doing so by chapter twenty-four.
This book is easier reading than the ``Ada Reference Manual'', which is most concerned by detailing. I'm to understand there aren't many choices with Ada books, it's also rather lengthy, but this isn't egregious alone; the book is delightfully free of a modern rot found within other programming books. Most every chapter is dedicated to an aspect of the language, and it's organized well for reference.
The book is well-typeset; particularly pleasant are lists of differences comparing previous versions of the language, resulting from the book's repeatedly-updated nature. Interspersed between chapters are six example programs of decent length exemplifying different qualities of the language, although I'd write such programs differently. Chapters are also accompanied by a review summary. The author does a fine job of explaining how complex machine rules give way to their simple human explanations.
The appendices of the book form a more formal reference I'll be using for the remainder of my owning it. The entire book forms a nice reference, owed to structure. Given its long length, I do find it absurd that anything is kept outside, stored instead in the WWW; the book could be far more concise.