Rating: 

While not intended as an introducton to Objective-C, given a decent background

in programming languages and the ways of the OO world, it is a concise, dense,

and immensely informative overview of Objective-C. The OO world in general

and Objective-C in particular relies heavily on idioms (sometimes called "design

patterns") and this work does a good job of introducing some of the most

important parts of the dialect. It also covers the OpenStep dialect where that

differs significantly.

The discussion of metaclasses deserves special mention because previous

"explanations" I've read usually generated more heat than light. Even in this

compact form, the discussion of this nettlesome topic is as straightforward

and lucid as I've seen.

In general, there is a great paucity of works which can serve to introduce

a new programming language to journeyman programmers who do not

need binary addition explained yet again. We have quite enough

"Dummies" books - we need more "<FOO> for the Already Clueful".

I hope O'Reilly will continue developing books in this vein. I know they

must be very hard to write as the amount of information distilled into this

one is remarkable. The writing skill and natural abilities for pedagogy

required for a project like this are equally daunting. But I look forward

to further efforts like this one. The author has set a high bar.

Even if you aren't particularly drawn to learning Objective-C, read

this to see how explaining a programming language ought to be done.