A Programmer's Guide to Common Lisp

Deborah G. Tatar

reviewed by Daniel Weinreb

Lisp has been around for more than twenty-five years. But for most of Lisp's lifetime, there haven't been any good books that teach the language. Only a few books were available, ranging from mediocre to awful.

There were two reasons for this. First, Lisp was used only within a few narrow communities, in which word-of-mouth instruction and a reference manual were sufficient to pass on knowledge of the language. There was not enough demand to justify a large printing of a book, or to attract the attention of good writers. Secondly, Lisp existed in many dialects, with common ideas and concepts but different naming conventions, syntax details, and so on.

In recent years, Lisp's popularity widened, and some more books started to appear, some of them better than anything that had come before. However, it was still hard to produce a good textbook because of the dialect problem. If you were writing such a book, as soon as you got past the most elementary features of Lisp, you had only two ways to go. First, you could stick to a small subset of primitives, and ignore all the rest of the features of Lisp. The resulting programs would run on almost any Lisp system, but were very awkward and usually showed poor programming style. Alternatively, you could pepper the text with warnings about how things might work one way in one dialect, another way in another, and so on, and provide appendixes describing the differences between dialects. This resulted in better programs but a more awkward writing style. Also, you could never cover all the dialects and subdialects, and the dialects were changing with time anyway.

Happily, this obstacle has been greatly reduced by the spread and general acceptance of the Common Lisp dialect. Now that Lisp is much more popular, and a common dialect is in wide use, many new books have appeared, and many existing books have been revised and re-issued in Common Lisp versions.

The Common Lisp language doesn't just unify the syntax of the Lisp that was around ten years ago. Many new capabilities were incorporated into Common Lisp, reflecting developments in the language that took place in the late Seventies and early Eighties. Of the existing books on Lisp, most spend relatively little time on these more modern features. Some books are intended for beginners, and cover the basics so thoroughly that they're over before they get to the modern features. Others are re-issued versions of books written for earlier dialects, in which those features weren't present. Some books have another goal, such as teaching artificial intelligence techniques, which also limits the depth to which the language is covered.

The modern features are defined in Common Lisp: The Language by Guy L. Steele . Jr., which is the reference manual for the Common Lisp dialect. However, Common Lisp: The Language is not intended as a textbook or tutorial. The manual defines the features, but doesn't spend much time explaining how to learn when to use them, and what you can do with them.

A Programmer's Guide to Common Lisp, by Deborah Tatar, distinguishes itself as the first textbook to cover not only the basics of the language, but the more modern