Khrisnamurthi and Politz wrote:Many people would regard this as being two books in one. One book is an introduction to programming, teaching you basic concepts of organizing data and the programs that operate over them, ending in the investigation of universally useful algorithms. The other book is an introduction to programming languages: a study, from one level up, of the media by which we structure these data and programs.

Obviously, these are not unrelated topics. We learn programming through one or more languages, and the programs we write then become natural subjects of study to understand languages at large. Nevertheless, these are considered sufficiently different topics that they are approached separately. This is how we approached them, too.

The one noble exception to this separation is the best computer science book ever written, The Structure and Interpretation of Computer Programs.

We have come to realize that this separation is neither meaningful nor helpful. The topics are deeply intertwined and, by accepting that interleaving, the result is likely to be a much better book. This is my experiment with that format.