Concepts and Semantics of Programming Languages 2. Therese Hardin

and simplicity, which inevitably leads to approximations and a lack of rigor, to some degree. Chapter 1 also proposes a set of questions to guide the acquisition of a language, with some answers given in the subsequent chapters. Chapter 2 first presents an implementation of kits with the modules of Ada and then a richer implementation of kits with the modules of OCaml. It ends with a much more succinct implementation of kits, referred to as weak kits, using the header files and the mechanisms of import–export of C. Chapter 3 takes up the kit model to handle classes and objects and their tools, for example inheritance, late binding and subclassing. This model is exemplified in Chapter 4, which presents the classes of Java, C++, OCaml and Python from a unified perspective.

      This work is aimed at a relatively wide audience, from experienced developers – who will find valuable additional information on language semantics – to beginners who have only written short programs. For beginners, we recommend working on the semantic concepts described in Volume 1 using the implementations in OCaml or Python to ease assimilation. All readers may benefit from studying the reference manual of a programming language, while comparing the presentations of constructs given in the manual with those given here, guided by the questions mentioned in Volume 2.

      Note that we do not discuss the algorithmic aspect of data processing here. However, choosing the algorithm and the data representation that fit the requirements of the specification is an essential step in program development. Many excellent works have been published on this subject, and we encourage readers to explore the subject further. We also recommend using the standard libraries provided by the chosen programming language. These libraries include tried and tested implementations for many different algorithms, which may generally be assumed to be correct.