Required Background

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The text assumes no preparation in the theory of programming languages, but readers should start with a degree of mathematical maturity—in particular, rigorous undergraduate coursework in discrete mathematics, algorithms, and elementary logic.

Readers should be familiar with at least one higher-order functional programming language (Scheme, ML, Haskell, etc.), and with basic concepts of programming languages and compilers (abstract syntax, BNF grammars, evaluation, abstract machines, etc.). This material is available in many excellent undergraduate texts; I particularly like Essentials of Programming Languages by Friedman, Wand, and Haynes (2001) and Programming Language Pragmatics by Scott (1999). Experience with an object-oriented language such as Java (Arnold and Gosling, 1996) is useful in several chapters.

The chapters on concrete implementations of typecheckers present significant code fragments in OCaml (or Objective Caml), a popular dialect of ML. Prior knowledge of OCaml is helpful in these chapters, but not absolutely necessary; only a small part of the language is used, and features are explained at their first occurrence. These chapters constitute a distinct thread from the rest of the book and can be skipped completely if desired.

The best textbook on OCaml at the moment is Cousineau and Mauny's (1998). The tutorial materials packaged with the OCaml distribution (available at http://caml.inria.fr and http://www.ocaml.org) are also very readable.

Readers familiar with the other major dialect of ML, Standard ML, should have no trouble following the OCaml code fragments. Popular textbooks on Standard ML include those by Paulson (1996) and Ullman (1997).

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