''Essentials of Programming Languages'' (''EOPL'') is a textbook on
programming language
A programming language is a system of notation for writing computer programs.
Programming languages are described in terms of their Syntax (programming languages), syntax (form) and semantics (computer science), semantics (meaning), usually def ...
s by
Daniel P. Friedman,
Mitchell Wand
Mitchell Wand is a computer science professor at Northeastern University. He received his Ph.D. from Massachusetts Institute of Technology
The Massachusetts Institute of Technology (MIT) is a Private university, private research universit ...
, and
Christopher T. Haynes.
EOPL surveys the principles of programming languages from an operational perspective. It starts with an
interpreter
Interpreting is translation from a spoken or signed language into another language, usually in real time to facilitate live communication. It is distinguished from the translation of a written text, which can be more deliberative and make use o ...
in
Scheme for a simple functional core language similar to the
lambda calculus
In mathematical logic, the lambda calculus (also written as ''λ''-calculus) is a formal system for expressing computability, computation based on function Abstraction (computer science), abstraction and function application, application using var ...
and then systematically adds constructs. For each addition, for example, variable assignment or thread-like control, the book illustrates an increase in expressive power of the programming language and a demand for new constructs for the formulation of a direct interpreter. The book also demonstrates that systematic transformations, say,
store-passing style or
continuation-passing style
In functional programming, continuation-passing style (CPS) is a style of programming in which control is passed explicitly in the form of a continuation. This is contrasted with direct style, which is the usual style of programming. Gerald Jay S ...
, can eliminate certain constructs from the language in which the interpreter is formulated.
The second part of the book is dedicated to a systematic translation of the interpreter(s) into
register machine
In mathematical logic and theoretical computer science, a register machine is a generic class of abstract machines, analogous to a Turing machine and thus Turing complete. Unlike a Turing machine that uses a tape and head, a register machine u ...
s. The transformations show how to eliminate higher-order closures; continuation objects; recursive function calls; and more. At the end, the reader is left with an "interpreter" that uses nothing but tail-recursive function calls and assignment statements plus conditionals. It becomes trivial to translate this code into a C program or even an assembly program. As a bonus, the book shows how to pre-compute certain pieces of "meaning" and how to generate a representation of these pre-computations. Since this is the essence of compilation, the book also prepares the reader for a course on the principles of compilation and language translation, a related but distinct topic. Apart from the text explaining the key concepts, the book also comprises a series of exercises, enabling the readers to explore alternative designs and other issues.
Like
SICP, EOPL represents a significant departure from the prevailing textbook approach in the 1980s. At the time, a book on the principles of programming languages presented four to six (or even more) programming languages and discussed their programming idioms and their implementation at a high level. The most successful books typically covered
ALGOL 60
ALGOL 60 (short for ''Algorithmic Language 1960'') is a member of the ALGOL family of computer programming languages. It followed on from ALGOL 58 which had introduced code blocks and the begin and end pairs for delimiting them, representing a ...
(and the so-called Algol family of programming languages),
SNOBOL
SNOBOL ("StriNg Oriented and symBOlic Language") is a series of programming languages developed between 1962 and 1967 at AT&T Bell Laboratories by David J. Farber, Ralph Griswold and Ivan P. Polonsky, culminating in SNOBOL4. It was one of a ...
,
Lisp
Lisp (historically LISP, an abbreviation of "list processing") is a family of programming languages with a long history and a distinctive, fully parenthesized Polish notation#Explanation, prefix notation.
Originally specified in the late 1950s, ...
, and
Prolog
Prolog is a logic programming language that has its origins in artificial intelligence, automated theorem proving, and computational linguistics.
Prolog has its roots in first-order logic, a formal logic. Unlike many other programming language ...
. Even today, a fair number of textbooks on programming languages are just such surveys, though their scope has narrowed.
EOPL was started in 1983, when Indiana was one of the leading departments in programming languages research. Eugene Kohlbecker, one of Friedman's PhD students, transcribed and collected his "311 lectures". Other faculty members, including Mitch Wand and Christopher Haynes, started contributing and turned "The Hitchhiker's Guide to the Meta-Universe"—as Kohlbecker had called it—into the systematic, interpreter and transformation-based survey that it is now. Over the 25 years of its existence, the book has become a near-classic; it is now in its third edition, including additional topics such as
types
Type may refer to:
Science and technology Computing
* Typing, producing text via a keyboard, typewriter, etc.
* Data type, collection of values used for computations.
* File type
* TYPE (DOS command), a command to display contents of a file.
* Ty ...
and
modules. Its first part now incorporates ideas on programming from
HtDP, another unconventional textbook, which uses Scheme to teach the principles of program design. The authors, as well as
Matthew Flatt Matthew Flatt is an American computer scientist and professor at the University of Utah School of Computing in Salt Lake City. He is also the leader of the core development team for the Racket programming language.
Flatt received his PhD at Rice U ...
, have recently provided
DrRacket
Racket is a general-purpose, multi-paradigm programming language. The Racket language is a modern dialect of Lisp and a descendant of Scheme. It is designed as a platform for programming language design and implementation. In addition to the co ...
plug-ins and language levels for teaching with EOPL.
EOPL has spawned at least two other related texts: Queinnec's ''Lisp in Small Pieces''
and Krishnamurthi's ''
Programming Languages: Application and Interpretation''.
See also
*''
Structure and Interpretation of Computer Programs
''Structure and Interpretation of Computer Programs'' (''SICP'') is a computer science textbook by Massachusetts Institute of Technology professors Harold Abelson and Gerald Jay Sussman with Julie Sussman. It is known as the "Wizard Book" in hac ...
''
*''
How to Design Programs''
References
{{reflist
Authors' home page for Essentials of Programming Languages, Third EditionBook homepage for first editionEoPL pageon Schemewiki
Computer programming books
Computer science books
Programming language topics