Eugene E. Kohlbecker

Revised 5 report on the algorithmic language scheme

The report gives a defining description of the programming language Scheme. Scheme is a statically scoped and properly tail-recursive dialect of the Lisp programming language invented by Guy Lewis Steele, Jr. and Gerald Jay Sussman. It was designed to have an exceptionally clear and simple semantics and few different ways to form expressions. A wide variety of programming paradigms, including imperative, functional, and message passing styles, find convenient expression in Scheme.

Hygienic macro expansion

Macro expansion in current Lisp systems is naive with respect to block structure. Every macro function can cause the capture of free user identifiers and thus corrupt intended bindings. We propose a change to the expansion algorithm so that macros will only violate the binding discipline when it is explicitly intended.

Revised 4 report on the algorithmic language scheme

The report gives a defining description of the programming language Scheme. Scheme is a statically scoped and properly tail-recursive dialect of the Lisp programming language invented by Guy Lewis Steele Jr. and Gerald Jay Sussman. It was designed to have an exceptionally clear and simple semantics and few different ways to form expressions. A wide variety of programming paradigms, including imperative, functional, and message passing styles, find convenient expression in Scheme.

A syntactic theory of sequential control

Abstract Sequential control operators like J and call/cc are often found in implementations of the λ-calculus as a programming language. Their semantics is always defined by the evaluation function of an abstract machine. We show that, given such a machine semantics, one can derive an algebraic extension of the λ υ -calculus. The extended calculus satisfies the diamond property and contains a Church-Rosser subcalculus. This underscores that the interpretation of control operators is to a certain degree independent of a specific evaluation strategy. We also prove a standardization theorem and use it to investigate the correspondence between the machine and the calculus. Together, the calculus and the rewriting machine form a syntactic theory of control, which provides a natural basis for reasoning about programs with nonfunctional control operators.

Revised Report on the Algorithmic Language Scheme

The report gives a defining description of the programming language Scheme. Scheme is a statically scoped and properly tail-recursive dialect of the Lisp programming language invented by Guy Lewis Steele, Jr. and Gerald Jay Sussman. It was designed to have an exceptionally clear and simple semantics and few different ways to form expressions. A wide variety of programming paradigms, including imperative, functional, and message passing styles, find convenient expression in Scheme.The introduction offers a brief history of the language and of the report.The first three chapters present the fundamental ideas of the language and describe the notational conventions used for describing the language and for writing programs in the language.Sections 5 and 6 describe the syntax and semantics of expressions, programs, and definitions.Section 7 describes Schemes built-in procedures, which include all of the languages data manipulation and input/output primitives.Section 8 provides a formal syntax for Scheme written in extended BNF, along with a formal denotational semantics. An example of the use of the language follows the formal syntax and semantics.The report concludes with a list of references and an alphabetic index and is followed by a short list of clarifications and corrections.

Macro-by-example: Deriving syntactic transformations from their specifications

This paper presents two new developments. First, it describes a “macro-by-example” specification language for syntactic abstractions in Lisp and related languages. This specification language allows a more declarative specification of macros than conventional macro facilities do by giving a better treatment of iteration and mapping constructs. Second, it gives a formal semantics for the language and a derivation of a compiler from the semantics. This derivation is a practical application of semantics-directed compiler development methodology.

Programming with Continuations

Progress in programming language design has often been achieved by making an abstraction a “first class object”, one that can be passed to and returned from procedures and entered in data structures. For example, the importance of functional parameters has long been recognized, though it is only more recently that actor semantics [2] and object oriented programming have demonstrated the power of first class functional objects. This paper illustrates, with a novel example, the power of first class control objects, called continuations.