On Revival of Algol-Concepts in Modern Programming and Specification Languages - Formal Methods and Hybrid Real-Time Systems - page 414

On Revival of Algol-Concepts in Modern
Programming and Specification Languages

Hans Langmaack

Institut fur Informatik
Christian-Albrechts-Universitat zu Kiel
Olshausenstr. 40, D-24118 Kiel, Germany
[e-mail]

Abstract. Appearance of computing machines dates back to the 1940s
and their corresponding scientific disciplines, computer science resp. in-
formatics, have arisen in the 1960s. Nevertheless, fighting for appropri-
ate programming and specification languages has not yet come to an
end: The Java-programming language and the Abstract State Machines
ASM are new and representative specimens which have arisen recently.
These languages are even advancing and improving themselves: Original
Java 1996, a flat language language without class nestings, towards more
modern Java 2000 with nested classes, and Basic ASM resp. Evolving
Algebras 1988/91 towards Turbo ASM 2003 where machines and rules
show new features like naming, parameterizing, local states and recursive
calls. These transitions inside Java resp. ASM remind at a much earlier
transition from Fortran and Algol 58 to Algol 60 with its block concept
and nested, parameterized, recursive and formal procedures. Aim of the
present essay is to show that many of those new concepts incorporated
in new Java and Turbo ASM were already available in Algol60.

Keywords: Programming language, Algol, Java, block concept, formal
procedure, class, object, structural simulation, specification language,
Abstract State Machine ASM, recursive procedure and rule, semantics,
verification.

1 Introduction

Appearance of electronic universal computing machines dates back to the 1940s
and their corresponding scientific disciplines, computer science resp. informa-
tics, have arisen in the 1960s. Nevertheless, fighting for appropriate program-
ming and specification languages has not yet come to an end. On the contrary:
The Java-programming language and the Abstract State Machines ASM are
new and representative specimens which have arisen just recently in the 1990s.
And we realize that these languages are advancing and improving: Original Java

This essay is a contribution to the Festschrift Symposium at UNU/IIST Macao,
devoted to our dear colleagues Dines Bjørner and Zhou Chaochen on behalf of their
70th birthdays. Macao, 24th - 25th of September 2007.