SIGPLAN

This paper discusses some language features which might have been in ALGOL68. They would not have complicated the compiler to any considerable extent. They would certainly have contributed to the expressive power of the language. In fact their ...

Algol 68 is a very suitable language for tackling problems which lie somewhere between numerical calculation and algebraic manipulation. An algorithm is presented which evaluates a function of n variables and its n partial derivatives using at most C.m ...

Information concerning the run-time behaviour of programs (“program profiling”) can be of the greatest assistance in improving program efficiency. Two software devices have been developed for use on ICL 1900 Series machines to provide such information.

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In this paper we describe how a software testbed is used to determine the quality of testing of Algol 68 programs. The system monitors the execution of an Algol 68 program and obtains a run-time execution history. This history is then compared with the ...

Some questions of run-time storage management for ALGOL 68 are discussed. In the first section it is shown that in many cases copying of already existing values is not necessary, in spite of the fact that the Report prescribes this. The second section ...

The relative merits of LL and LR parsing methods are compared, particular reference being made to ALGOL 68. The fact that LR methods can be applied to a wider class of languages does not seem to give them a significant advantage in practice.

By making use of its advanced and highly expressive facilities, Algol 68 can be used to implement interpretive language processors with an unusual degree of conceptual clarity and machine independence. The internal representations of source programs in ...

Code generation is very complex. Using ALGOL68, complexity increases due to the recursivity of the manipulated values. The set of routines manipulating values will be recursive too. Describing such a manipulating process with flow charts makes it less ...

If the transput section of an ALGOL-68 compiler is to be portable, it must be described in such a way that it is clear which aspects are machine-dependent, and which are not. There should be a clear set of primitives underlying the transput. In this ...

The problems concerning SIZETY definitions in an Unabridged Machine-Independent Standard Prelude for ALGOL 68 are examined and tentative solutions are given.

This paper describes some of the techniques which can be used for managing the run time storage required for an ALGOL68 program. The emphasis is on stack storage, since garbage collection techniques would require another paper. The problems caused by ...

This paper describes the problems and solutions of a particular “pulled” bootstrap transportation of the Cambridge ALGOL68C compiler; in particular, the problems encountered in making the external appearance of the compiler system conform to the ...

This paper is an introduction to the portable ALGOL 68 implementation currently developed at the Technical University of Berlin. An overview over the compiler and the other system components is given and the facilities for separate compilation and ...

The ALGOL-68 compiler of the University of Paris-XI (Orsay) has been implemented for Univac's 1110-series, under EXEC-VIII. It can compile the “full language” (including formats, unions, flexible arrays, recursive modes, parallel computation, etc.). It ...

A tool for the systematic production of test cases for a compiler is first presented. The input of the generator are formal grammars, derived from the definition of the reference language. This tool has been applied to the generation of test programs ...

Among the formalisms used for the definition of programming languages, context-free grammars are widely and satisfactorily used, but their power is limited. Augmented with attributes they can express context sensitive aspects of a language. In this ...

We consider briefly some of the problems encountered in the initial implementation of a system to automatically convert Fortran programs to Algol 68.

An album of modes, operators and procedures has been implemented to provide SNOBOL-like character string pattern matching facilities for the Algol 68 programmer. Most of the primitive functions and operators of SNOBOL 4 are included in the album. This ...

The implementation in Algol 68R of a cross assembler for the PDP11 minicomputer to run on the ICL1900 is described. The assembler duplicates the features of the PAL11 assembler. RRE's Syntax Improving Device was used for a two pass assembly system. The ...

A method is described of introducing to absolute beginners basic concepts of structured programming, including constructing programs by “step-wise refinement”. This is interleaved with a “top-down” description of a simple mini-subset of ALGOL 68, which ...

The use of 'functors' is proposed to generalise the ideas of abstract data and representation, and it is shown that these ideas have further uses in setting up libraries of algorithms. The properties of functors are discussed.

The paper describes the experiences of a small team in writing a substantial ALGOL 68 program to model the shapes of engineering components. The application derives much advantage from structures, operators and the heap. It includes a command ...

The paper outlines the use of ALGOL 68R in the production of a series of simulation models for a Multi Radar Tracking feasibility study. Particular reference is made to the use of structures, the chaining mechanisms used and the modularity of the ...

In many situations the atoms in a list can require a considerable amount of storage space or can be difficult to evaluate. When handling algorithms which only refer to a few atoms of a list much time and space can be wasted if the whole list is stored. ...

It is often believed that Pascal is - Algol68 in miniature - well “structured”.

It will be argued in Part One of this paper that both beliefs are badly founded.