The Application of Halstead's software science. Theory to Algol 68 programs

Abstract

Abstract M. H. Halstead has argued that all computer programs are composed entirely of operators and operands. By counting these entities the software science theory then enables program properties such as vocabulary, length, volume, program level and language level to be calculated. For well written, or so‐called ‘pure programs’, one would expect, according to the theory, good agreement between certain observed and predicted values. Also, one might expect an intuitive ordering of language levels to be confirmed by the theory, with for example, Algol 68 having a higher language level than Fortran. In this paper two different counting strategies have been applied to one implementation of the Numerical Algorithms Group (NAG) Algol 68 library. The results do not entirely match expectation.