Comments on the draft Pascal standard

46. R. P. Brent, T. Dwyer, S. J. Edwards, A. D. Glenn, D. A. Hawking, A. J. Hurst, C. W. Johnson, N. Justusson, T. Kelly, B. P. Molinari, D. L. Poole, J. M. Robson and I. R. Simpson, Comments on the draft Pascal standard, Australian Computer Science Communications 1 (1979), 310-317.

Also Technical Report TR-CS-79-09, Department of Computer Science, ANU, October 1979.

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Abstract

[Excerpts from the Introduction]

The draft Pascal standard is aimed at clarifying those areas in the language definition that were ambiguous or unclear. The result is disappointing. We found it most surprising that the committee did not give a more carefully formalized semantic definition of the language, as in the revised Algol 60 report for instance. The definition presented is somewhat informal and still imprecise, presenting some definitions by example, some in terms of poorly defined and loosely applied technical terms, and others by equivalent constructions using unstated methods of substituting constituents of the construct being defined.

The attempt to impose a standard that would make most current programs illegal is of concern to us. Although the definition of the language in some areas was previously uncertain in its written form, the defacto standard provided by the most available compilers should not have been rejected (e.g. in the area of type compatibility). In other areas the range of existing implementations has evidently caused the rejection of any standard (e.g. mod and div with negative arguments).

Comments

These comments are the result of discussions among members of the Canberra Pascal Interest Group. References are to the BSI draft Pascal standard published in IEEE Computer, April 1979, 68-82. The final version of the standard addressed some, but not all, of the issues raised here.

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