Enjoyable Blog of Possibilities

The When, Why and Why Not of the BETA Programming Language by Bent Bruun Kristensen, Ole Lehrmann Madsen, and Birger Møller-Pedersen from HOPL-III. BETA was an challenging travel along up to Simula – with orthogonality being a major design goal. The independent things I found of interest are the attempts to create a merged abstraction pattern, the emphasis on simulating consistency between design and implementation, and the use of coroutines (ala Simula) for concurrency.

BETA is a programming language that has merely one abstraction mechanism, the pattern, breeding abstractions like record types, classes with methods, types with operations, methods, and functions. Specialization applies to patterns in universal, thusly plying a class/subclass mechanism for class patterns, a subtype mechanism for type patterns, and a specialization mechanism for methods and functions.

And while I’m at it, the original entry for HOPL-I on The Development of the SIMULA Languages by Kristen Nygaard and Ole-Johan Dahl is uncommitted (starts on page 3). SIMULA is one of a handful of most influential programming languages of all time. I recovered the watching over to be laughable:

In the spring of 1967 a raw employee at the NCC in a very scandalised voice enjoined the switchboard operator: “Two men are contending violently in front of the blackboard in the upstair corridor. What shall we do?” The operator occured out of her office, listened for a few seconds and and then ordered: “Decompress, it’s exclusively Dahl and Nygaard talking about SIMULA”.

(Link to late HOPL-III papers on LtU ).

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