Arrays of objects

ABSTRACT

This paper discusses key design decisions faced by a language design team while adding Object Oriented language features to Dyalog, a modern dialect of APL. Although classes and interfaces are first-class language elements in the new language, and arrays can both contain and be contained by objects, arrays are not objects. The use of object oriented features is optional, and users can elect to remain entirely in the functional and array paradigms of traditional APL. The choice of arrays as a "higher" level of organization allows APL's elegant notation for array manipulation to extend smoothly to arrays of objects.

REFERENCES

• 1: Bierman, Meijer and Schulte: The essence of data access in Cu , Microsoft (2005) http://research.microsoft.com/Comega/
• 2: Blasgen, M.W. and Eswaran, K.P.: Storage and access in relational databases. IBM Systems Journal 16, No. 4 (1977) http://www.research.ibm.com/journal/sj/164/ibmsj1604E.pdf
• 3: Kenneth E. Iverson, A programming language, John Wiley & Sons, Inc., New York, NY, 1962
• 4: Kromberg, Morten: Introduction to Object Oriented Programming for APL Programmers, available free with complete product documentation from http://www.lulu.com.
• 5: Mougin, Philippe and Ducasse, Stéphane: OOPAL: Integrating Array Programming in Object-Oriented Programming, Proceedings of ACM SIGPLAN, 2003.
• 6: Murphy, Paul: APL, COBOL & Dijkstra. http://blogs.zdnet.com/Murphy/?p=568
• 7: Scholes, John: D-Functions in Dyalog APL. http://www.dyalog.com/download/dfns.pdf
• 8: Thorup, Kresten: Contextual Class Extensions, AOP Workshop at ECOOP'97.

INDEX TERMS

Primary Classification:
  D. Software
  D.3 PROGRAMMING LANGUAGES
      D.3.3 Language Constructs and Features
          Subjects: Classes and objects

Additional Classification:
  D. Software
  D.3 PROGRAMMING LANGUAGES
      D.3.3 Language Constructs and Features
          Subjects: Data types and structures; Patterns

General Terms:
Algorithms, Design, Economics, Experimentation, Human Factors, Languages, Performance, Reliability, Theory

Keywords:
arrays, functional programming, language design, multi-paradigm languages, object orientation