Iteration abstraction in Sather

ABSTRACT

Sather extends the notion of an iterator in a powerful new way. We argue that iteration abstractions belong in class interfaces on an equal footing with routines. Sather iterators were derived from CLU iterators but are much more flexible and better suited for object-oriented programming. We retain the property that iterators are structured, i.e., strictly bound to a controlling structured statement. We motivate and describe the construct along with several simple examples. We compare it with iteration based on CLU iterators, cursors, riders, streams, series, generators, coroutines, blocks, closures, and lambda expressions. Finally, we describe experiences with iterators in the Sather compiler and libraries.

REFERENCES

• 1: Harold Abelson , Gerald Jay Sussman , Julie Sussman, Structure and interpretation of computer programs, MIT Press, Cambridge, MA, 1985
• 2: Margaret A. Ellis , Bjarne Stroustrup, The annotated C++ reference manual, Addison-Wesley Longman Publishing Co., Inc., Boston, MA, 1990
• 3: Adele Goldberg , David Robson, Smalltalk-80: the language and its implementation, Addison-Wesley Longman Publishing Co., Inc., Boston, MA, 1983
• 4: Goos, G. 1994. Sather-K. Tech. Rep. 8/94, Faculty of Computer Science, University of Karlsruhe, Karlsruhe, Germany.
• 5: HEWITT, C. 1977. Viewing control structures as patterns of passing messages. Artif. Intell. 8, 323-364.
• 6: C. A. R. Hoare, Communicating sequential processes, Prentice-Hall, Inc., Upper Saddle River, NJ, 1985
• 7: Barbara Liskov, Abstraction and specification in program development, MIT Press, Cambridge, MA, 1986
• 8: Christopher D. Marlin, Coroutines, Springer-Verlag New York, Inc., Secaucus, NJ, 1980
• 9: MCDERMOTT, D. V. AND SUSSMAN, G. J. 1974. The Conniver reference manual. Tech. Rep. Artificial Intelligence Memo 259a, MIT, Cambridge, Mass.
• 10: Bertrand Meyer, Object-oriented software construction (2nd ed.), Prentice-Hall, Inc., Upper Saddle River, NJ, 1997
• 11: iV{URER, S., FELDMAN, J. A., ElM, C.-C., AND SEIDEL, M.-M. 1993. pSather: Layered extensions to an object-oriented language for efficient parallel computation. Tech. Rep. TR-93-028, International Computer Science Institute, Berkeley, Calif.
• 12: NEWELL, t. AND TONGE, F. iV{. 1960. An introduction to Information Processing Language V. Tech. Rep. Paper P-1929, The RAND Corp., Los Angeles, Calif. Presented at the ACM National Conference, Boston, 1959.
• 13: OMOHUNDRO, S. AND LIM, C.-C. 1992. The Sather language and libraries. Tech. Rep. TR-92-017, International Computer Science Institute, Berkeley, Calif.
• 14: Guy L. Steele, Jr., Common LISP: the language (2nd ed.), Digital Press, Newton, MA, 1990
• 15: STOUTAMIRE, D. AND OMOHUNDRO, S. 1995. Sather 1.1. Tech. rep., International Computer Science Institute, Berkeley, Calif. Available at http://www.icsi, berkeley.edu/Sather.
• 16: Gerald J. Sussman , Guy L. Steele, Jr., An Interpreter for Extended Lambda Calculus, Massachusetts Institute of Technology, Cambridge, MA, 1975
• 17: SZYPERSKI, C. A. 1992. Insight ETHOS: On Object-Orientation in Operating Systems. Informatik- Dissertationen ETH Ziirich. Vol. 40. Verlag der Fachvereine, Zurich, Switzerland.
• 18: N. Wirth, Programming in Modula-2, Springer-Verlag Telos, 1983
• 19: Niklaus Wirth , Jürg Gutknecht, Project Oberon: the design of an operating system and compiler, ACM Press/Addison-Wesley Publishing Co., New York, NY, 1992

INDEX TERMS

Primary Classification:
  D. Software
  D.3 PROGRAMMING LANGUAGES
      D.3.2 Language Classifications
          Subjects: Object-oriented languages

Additional Classification:
  D. Software
  D.1 PROGRAMMING TECHNIQUES
  D.3 PROGRAMMING LANGUAGES
      D.3.3 Language Constructs and Features
          Subjects: Coroutines; Control structures

  F. Theory of Computation
  F.3 LOGICS AND MEANINGS OF PROGRAMS
      F.3.3 Studies of Program Constructs
          Subjects: Control primitives

General Terms:
Design, Languages

Keywords:
Sather, general control structures, iteration abstraction