Some APL2 programming examples using nested arrays

ABSTRACT

Three extracts from a program currently in use are shown and discussed. The program reads seven files, formats the data as nested arrays, and prepares several reports and files. The examples are taken, respectively, from the input, process, and output sections of the program. In each section nested arrays are useful. N-WISE REDUCTION is used as the inverse of SCAN to simplify a backward scheduling algorithm. The flexible formatting of nested array output makes optimum use of print columns. An experimental depth operator described in the references is very useful.

REFERENCES

• 1: N. D. Thomson, Cultivating trees - an essay in APL2, Proceedings of the international conference on APL, p.343-348, June 11-15, 1984, Finland
• 2: A. P. Benkard, Symmetries of the firing squad sychronization problem revealed in a nested array, Proceedings of the international conference on APL, p.19-27, December 1987, Sydney, Australia
• 3: J. Philip Benkard, Replicate each, anyone?, ACM SIGAPL APL Quote Quad, v.17 n.4, p.245-252, May 1987
• 4: J. Philip Benkard, Structural experiments with arrays of functions, ACM SIGAPL APL Quote Quad, v.15 n.4, p.166-172, May 12, 1985

INDEX TERMS

Primary Classification:
  D. Software
  D.3 PROGRAMMING LANGUAGES
      D.3.2 Language Classifications

          Nouns: APL

Additional Classification:
  E. Data
  E.1 DATA STRUCTURES
      Subjects: Arrays

  F. Theory of Computation
  F.2 ANALYSIS OF ALGORITHMS AND PROBLEM COMPLEXITY
      F.2.2 Nonnumerical Algorithms and Problems
          Subjects: Sequencing and scheduling

General Terms:
Algorithms, Languages, Theory