Structuring functions with operators

ABSTRACT

Flow control for APL functions is limited to the simple GOTO facility supplied by the → arrow. Numerous papers have suggested enhancements to APL which provide flow control structures. This paper investigates to the extent to which control structures can be implemented in APL solely by means of features that already exist in the language, specifically by the use of primitive or defined operators. The exercise offers both a means to improve the quality of APL code and also affords an insight into the use of operators and their limitations. The paper assumes the use of APL2 or other compatible dialects such as APL.68000.

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INDEX TERMS

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

          Nouns: APL

Additional Classification:
  D. Software
  D.3 PROGRAMMING LANGUAGES
      D.3.3 Language Constructs and Features
          Subjects: Control structures; Procedures, functions, and subroutines

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

General Terms:
Algorithms, Design, Languages