Talking with an APL via DDE: teaching an old dog new tricks

ABSTRACT

Shared variables and auxiliary processors are well-known techniques for connecting alien applications to APL. The use of APL in the PC windowing multitasking environment of MS Windows, which incorporates a messaging model for interprocess communications, requires some new approaches to the implementation of shared variable and auxiliary processor support. This paper presents a shared variable interface to MS Windows graphics written in Microsoft C and a simple charting package called TinyPlot written in Dyalog APL for Windows (Dyalog APL/W). The purpose of this paper is to demonstrate and investigate the Dyalog APL/W shared variable and auxiliary processor facilities, and to offer observations and conclusions about the benefits, limitations, and potential of the Dynamic Data Exchange interface generally.

REFERENCES

• 1: James A. Brown , Erik Kane, APL2 implementation of cross-system shared variables, ACM SIGAPL APL Quote Quad, v.23 n.1, p.34-39, July 1992
• 2: Smith, Gordon S. "Simplify client-server applications using the DDE Management Library", Microsoft Systems Journal, Vol. 7, Number 8, pp. 61-75 (1992, December).
• 3: "Networked DDE", LAN Technology, Vol. 7, Number 11, p. 91 (1991, November).
• 4: Derfler, Frank Jr., and Rigney, Steve. "Windows for Workgroups", PC Magazine, Vol. 11, Number 21, pp. 255-261 (1992, December).
• 5: FRESCO User Manual, Mr. APL Inc., 1988.

INDEX TERMS

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

          Nouns: APL

Additional Classification:
  D. Software
  D.2 SOFTWARE ENGINEERING
      D.2.2 Design Tools and Techniques

          Nouns: Windows
  D.3 PROGRAMMING LANGUAGES
      D.3.4 Processors
          Subjects: Optimization

General Terms:
Algorithms, Languages