Notes on C programming for APL programmers

Abstract

As the domain of "callable" languages from APL increases, it is quite likely that APL programmers will find an increasing need for the ability to program in other languages as part of their support activities for APL programming. This is already becoming prevalent in mainframe APL2 (APL2/370), where it is not uncommon to find hybrid systems consisting of APL2, REXX, and/or FORTRAN.Since most "external language" activity in APL-based systems centers on manipulating APL arrays, it is appropriate to examine the programming techniques in callable languages from the standpoint of facilitating APL array manipulation. Specifically, C language programming techniques for handling APL2/PC arrays are reviewed. The techniques discussed emphasize isolation of the application code from the underlying array structure, thus maximizing application code portability. While immediately applicable to the management of APL2/PC arrays, the programming techniques and tips offered are applicable to other APL array implementations as well.