Connecting Lisp-Stat to COM

Statistical software systems are just one, albeit a very important one, of several software systems used by data analysts. Data to be analyzed often resides in data bases or spread sheets; results of analyses are often presented in reports written in word processors or report generators. In recent years several mechanisms have been developed for connecting these and other applications, and more generally for allowing software entities to be developed as separate components. The two most important systems are the Common Object Request Broker Architecture (CORBA) [8, 9] and Microsoft’s Component Object Model (COM) [2, 7]. While arguably inferior in a number of respects, COM is, in terms of installed base, far more widely used. In particular, most major applications available on the Win32 platform use COM to provide a programatic interface by which they can be controlled by external programs. This paper describes an interface between one statistical system, Lisp-Stat [12], and COM. The emphasis is on the dynamic subset of COM known at the time of writing as Automation. After providing some brief background on Lisp-Stat and COM in Section 2, Section 3 uses a series of examples to show how the interface is used. Section 4 discusses issues in implementation and integration relevant to other statistical systems and other component systems. The final section offers some conclusions and presents some open issues. Many high level and interactive languages have been interfaced to COM. This work draws mainly on the Perl interface [10, 11] and the Haskell interface, described in a paper with a wonderfully descriptive title [4]. Other languages with COM interfaces include Python [13] and Tcl [14].