Importing Pre-packaged Software into Lisp: Experience with Arbitrary-Precision Floating-Point Numbers

Abstract

We advocate the use of Common Lisp as a powerful glue for building scientific computing environments. Naturally one then has to address mixing pre-existing (non Lisp) code into this system. We provide a specific example as an elaborate FORTRAN system written by David Bailey for arbitraryprecision floating-point numeric calculation. We discuss the advantages and disadvantages of wholesale importing into Lisp. A major advantage is being able to use state-of-the art packaged software sooner, while overcoming the disadvantages caused by FORTRAN's traditional batch orientation and weak storage model. In this paper we emphasize in particular how e#ective use of imported systems may require one to address the contrast between the functional (Lisplike) versus state-transition-based (Fortran-like) approaches to dealing with compound objects. While our example is high-precision floats, other highly useful packages including those for simulation, PDE solutions, signal processing, statistical comp..