Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!jarthur!petunia!news From: jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) Newsgroups: comp.object Subject: Re: Global program state. Message-ID: <2789008e.3fdf@petunia.CalPoly.EDU> Date: 7 Jan 91 23:13:18 GMT References: <330@coatimundi.cs.arizona.edu> <2474@motcsd.csd.mot.com> Organization: Cal Poly State Univ,CSC Dept,San Luis Obispo,CA 93407 Lines: 21 > c) (back to the original topic of this thread) > you're not going to simplify this proof by eliminating "global state", > since what matters about the mac's behavior is precisely this state > (i.e. what's displayed on the screen, what's written to the disk, etc.). Good point. The global state of a program includes more than the program- defined memory locations. 'Functional' programs that manipulate I/O therefore must have global state... But from the programmer's perspective, object-oriented design encapsulates the screen, disk files, databases, comm channels, etc, as objects which have the behavior of that particular real-world entity. Thus the state aspects of those objects is still localized so as to help control complexity. -- John Dudeck "If it's Object Oriented then by jdudeck@Polyslo.CalPoly.Edu definition it's A Good Thing". ESL: 62013975 Tel: 805-545-9549 -- D. Stearns