Xref: utzoo comp.object:2365 comp.lang.functional:556
Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!usc!julius.cs.uiuc.edu!rpi!sci.ccny.cuny.edu!phri!cmcl2!kramden.acf.nyu.edu!brnstnd
From: brnstnd@kramden.acf.nyu.edu (Dan Bernstein)
Newsgroups: comp.object,comp.lang.functional
Subject: Re: Global program state.
Message-ID: <27109:Jan301:33:4391@kramden.acf.nyu.edu>
Date: 3 Jan 91 01:33:43 GMT
References: <27823155.211e@petunia.CalPoly.EDU>
Organization: IR
Lines: 16

In article <27823155.211e@petunia.CalPoly.EDU> jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes:
> In the book, _Principles of Functional Programming_, by Glaser, Hankin,
> & Till, it is stated, "the notion of global state that may change
> arbitrarily at each step of the computation has proved to be both
> intuitively and mathematically intractable."

That's a nice religion but it's simply not true. I am working on a
formal, quite mathematical, definition for the semantics of my Q
language. Q supports nonpreemptive threads and some amount of parallel
processing. It supports data hiding even better than Ada---Piercarlo, if
you're reading this, I stole your ideas about visibility in the opposite
direction. Yet the notion of global state proves quite useful in the
definition.

---Dan
Difference between Multics and Ada: Multics was ten years *ahead* of its time.