Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!samsung!zaphod.mps.ohio-state.edu!sunybcs!rutgers!bellcore!flash!sdh From: sdh@flash.bellcore.com (Stephen D Hawley) Newsgroups: comp.lang.forth Subject: Re: Why is Postscript not Forth? Message-ID: <19928@bellcore.bellcore.com> Date: 10 Feb 90 23:54:47 GMT References: <431.UUL1.3#5129@willett.UUCP> Sender: news@bellcore.bellcore.com Reply-To: sdh@flash.UUCP (Stephen D Hawley) Organization: Bellcore, Morristown, NJ Lines: 32 In article <431.UUL1.3#5129@willett.UUCP> dwp@willett.UUCP (Doug Philips) writes: >In trying to understand the essence of what 'Forth' is, I've been >trying to understand why many Forth supporters don't want to call >PostScript Forth. Speed of execution of a language is not what is important. Yes, most implementations of postscript are pretty slow, and for good reason. PS is heavily dependent on floating point arithmetic. It doesn't have to be, but the language was heavily designed to not be constrained for typesetting. How high will your resolution be? 72 dpi? (NeXT screen, NEWS screen?) 300 dpi? (Laserwriters, QMS Colorscript) 400 dpi? (NeXT printer) 600 dpi (Varityper)? 900 dpi (Linotronics) etc etc. Did you know that the Apple laserwriter carries enough floating point precision to print text the size of Cleveland? Carrying all this extra baggage is what slows PS down, but that doesn't have to be so. So is PS Forth? Well, that's unclear. Forth is a bizarro language. It's not so much a language as a set of loose semantics. I can put a layer on top of forth that will make it look like BASIC. Is BASIC Forth? People have mentioned implementations of Scheme layered on top of Forth. Is Scheme Forth? Of course you can carry this much further, since every useful computer language is equivaleny to every other. I put it that, no, PS is not Forth, but merely similar in semantics. Steve Hawley sdh@flash.bellcore.com A noun's a special kind of word. It's ev'ry name you ever heard. I find it quite interesting, A noun's a person place or thing.