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From: don@brillig.umd.edu (Don Hopkins)
Newsgroups: comp.lang.forth
Subject: Re: Forth in PostScript
Message-ID: <22573@mimsy.umd.edu>
Date: 16 Feb 90 08:03:33 GMT
References: <456.UUL1.3#5129@willett.UUCP> <459.UUL1.3#5129@willett.UUCP>
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Reply-To: don@brillig.umd.edu (Don Hopkins)
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
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In article <459.UUL1.3#5129@willett.UUCP> dwp@willett.UUCP (Doug Philips) writes:
>	I don't think I stated my point clearly.  What I'm trying to do
>is to get at the 'essence' of Forth.  I know that Forth and PostScript
>are not the same thing (species), but I know that they probably belong
>to the same genus.  In trying to understand Forth, it is as helpful for
>me to understand what Forth *isn't* as it is to understand what Forth
>*is*.  PostScript is the candidate I chose because it is so similar to
>Forth that the distinctions between the two seemed to me as if they
>would be very informative as to the subtleties of Forth's essence.
>One difference that has been pointed out as important is the typing of
>PS's stack.  I'm curious to know what the other (if any) important
>differences are.
>
>		-Doug
>
>---
>Preferred: willett!dwp@gateway.sei.cmu.edu OR ...!sei!willett!dwp
>Daily: ...!{uunet,nfsun}!willett!dwp   [in a pinch: dwp@vega.fac.cs.cmu.edu]

Yes, PostScript and Forth are very different languages, but also very
similar, each quite good for different things. But comparing
programming languages is like comparing mind altering chemicals.
Metaphores can only go so far. After a certain point, you just have to
try them yourself or accept what experienced users tell you on faith.
Caffeine does different things to me than nicotine. The most I can
tell you in so many words is that one makes me stay up and one makes
me throw up. If you want to know more you're going to have to try them
yourself.

I think that after all the excellent explanations that have been
posted here describing the differences and similarities of PostScript
and Forth, the only way you're going to arrive at any deeper an
understanding of the two languages is by using both of them.  Learn
them both, by programming in them, or at least studying some heavy
duty code. By heavy duty PostScript code I don't mean a program that
prints out your typical company logo, troff2ps output, or a laserprep
header file. At least read the Green book from Adobe, or the NeWS Book
from Springer Verlag. It also helps to know Lisp to appreciate
PostScript.

Me, I get my rocks off by reading and writing PostScript and Forth.
Your mileage may vary. If you have access to anonymous ftp you can
grab lots and lots of free PostScript code for the NeWS window system
from tumtum.cs.umd.edu (it's also on the latest SUG tape). If you
don't but are really interested I can send some select pieces your
way, just ask. 

	-Don