Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!natinst!sequoia!memqa!r91400
From: r91400@memqa.uucp (Michael C. Grant)
Newsgroups: comp.lang.postscript
Subject: Re: PostScript Level II, contextual forms
Message-ID: <5805@memqa.uucp>
Date: 30 Aug 90 16:51:18 GMT
References: <9607@goofy.Apple.COM> <1289.26d27708@waikato.ac.nz> <1330.26d576c4@waikato.ac.nz> <1990Aug24.182905.24152@ico.isc.com> <1376.26dc15f6@waikato.ac.nz>
Organization: Memory R&QA, Motorola SPD
Lines: 39

In article <1376.26dc15f6@waikato.ac.nz>, ccc_ldo@waikato.ac.nz (Lawrence D'Oliveiro, Waikato University) writes:
> Are you suggesting that all these applications reinvent the writing-system-
> dependent aspects of text handling? Isn't PostScript important precisely
> because of the fact that it provides a common solution to several common
> problems of text handling? Wouldn't it be nice if it were extended to solve
> more of them?

Okay, tell me the flaw in this logic:
Assume that Postscript handles contextual forms for me.  So, if I send
it the 'gloop' character, there might be four or five different ways
that it would print out, depending upon its 'surroundings'.

Great.  Now, assume that we DON'T have Display Postscript.  How in the
world are we going to display these forms on the screen before we
send them to the laser printer?  Easy, just DUPLICATE THE WORK
PERFORMED BY POSTSCRIPT IN THE APPLICATION.

Sorry, but I don't like doing things twice!

Now, let us assume that there is more than one code for the 'gloop'
character--a unique code for each of its forms (just as there is a separate
code for capital and lowercase 'a', for example).  Now, either the user
or the application chooses the proper form, and send that UNIQUE code to
the PostScript printer.  Voila--the printer does not have to interpret
the code contextually, it just runs through the lookup table as always.

Sure, contextual forms are usually more complex that 'A' vs. 'a', but
the idea is similar: we press the SHIFT key to get 'A'.  Why not press
a special key, for example, to get the end-of-the-word representation
of an Arabic letter, or the katakana versus hiragana representations
of a Japanese character?  When we write by hand, we must make that
adjustment, and so it is quite natural for us to think this way.

I really don't see why the latter scenario, in which the contextual
interpretation is performed ONCE (and rather quickly, I might add),
than the former scenario, in which it is performed at least TWICE,
if not EVERY time the character is displayed on the screen.

Michael C. Grant