Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!chinacat!sequoia!memqa!r91400
From: r91400@memqa.uucp (Michael C. Grant)
Newsgroups: comp.lang.postscript
Subject: Re: PostScript Level II, contextual forms
Message-ID: <5600@memqa.uucp>
Date: 24 Aug 90 11:37:16 GMT
References: <9607@goofy.Apple.COM> <1289.26d27708@waikato.ac.nz> <1990Aug22.051728.16659@ico.isc.com> <1330.26d576c4@waikato.ac.nz>
Organization: Memory R&QA, Motorola SPD
Lines: 45

In article <1330.26d576c4@waikato.ac.nz>, ccc_ldo@waikato.ac.nz (Lawrence D'Oliveiro, Waikato University) writes:
> In <1990Aug22.051728.16659@ico.isc.com>, rcd@ico.isc.com (Dick Dunn)
> responds to my questions about support for contextual forms and interactive
> WYSIWYG editing as follows:
> 
> "PostScript is the wrong level to make such a decision.  At the level of
> PostScript, the output of text should be regarded as the output of a sequence
> of glyphs which have no inherent semantics.  Characters are simply objects being
> placed on the page or screen...it doesn't make sense to ascribe language-
> dependent context to them."
> 
> So, you need another layer on top of PostScript to implement these functions.
> Performance considerations aside, do you have a standard for this layer?
> Or does this mean that programs that want to be writing-system-independent
> cannot be operating-system-independent?

It seems to me that there are contextual forms in any language.  For example,
in English we capitalize certain words.  So, 'E' and 'e' are the same letter,
but just two different forms.  Now, if someone told me that I should just
type in all lower case, and let the Postscript printer convert the proper
lettters to uppercase for me, then I would laugh in his face :-)

Other languages, of course, are much more complicated in this respect,
however, but that doesn't change my point.  In my opinion, Dick Dunn is
right when he says that Postscript is not the place for contextual forms.
No, it is in the character set itself!  In other words, just as we have
two different ASCII codes for the letters 'E' and 'e', so would the Japanese
have two different codes for hiragana 'e' and katakana 'e', and all of the
kanji that sound like an 'e'.  It is the typists responsibility (usually)
to choose which character is appropriate!  After all, you don't expect
your pen and paper to automatically perform capitalization for you...

Now, in the case of Chinese and Japanese, I can understand the need for
another layer in which to ease the burden of the typist.  Some interesting
word processors in these languages allow them to type on a reduced keyboard,
while it chooses the proper characters to use based not only on the syntactic
context but the SEMANTIC context as well!  But, when it comes time to 
save the file to the disk, or SEND THE FILE TO THE PRINTER, each characteqr
has ALREADY been given its unique code.

A Postscript printer is simply a computerized pen and paper.  You have to
tell it WHAT to write, EXPLICITLY.  It makes to contextual judgements, just
as a normal pen an paper do not--that is left to the driving program.

Michael C. Grant