Re: Character entity mapping

Subject: Re: Character entity mapping
From: Anders Berglund <alb@xxxxxxxxxxxx>
Date: Thu, 28 Aug 1997 12:07:06 -0400
[Chris Maden]
>[Tony Graham]
>> Personally, I contend that &alpha; should come from the Symbol font,
>> and &agr; is what you should use if you want an alpha that looks
>> like ordinary text (i.e. from the Greek code page).
> 
>I agree, but unfortunately, ISO/IEC 10646 doesn't have different code
>points for mathematical and linguistic Greek:
> 
>geode-5> grep -i alpha iso10646.txt 
><A%>    /x03/x86        GREEK CAPITAL LETTER ALPHA WITH TONOS
><A*>    /x03/x91        GREEK CAPITAL LETTER ALPHA
><a%>    /x03/xac        GREEK SMALL LETTER ALPHA WITH TONOS
><a*>    /x03/xb1        GREEK SMALL LETTER ALPHA
> 
>Since DSSSL uses 10646 as its internal character model, I don't think
>there's a way to differentiate between the two characters without
>registering a new character.  Given 10646's limitations in the
>technical areas, I think JaDE is doing the best it can.

You are wrong in your description of the DSSSL character model - it is
correct for JADE which has this (current only??) implementation limitation.

It is precisely for reasons that you give that DSSSL does NOT use 10646 as its
internal character model - 10646 is only used as a possible (& convenient)
"shortcut" to a starting point of a character repertoire. A DSSSL "character"
is a named object in an INFINITE namespace (needed for eg technical symbols
- 10646 lacks close to 1000 of the ISO SDATA entities for math and technical
symbols -, publishing symbols, ideograms for Far Eastern languages - 
estimated for the need in Chinese are of the order of 50 000 to 100 000
different characters -, etc, etc). DSSSL also defined a mechanism for
mapping from these characters to glyphs.

Jade, at least in its current implementation, ONLY supports a single     
pre-defined character repertoire and ignores the various character
declarations defined in DSSSL.

Thus I do not think "JaDE is doing the best it can" - it could do
much better by implementing more of DSSSL!

Anders

> 
>-Chris

 DSSSList info and archive:  http://www.mulberrytech.com/dsssl/dssslist


Current Thread