[XeTeX] unicode-math package and \UnicodeMathSymbol command

[Ross Moore]

Hi Will,

On 23/06/2009, at 12:44 PM, Will Robertson wrote:

> On 2009-06-22 15:20:07 +0930, Ross Moore <ross at ics.mq.edu.au> said:
>
>>>  i'm just trying to use the command defined there, not define it   
>>> myself.  once i
>>> \usepackage{unicode-math}, \UnicodeMathSymbol seems to be in  
>>> scope  since i am
>>> able to call it without error, but also without the desired effect.
>>>   am i missing something here?
>> That is because you are not supposed to mess with it, unless you
>> know what you are doing.  :-)
>> Will defines it to do nothing, because you may be tempted to play.
>> He wants to make that kind of playing around totally ineffective,
>> and he seems to have achieved this aim admirably.
>
> Haha, that's not exactly what my intention was, but okay :)

Sure.
But you can do very good things without intending to.
For instance ...

>
> The file unicode-math.tex is supposed to be a "database" of sorts,  
> with \UnicodeMathSymbol simply acting as a logical wrapper around  
> each entry. Hence the totally useless fourth argument that just  
> contains a description of the codepoint,

   ... this is not useless at all.
Besides helping someone to know when they have found the
correct character within your file, it could also be used ...

> which I'd never include in a "command" to set up the behaviour of  
> the character/macro.

  ... within macros to supply "Alternative Text" to be read
by a screen-reader.  (e.g. "Read Out Loud" in Adobe Reader).

This is exactly what will be useful with the new standard
   ISO-32000-1  based upon "tagged PDF".
I'm doing work on this at present, for pdfTeX as the engine.

XeTeX cannot do this until Apple, and/or other OS vendors,
adjust the way they build their PDF output.
Or maybe the option for such /Alt tagging exists already?

Maybe Jonathan can comment on this.

>
> Features that we're talking about to change the meaning of various  
> symbols in different contexts require another interface on top;  
> this interface doesn't really exist at the moment.

Indeed.
But a user can always do it with a macro that specifies
the specific math class;  e.g.
         \newcommand{\hashprod}{\mathrel{\#}}
to use # as the symbol for a kind of multiplication.
Of course it would be nice to be able to write  $ A # B $
instead of   $ A \hashprod B $.

>
> Will

Cheers,

	Ross

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Ross Moore                                       ross at maths.mq.edu.au
Mathematics Department                           office: E7A-419
Macquarie University                             tel: +61 (0)2 9850 8955
Sydney, Australia  2109                          fax: +61 (0)2 9850 8114
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