[XeTeX] xetex and xfrac?

[Axel E. Retif]

On  4 Dec, 2008, at 04:50, Axel E. Retif wrote:

> On  3 Dec, 2008, at 10:46, Stephen Moye wrote:
>
>> I have tried to get xfrac to work using xetex and fontspec, but have
>> had only limited success. If, for example, I set

[...]

>> \DeclareInstance{xfrac}{"Goudy Std"}{text}{%
>> 	slash-right-kern = 1pt,
>> 	slash-left-kern	= 1pt,
>> }
>>
>> but this does not seem to do anything. [...]
>
> I guess xfrac doesn't understand fonts that way, but with the tfm
> family names (cmr, for Computer Modern; hlh, for Lucida, etc.); but  
> try
>
> \DeclareInstance{xfrac}{default}{text}{%
> 	slash-right-kern = 1pt,
> 	slash-left-kern	= 1pt,
> }
>
> This will affect sfrac in san serif and italics as well, though.

There is a way to avoid this ---say you don't want that change in your  
san serif font, but only in roman and italics, then

\DeclareInstance{xfrac}{default}{text}{%
	slash-right-kern = 1pt,
	slash-left-kern	= 1pt,
}
\DeclareInstance{xfrac}{sanserif}{text}{%
	slash-right-kern = 0pt,
	slash-left-kern	= 0pt,
}

\sfrac{1}{2}, \textit{\sfrac{1}{2}}, \textsf{\sfrac[sanserif]{1}{2}}.

Best,

Axel