[XeTeX] STFangsong punctuation kerning

[Likai Liu]

Thanks to all who responded.

I found a way to manage lists in TeXbook Appendix D, Dirty Tricks (it's 
actually kind of neat!), so I was able to push the scalability part a 
bit further, but it took so much effort to rewrite the macros. I'm a 
bit baffled by how there isn't an easier way to do this, but I feel 
fortunate that with some programming genius, this can actually be done 
in TeX. I don't expect this flexibility in other typesetting systems.

I agree with Jonathan that the kosher way to do this is to use 
contextual alternate glyph substitution, but I suppose this is only 
implemented in more expensive fonts, and not those that came with Mac 
OS X.

Another question: the following code detects the "fullwidth" of a block 
character, but this only works for a given point size.

\newbox\fullspace
\setbox\fullspace=\hbox{¡@}% this is a full-width space character

\newdimen\fullwidth \fullwidth=\wd\fullspace
\newdimen\halfwidth \halfwidth=0.5\wd\fullspace

Is there a way to extend this for all font point sizes, like in the 
fashiong of em and ex units? (note: 1ex != \halfwidth)

liulk