[XeTeX] babel

[Tobias Schoel]

Hi,

[snip]

> Two possible smartfont techniques for such locale feature are:
> - alternate french punctuation marks with larger sidebearings: this is
> very unflexible for users (punctuation characters without additional
> space or with different space width are troublesome) but of course
> simplifies the typesetting engines’ troubles the most.
> - contextual variant of the <non breaking space> character: the
> typesetter or their engine has to enter a space at the correct place
> that then gets replaced by a (narrower) variant; here I think the
> engine’s troubles aren’t really diminuished a lot, but the users’ might
> rise. What’s more, contextual lookups that involve <space> don’t work
> with XeTeX, so this is not very lucky here too.
As far as I know, TeX's view of spaces is to not handle them as 
characters but as space without characters. So I don't understand, why 
French Spacing should change in any way between pdftex and xetex. Space 
without characters doesn't care for encoding nor fonts, because there is 
no character to be encoded or handled in any way by a font.

>
> Unicode already provides for a bunch of different space characters. IMO,
> type designers should provide their fonts with appropriate space
> characters (eg. 6-per-em space or thin space) and the typesetter or
> their engine should check for the presence of that character and use it.

Even if whitespace is left to the font, which is perfectly reasonable 
but not the TeX way, why should French Spacing be left to the font at all?

It's simply checking for a flag that says "I want French Spacing" and 
then including white space (in whatever form) at appropriate places. You 
can take appropriate white space from the font according to your liking 
(there are many in space codepoints in unicode) or do it yourself. At 
the most you can ask unicode to include a special "Space in front of 
some punctuation in French"-codepoint, but I doubt that would be 
successful nowadays.

BYe

Toscho