[XeTeX]   in XeTeX

[Philip TAYLOR]

Chris Travers wrote:

> Ok, so why don't we have a similar macro here?  Something like:
> \obeynbsps

See above : there are /some/ things that TeX does that
transcend category codes (which are the basis for \obeylines);
in particular [1] :

"$$ TeX deletes any <space> characters (number 32)" that occur
  at the right end of an input line"

These are ASCII 32s, not \catcode 10s, and XeTeX itself would
require modification if you also wanted XeTeX to delete any
U+2009s, U+202fs, ... in the same way that it deletes normal
spaces.  This is without the aegis of \obeynbsp, which would
kick in long after this action has been irrevocably completed.

But in general, \obeyspecialUnicodespaces /might/ be viable !

** Phil.
--------
[1] "The TeXbook", page 46.  Pages 46 and 47 are well worth
studying in the context of this discussion.