[XeTeX] Space characters and whitespace

[Philip Taylor (Webmaster, Ret'd)]

mskala at ansuz.sooke.bc.ca wrote:
> On Thu, 3 Mar 2011, Philip Taylor (Webmaster, Ret'd) wrote:
>> if XeTeX is predicated on the use of Unicode, it should
>> "understand" the semantics of Unicode code points such
>> as u2009 and u202F and just do the right thing without
>> having to hack things through the use of active characters.
>
> There are really three separate questions here:
>
> 1.  Should XeTeX accept Unicode's many space characters in the input, as
> opposed to just using existing TeX commands for spacing?
>
> 2.  If the answer to #1 is "yes," what exactly should be the consequences
> of each space character?  Grouping this under the same question because
> it's related:  to what extent should the font determine the width and
> nature of each space character?
>
> 3.  If the answer to #1 is "yes," how should this be implemented - in
> particular, should it be in the engine or by macros?
>
> It sounds like you're saying "yes" to #1 and "in the engine, not in the
> macros" to #3.

Yes, I am; it does not seem to me to make sense to implement the glyphs
of Unicode without also honouring its non-glyph-contributing elements.

** Phil.