[XeTeX] Whitespace in input

[Philip TAYLOR]

Is it safe to assume that these "code listings"
are restricted to the ASCII character set ?  If
so, yes, spaces are likely to be a problem, but
if the code listing can also include ligature-
digraphs, then these are likely to prove even
more problematic.

** Phipl.
--------
Ulrike Fischer wrote:

> One question which pops up regularly in the TeX-groups is "how can I
> insert a code listing in my pdf so that it can be copied and pasted
> reliably".
>
> Currently this is not easy as the heuristics of the readers can
> easily loose spaces, you can't encode tabs or a specific number of
> spaces.
>
> Real space characters in the pdf (instead of only visible space)
> would help here a lot.