[tex-live] Technical showstoppers for TL2003

[Vladimir Volovich]

"KB" == Karl Berry writes:

 HH> so, something:

 HH> write_mode = 0  % 0-255        as is
 HH> write_mode = 1  % 0-31         in ^^ notation
 HH> write_mode = 2  % 0-31 128-255 in ^^ notation
 HH> write_mode = 3  % whatever the locale wants

 HH> with write_mode = 0 being the default

 KB> Wouldn't specifying a tcx file be more general than this sort of
 KB> special parameter?

yes, it would be more general, but we should not allow TeX to use
non-1-to-1 mappings by default (without explicit specification of TCX
file), as it would be weird.

TCX has two effects:

1) it allows to map input characters to characters with the same or
   other codes (re-encoding of the input stream)

2) for all remapped characters, it changes the ^^-notation to the
   8-bit notation.

what we want to use (what is acceptable in the default TeX behavior,
as described in the TeXbook and in tex.web) is only the 2nd feature
(make certain chars outside of the 32-126 range printable too), and we
shall not allow any non-1-to-1 mapping for a single char.

therefore, i think that it might be better to avoid using TCX by
default (when no --translate-file is given), as it allows mappings
and we do not want to rely on TCX to not contain non-trivial maps.

so what Hans suggested looks better to me, except we shall perhaps
remove the write_mode=3 which may make the documents non-portable.

Best,
v.