Re: The hyphenchar ligature in T1

[Bernd Raichle <raichle@informatik.uni-stuttgart.de>]

On Tue, 3 November 1998 14:43:14 +0100,
Lars Hellström <Lars.Hellstrom@math.umu.se> writes:
[... compound words with explicit hyphens ...]
 > They are not too uncommon in Swedish either. It seems however, that this
 > will only work if the hyphenation pattern dictionary includes a pattern
 > that says that a breakpoint is always allowed after an explicit hyphen. As
 > I understand it, such a pattern is not necessary when using OT1 as TeX then
 > automatically inserts a \discretionary{}{}{} after every occurence of the
 > \hyphenchar.

...in outer mode.  This automatic \discretionary{}{}{} insertion is
not done in inner mode, i.e. inside an \hbox{...} no discretionary
node is inserted, even if it gets \unhbox'ed later.


 > Does this mean that you actually need to have two different
 > pattern dictionaries even for typesetting English---one for use with T1
 > fonts and one for use with OT1 fonts (provided, of course, that you use
 > both encodings) ?

No, the same pattern dictionary can be used for both.  If \hyphenchar
== `\- then the inserted \discretionary{}{}{} has the side effect,
that (a) hyphenation is prohibited and even if hyphenation is allowed
then (b) the patterns with an explicit hyphen won't match because of
the additional node.

Thus for german, I'm loading the pattern file ``ghyph31.tex'' (for OT1
_and_ T1 encoding) and _in addition_ the additional pattern file
``hypht1.tex'' which contains a lot of patterns for words with an
explicit hypen character.  I.e., both pattern files, which can be
found on CTAN, are loaded for the same \language number.


[...]
 > Quite so; if this is how they differ (in case they do in a given font) then
 > the hyphenchar should be used at linebreaks, not the hyphen.

TeX uses the \hypenchar\font at linebreaks.  Where's your problem? ;-)


[...]

Best wishes,
  -bernd