Re: [Groff] gkurz, a short introduction for german users

[Werner LEMBERG]

> > - At many places you put a hyphen ('-', yields '‐') where a
> >   hyphen-minus sign ('\-', yields '-') would be more
> >   appropriate. Especially in command-line options. The hyphens not
> >   only look strange in command-line options, they also don't work:
>
> Forgive me for poking my nose in here, but I wanted to ask about
> that particular problem in order to make sure I have the DocBook
> manpages stylesheet doing what it should.
>
> So, to be clear, is the following description correct?
>
> If you put a U+002D HYPHEN-MINUS character into the source for a
> groff file, in certain environments (e.g., in a UTF-8
> environment), it will get output as a U+2010 HYPHEN character.

Yes.

> And, by the way, if the above is correct, is there a documented
> rationale for why groff outputs a U+2010 for it instead of a U+002D?
> (Some Unicode recommendation?)

This is to avoid ambiguity.  From glyphuni.cpp:

  // `-' and `hy' denote a HYPHEN, usually a glyph with a smaller
  // width than the MINUS sign.  Users who are viewing broken man
  // pages that assume that `-' denotes a U+002D character can either
  // fix the broken man pages or apply the workaround described in the
  // PROBLEMS file. 

and from the PROBLEMS page:

  * The UTF-8 output of grotty has strange characters for the minus, the
    hyphen, and the right quote.  Why?

  The used Unicode characters (U+2212 for the minus sign and U+2010
  for the hyphen) are the correct ones, but many programs can't search
  them properly.  The same is true for the right quote (U+201D).  To
  map those characters back to the ASCII characters, insert the
  following code snippet into the `troffrc' configuration file:

  .if '\*[.T]'utf8' \{\
  .  char \- \N'45'
  .  char  - \N'45'
  .  char  ' \N'39'
  .\}


     Werner