Subject: Re: bug#16731: 24.3.50; Latin small letter sharp s is not considered lower-case

From: Eli Zaretskii <[email-masked]>
Date: Thu, 13 Feb 2014 05:46:22 +0200

> Date: Wed, 12 Feb 2014 21:33:31 +0100
> From: Andreas Röhler <[email-masked]>
> CC: [email-masked]
> 
> Am 12.02.2014 21:16, schrieb Eli Zaretskii:
> >> Date: Wed, 12 Feb 2014 21:10:57 +0100
> >> From: Andreas Röhler <[email-masked]>
> >> CC: [email-masked]
> >>
> >> While upcase1 can't succeed, downcase should - if "ß" is a member of downcase_table.
> >
> > But which character do you want to downcase in this case?
> >
> > This whole logic works only for _pairs_ of characters (and the
> > char-table used here is populated by calls to set-case-syntax-pair).
> 
> So populate it differently, resp. allow empty slots.

How will we then be able to distinguish between lower-case characters
that have no upcase variant and characters that are not lower-case
characters at all?

> You can do (downcase "d") for example, which results in "d".
> 
> Instead of
> 
> upcase1 (c) != c
> 
> what about
> 
> downcase (c) == c
> 
> ?

The same is true for any non-letter, like punctuation.