bug#13041: 24.2; diacritic-fold-search

[Eli Zaretskii]

> From: Juri Linkov <juri@jurta.org>
> Date: Sat, 08 Dec 2012 01:55:22 +0200
> Cc: 13041@debbugs.gnu.org, perin@panix.com, perin@acm.org
> 
> This reminds an idea that searching should take into account the text
> displayed with the `display' property and other display-related properties.
> It seems this is more difficult to implement.

I don't know if it's more difficult.  After all, the primitives you
need to (a) find out whether there's a display string at given buffer
position, and (b) access its text, are already there, ready to be
used.  Moreover, there's even a C function that searches the current
buffer for a specific Lisp string, which you could use as a model for
this feature.

What is definitely true, though, is that searching display string is a
separate feature, with an entirely different implementation.  I
suggest therefore to keep it in mind, but not mix with what's being
discussed here.

> > I have no idea how many mappings like "ß" -> "ss" exist.  The problem is
> > that we don't get them from UnicodeData.txt IIUC.
> 
> I can't find them in UnicodeData.txt too.  Looking at the files in
> http://www.unicode.org/Public/UNIDATA/ can find them in the file
> 
> http://www.unicode.org/Public/UNIDATA/DerivedNormalizationProps.txt
> 
> that is derived from
> 
> http://www.unicode.org/Public/UNIDATA/CaseFolding.txt
> http://www.unicode.org/Public/UNIDATA/SpecialCasing.txt

Maybe we should extend ucs-normalize.el to include that as well.