RE: char equivalence classes in search - why not symmetric?

[Drew Adams]

>   > I disagree. When I search for "Müller" I want it to also match
>   > "Muller" because some people (e.g., in French speaking countries) use
>   > this as an approximation of the spelling.
> 
> Are you suggesting that searching for ü should match u but not ú or ù?

I'm not speaking for Ulrich, but no, I am not suggesting that.

The proposal behind this thread is that when char folding is turned
ON, any char CHR in a given equivalence class would match any other
char in that class, when CHR is used in a search string.

So if char folding is on, you can find any of [eéèêæë] in the buffer
text using any of those chars in the search string, not just `e' in
the search string.  None of them has a privileged role in the search
string. 

To match only one of those folding-equivalent chars (e.g., only `e'
or `é'), you would turn OFF char folding and use that exact char in
the search string.

Char folding would be togglable, as now, using `M-s ''.  The only
difference would be that when char folding is on, any of [eéèêæë]
would act the same way in a search string.