Re: search-default-mode char-fold-to-regexp and Greek Extended block characters, Re: search-default-mode char-fold-to-regexp and Greek Extended block characters

[Juri Linkov]

>     Juri> If there are many such cases, then better to handle them 
> automatically indeed
>     Juri> (if this doesn't cause slowdown too much) instead of adding them 
> one by one
>     Juri> to the default values.  Does this handle ß as well?
>
> There are 74, and I donʼt want to maintain such a list by hand :-).

Yes, 74 is too tedious to maintain by hand, so better to install your
previous patch (if it doesn't have the problem mentioned below) since
there are only 3 such complex characters (handled by your newer patch)
that is easy to add by hand:

  '((?ß "ss")
    (?ΐ "ΐ")
    (?ΰ "ΰ"))

> ß is not a complex character, so is never looked at here. But if we
> hoist the checking out of the loop over complex characters, we can
> make that work as well (this supersedes my previous patch).
>
> I have no idea of the performance impact of all this.
> [...]
> +                   (aset equiv (aref roundtrip 0)
> +                         (cons str (aref equiv (aref roundtrip 0))))))

It seems this adds a symmetric decomposition from the first character of "ss",
i.e. from ?s to "ß".  Shouldn't this rather update 'equiv-multi' instead?

OTOH, I see no reason to add symmetric decompositions by default since
they are handled by the option 'char-fold-symmetric'.