On 27 Nov 2015 9:18 pm, "Stephen Berman" <stephen.berman@gmx.net> wrote:
> > No. We don't support having multiple characters match a single string.
>
> Is this why "ss" does not match the German letter "ß"?

Indeed.

> I assume the
> reason "s" does not match "ß" is that the latter does not have a
> decomposition including "s", whereas the decomposition of e.g. "ff" does
> include "f", correct?

Yes.

> In fact, looking at the value of character-fold-table, it seems to me
> that the current implementation of folding based on character
> decomposition often yields surprising results: e.g. "f" matches not only
> "ff" but also "㎙" and "ffl", but "m" and "l" fail to match the latter two,
> respectively.

This was by choice, and it would be trivial to change. Do others find it
surprising?

> Another shortcoming is that the decompositions do not respect
> case-folding, e.g. "f" fails to match "ℱ" and "℻" (with case-folding
> enabled), whereas "F" does match them, but fails to match "ff".

True. This can be fixed, I think. Could you file a bug report so we don't
forget?