Re: Case mapping of sharp s

[Kenichi Handa]

In article <address@hidden>, Ulrich Mueller <address@hidden> writes:

> In Unicode since version 5.1.0 the U+1E9E code point is assigned to
> "LATIN CAPITAL LETTER SHARP S". Would it be possible to add a mapping
> from this to the lower case ß, as in the patch below?

> However, I've noticed that similar mappings for Turkish ı (dotless i)
> and İ (I with dot) were commented out [1]. Is it still so that such a
> change would "make searches slow", as stated in the comment?

That kind of setting surely makes the searching of ß and ẞ
slow because we can't use BM search when case-fold-search is
non-nil.  BM search is possible only when all
case-equivalent characters are represented by the same byte
length, and differ only in the last byte.

So, if you are sure that searching of ß is very rare (I have
no idea), please install it.

By the way, I think it's possible to improve the current
BM-search for such a case.  For instance, to search
"straße", we at first do BM-search for "stra" part and then
check the remaining "ße" part.  Aren't there any challenger?

---
Kenichi Handa
address@hidden