Re: On language-dependent defaults for character-folding

[Eli Zaretskii]

> From: Óscar Fuentes <address@hidden>
> Cc: address@hidden
> Date: Fri, 12 Feb 2016 11:03:09 +0100
> 
> Eli Zaretskii <address@hidden> writes:
> 
> >> If ñ is meant to be read as ñ
> >
> > Don't you see them displayed identically in Emacs (and in any other
> > program that correctly implements display of combining accents)?
> > Maybe I don't really understand that "if" part.
> 
> They look a bit different here.

It could be an issue with your default font.  Perhaps it doesn't have
the precomposed glyph.

> ñ shall match ñ, but n shall not match either, from an Spaniard POV.

But in the case of 2 characters, a literal n is present in the buffer,
so not finding it would be a miss, don't you think?

> > Otherwise, I'm afraid I see
> > no sense in this logic: IMO identically looking text should match, or
> > else users will kill us.
> 
> Agreed, although in practice your example is not a big issue since I do
> expect to rarely see ñ (the composed variant) used in Spanish text. And
> probably not easy to implement at all for the general case (all
> identical-looking combinations for all languages).

We do that by using the Unicode database, because then we are free
from the need to decide whether a given diacrtic can or cannot combine
with a given base character.

> > If you agree that a match is TRT in these (and other similar) cases,
> > then you should agree that _some_ form of character folding should be
> > turned on by default.
> 
> I see where are you coming from ;-) On my first message on this thread I
> said that I was ambivalent wrt the default status of this feature,
> before finding the n/ñ issue. Not so after. A Spaniard could also deem
> useful to match ú and ü while searching for u. See, the problem here is
> not character-folding itsef, but how it works: a non-Spaniard could
> expect matching ñ while searching for n, because for him ñ is a `n' with
> a tilde, which is essentially the same case as the `u' example mentioned
> above but from the POV of someone who doesn't know Spanish. (*)

What about finding ⒜ when searching for a, don't you want to find
that?  This is not specific to any language.