Re: WIP patch: Collation support

On Tue, Sep 02, 2008 at 05:42:13PM +0100, Gregory Stark wrote:
> Martijn van Oosterhout <kleptog(at)svana(dot)org> writes:
> > On Tue, Sep 02, 2008 at 04:46:16PM +0300, Peter Eisentraut wrote:
> >> >While it's true POSIX locales don't handle this, other collation
> >> >libraries do and we should support them if the user wants.
>
> I think that's backwards. We have to go with the lowest common denominator
> functionality of those libraries if we're going to be portable.

And I think that's backwards. Why can we only use a feature once every
OS out there implements it? We still run on systems that don't have SSL
support. LC_TYPE settings are not portable between systems, yet that
doesn't bother anyone. Why should we have a problem with collate
settings not being portable?

> I don't think composable unicode characters are really about collations. I
> think it had more to do with representing glyphs in UTF32 before they gave up
> on that. Does anyone still use composable characters?

Lookup the various normalisations forms:
http://en.wikipedia.org/wiki/Unicode_normalization
In particular Normal Form D.

Sure, composable characters have nothing to do with collation, but they
provide a uniform way of doing accent insensetive collation.

> Note that we don't currently support composable characters at all.

Any character which is an accent on a latin character is a decomposable
character. And last I checked we supported those.

Have a niceday,
--
Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> Please line up in a tree and maintain the heap invariant while
> boarding. Thank you for flying nlogn airlines.