Re^3: sorting Chinese characters

[choroba]

in reply to Re^2: sorting Chinese characters
in thread sorting Chinese characters

Why are you using English locale for Chinese?

It would not be surprising if the Unicode support was weaker in C# than in Perl, but I have no experience witn C# and it is not mentioned in Unicode Good, Bad, & Ugly.

I have no experience with sorting Chinese. I have studied articles like What's wrong with sort and how to fix it, though, and at work I am dealing mostly with Czech, which fortunately uses Latin letters (plus some less common diacritics like ř or ů), but whose "official" sorting algorithm is unfortunately practically unimplementable (e.g. numbers should be sorted as pronounced).

[larryk]

I have three indexes and only one is Chinese. If I needed a 'display sort' (i.e. I was going to show the index keys to the user) then I'd specialise my indexing class and use a native locale for the key type. However, in this case, the keys only need to be internally consistent between index creation (Perl) and consumption (C#). I was expecting that Unicode support between the two languages would be sufficiently mature that I could rely on the defined standard.

As it turns out, when I re-sorted the index in a debugging session in C# and then diffed the Perl index vs. the C# index, there were fewer differences than unreachable keys. A large block of mis-sorted entries were disrupting the binary search for proximate entries (including 'one') and then there were two or three Chinese characters which were sorting oddly between the two languages in a few places, which were causing the rest of the dead-ends.

By excluding these few entries during index creation, I now have 100% match.

If I get some time it'll be interesting to find out why those few characters are really being sorted in a different order. Might be a bug in either C# or Perl.

Anyway, thanks for your help.