Nick Sabalausky wrote:
Thanks all for the helpful responses. Since we seem to have some real
Unicode-knowledge people here, I'd like to repost a question I had asked
elsewhere awhile back, but didn't get an answer:
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Can someone explain how folding-case differs from lower-case and why it
should be used for case-insensitive matching instead of lower-case?
I was looking at this document, but still don't get it:
http://www.unicode.org/reports/tr21/tr21-5.html
The only part I see that directly addresses that is this:
Case-folding is more than just conversion to lowercase.
For example, it handles cases such as the Greek sigma,
so that "?????" and "????S" will match correctly.
Which references what it says earlier about sigma:
Characters may also have different case mappings,
depending on the context.
For example, U+03A3 "S" capital sigma lowercases to
U+03C3 "s" small sigma if it is followed by another
letter, but lowercases to U+03C2 "?" small
final sigma if it is not.
But I still don't see how that demonstrates a need for anything other than
toLower provided that the given toLower routine is already properly handling
the "end of word"/"not end of word" difference.
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Unless, it's just extra speed due to not having to handle things like the
"end of word"/"not end of word" difference?
If you want to case-insensitive find "as" in " basdaS " in English, you
can just convert both to lower case, and you'll find them both.
Now suppose you want to find "as" in the string " basdas ", where it's
all in Greek. It still occurs twice, but it you convert it to lower
case, each s has a different character. toLower() doesn't work.
