Case transformations in strings

David-Sarah Hopwood david.hopwood at
Mon Mar 23 16:50:24 PDT 2009

Waldemar Horwat wrote:
> Allen Wirfs-Brock wrote:
>> Any input from our other Unicode experts would be appreciated...
>> Here's what I found (running on Windows Vista):
>> IE, FF, Opera
>> "\u00DF".toUpperCase()  returns "\u00DF"
>> Safari, Chrome
>> "\u00DF".toUpperCase()  returns "SS"
> The reason the ES3 specification was the way it was is because
> converting one character to many during case conversions would be
> incompatible with regular expressions.  The regular expression algorithm
> refers to String.prototype.toUpperCase.

If converting one character to many would cause a problem with the
reference to toUpperCase in the regular expression algorithm, then
presumably Safari and Chrome would hit that problem. Do they, or
do they use different uppercase conversions for regexps vs

If the latter, then we should allow that, and probably require it.

David-Sarah Hopwood ⚥

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