UAX44: loose matching of symbolic values and the `is` prefix

Doug Ewell doug at
Tue Jun 7 09:56:46 CDT 2016

Mathias Bynens replied to Nova Patch: 

>> [...] Based on my past research for Unicode Regular Expression
>> Engines at IUC38, I suspect that there might not be any regex engine
>> that actually supports syntax like Script=IsGreek as described in
>> UAX44-LM3! If anybody knows otherwise, I’d love to hear about it. 
> This seems like a cut-and-dried case of reality not matching the
> specification, which is not helpful in any way. The sensible thing to
> do is to update the specification accordingly, as proposed. 

Rather than changing the spec based on anecdotal evidence, an even more
sensible thing to do would be to make this a Public Review Issue: "We're
considering simplifying this matching rule and need to know if any
implementers rely on the part we're planning to delete. Please send
feedback by $date."

There must have been some basis for including the "is" case in the first
place. It seems irresponsible to assume now that nobody anywhere needs

Doug Ewell | | Thornton, CO ����

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