ID_Start, ID_Continue, and stability extensions

Markus Scherer at
Thu Apr 24 15:56:22 CDT 2014

On Thu, Apr 24, 2014 at 12:56 PM, Steffen Nurpmeso <sdaoden at>wrote:

> Markus Scherer < at> wrote:
>  |I strongly recommend you parse the derived properties rather than trying
> to
>  |follow the derivation formula, because that can change over time.
> ..this file includes only those core properties that have
> themselves a derivation-may-change property?

I don't know what that means.

What I tried to say is, if you need ID_Start, then parse ID_Start from
DerivedCoreProperties.txt. That's more stable (and easier than parsing the
pieces and deriving

#      Lu + Ll + Lt + Lm + Lo + Nl
#    + Other_ID_Start
#    - Pattern_Syntax
#    - Pattern_White_Space


For example, at least one of the derivation formulas (for Alphabetic) is
changing from 6.3 to 7.0.

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