ID_Start, ID_Continue, etc.

[jacobfriedman]

I was looking for mention of ID_Start, XID_Start, ID_Continue and XID_Continie but can't find any documentation/code.

Is this a welcomed addition to this library?

https://www.unicode.org/reports/tr31/

[stevengj]

We already provide Unicode category codes, so you an use this to implement TR31 if you want.

(Julia supports a wider range of identifier characters, so we don't need this functionality ourselves.)