Support unicode character please

[fy0]

Most of modern programing languages already allows unicode variables names, please add this feature.
Thanks to contributors for the great work.

[fy0]

Temporary solution:

Read file to buffer, and convert to ascii

strconv.QuoteToASCII(buffer)

Then use:

Identifier <- ![0-9] (UniversalCharacter / [0-9a-zA-Z_])+


#-------------------------------------------------------------------------
#  A.1.4  Universal character names
#-------------------------------------------------------------------------

UniversalCharacter
   <- '\\u' HexQuad
    / '\\U' HexQuad HexQuad

HexQuad <- HexDigit HexDigit HexDigit HexDigit

HexDigit        <- [a-f] / [A-F] / [0-9]

[flowchartsman]

This would be really swell; I was evaluating this as a replacement for pigeon, but the grammar I was working on allows for unicode identifiers, and I'd rather not have to use an awkward workaround.