Open
Description
There's many invisible unicode characters.
https://invisible-characters.com/
We currently disallow several of them
Line 596 in c245179
Namely
'\u00ad' # soft hyphen
'\u200b' # zero width space
'\u200c' # zero width non-joiner
'\u200d' # zero width joiner
'\u200e' # left-to-right mark
'\u200f' # right-to-left mark
'\u2060' # word joiner
'\u2061' # function application
It appears the reference parser also attempts to disallow '\u115f' # Hangul Choseong filler
, but this doesn't work due to Base.is_id_char
returning true for that character. I'm not sure this is a problem, I didn't find obvious information about what this filler character is for and whether it might be required for writing identifiers in Korean.
Anyway, should we disallow more of the list from https://invisible-characters.com/ ?